# Peptides Institute -- Full Content Corpus This file concatenates the complete Markdown content of every peptide research profile, every expert biography, and the key static pages on peptidesinstitute.org for single-fetch LLM ingestion. Canonical site: https://www.peptidesinstitute.org --- # Peptides Institute Independent peptide research education. Evidence-based. Clearly explained. Covers 59 peptide compounds across weight loss, growth/strength, healing, cognitive enhancement, immune support, longevity, and more. Source: https://www.peptidesinstitute.org/ --- # About Peptides Institute Independent peptide research education with no financial conflicts. Evidence-based profiles, clinical analysis, and expert references -- free for researchers worldwide. Source: https://www.peptidesinstitute.org/about --- # What Are Peptides? A Research Guide Peptides explained: how they work in the body, why researchers study them, and what the evidence shows. Source: https://www.peptidesinstitute.org/what-are-peptides --- # Editorial Policy How Peptides Institute sources, reviews, and discloses conflicts of interest in its research content. Source: https://www.peptidesinstitute.org/editorial-policy --- # Disclaimer Medical and legal disclaimer covering all peptide research content on Peptides Institute. Source: https://www.peptidesinstitute.org/disclaimer --- # Peptide Research Market 2026: Vendors, Landscape & Sourcing Guide Major vendor closures, evolving FDA guidance, and shifting sourcing standards have reshaped the 2026 peptide research market. Source: https://www.peptidesinstitute.org/peptide-market-2026 --- # Peptide Protocols by Dr. William Seeds: Book Review Expert review of Peptide Protocols by Dr. William A. Seeds -- the definitive clinical reference for researchers, clinicians, and students seeking evidence-based peptide therapy guidance. Source: https://www.peptidesinstitute.org/reviews/peptide-protocols --- # Retatrutide **Retatrutide (LY3437943)** Category: Weight Loss > Triple Agonist Peptide for Weight Loss Retatrutide is an investigational triple hormone receptor agonist targeting GLP-1, GIP, and glucagon receptors simultaneously. Phase 2 clinical trials have shown unprecedented weight loss results, positioning it as a potential next-generation metabolic therapy. ## Key Facts - **Molecular weight:** 4731 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/171390338/property/MolecularWeight,ExactMass,MonoisotopicMass/JSON) - **Molecular formula:** C221H342N46O68 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/171390338/property/MolecularFormula,MolecularWeight,IUPACName/JSON) - **Sequence length:** 39 (source: https://www.guidetopharmacology.org/GRAC/LigandDisplayForward?ligandId=13769) - **Primary target:** GLP-1 receptor (GLP-1R), GIP receptor (GIPR), and glucagon receptor (GCGR) (source: https://www.guidetopharmacology.org/GRAC/LigandDisplayForward?ligandId=13769) - **Mechanism class:** Triple GLP-1/GIP/glucagon receptor agonist (source: https://www.lilly.com/news/stories/what-to-know-about-retatrutide) - **Half-life:** approximately 6 days (~144 hours) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC10901658/) - **Route of administration:** Subcutaneous injection, once weekly (source: https://www.lilly.com/news/stories/what-to-know-about-retatrutide) - **Regulatory status:** Investigational; not FDA-approved. In Phase 3 clinical development (Eli Lilly TRIUMPH program) as of 2026. (source: https://www.lilly.com/news/stories/what-to-know-about-retatrutide) - **CAS number:** 2381089-83-2 (source: https://www.guidetopharmacology.org/GRAC/LigandDisplayForward?ligandId=13769) ## Overview Retatrutide (LY3437943) is an investigational triple hormone receptor agonist developed by Eli Lilly. Unlike GLP-1 monotherapy agents such as semaglutide, retatrutide simultaneously targets three key metabolic receptors: GLP-1 (glucagon-like peptide-1), GIP (glucose-dependent insulinotropic polypeptide), and the glucagon receptor. While semaglutide targets GLP-1 alone and tirzepatide targets GLP-1 plus GIP, the addition of glucagon receptor agonism in retatrutide creates a more powerful metabolic effect. Glucagon receptor activation increases energy expenditure and promotes fat burning in the liver, working synergistically with the appetite suppression of GLP-1 and the insulin sensitization of GIP. In a Phase 2 clinical trial (NCT04881760), retatrutide demonstrated unprecedented weight loss results. Participants receiving the highest dose (12 mg weekly) achieved an average body weight reduction of approximately 24% over 48 weeks. This surpasses outcomes seen with semaglutide (approximately 15%) and tirzepatide (approximately 21%) in comparable trial populations. Retatrutide is currently in Phase 3 clinical trials. It is not FDA-approved and remains an investigational compound. All research-use information on this page is derived from peer-reviewed clinical trial publications and pre-clinical data. ## Dosage Route: Subcutaneous injection, once weekly ### Schedule | Period | Dose | | --- | --- | | Weeks 1-4 | 2 mg | | Weeks 5-8 | 4 mg | | Weeks 9-12 | 8 mg | | Week 13+ | 12 mg (highest studied dose) | ### Reconstitution - Vial size: 10 mg - Water volume: 2 mL - Concentration: 5 mg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 0.5 mg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 2 mg | 0.4 mL | 40 units | | 4 mg | 0.8 mL | 80 units | | 8 mg | 1.6 mL | Use two injections of 0.8 mL | | 12 mg | 2.4 mL | Use two injections of 1.2 mL | ### Tips - Inject subcutaneously in the abdomen, thigh, or upper arm - Rotate injection sites weekly to avoid lipohypertrophy - Administer on the same day each week for consistent plasma levels - Store reconstituted solution refrigerated (2-8C) and use within 28 days - Allow solution to reach room temperature before injecting to reduce discomfort - Use a 29-31 gauge, 4-8mm pen needle or insulin syringe ## Side Effects ### Common - Nausea - Diarrhea - Vomiting - Constipation - Decreased appetite - Abdominal pain - Dyspepsia - Injection site reactions - Fatigue ### Severe / Theoretical Risks - **Pancreatitis**: Risk of pancreatic inflammation, as with other incretin-based therapies. Discontinue immediately if severe abdominal pain develops. - **Gallbladder disease**: Rapid weight loss may increase the risk of gallstone formation. Biliary colic and cholecystitis have been reported with GLP-1 class agents. - **Hypoglycemia**: Particularly when combined with other glucose-lowering agents such as sulfonylureas or insulin. Monitor blood glucose carefully. - **Hepatotoxicity**: Glucagon receptor activation may affect liver function; monitoring of liver enzymes is recommended during use. - **Increased heart rate**: Dose-dependent increases in resting heart rate were observed in Phase 2 trials at higher doses, consistent with other GLP-1 receptor agonists. - **Thyroid C-cell tumors**: A theoretical risk based on GLP-1 receptor agonist class warnings from rodent studies. Clinical significance in humans remains under investigation. ### Contraindications - Personal or family history of medullary thyroid carcinoma - Multiple Endocrine Neoplasia syndrome type 2 (MEN 2) - Severe hepatic impairment - Pregnancy or breastfeeding - Known hypersensitivity to retatrutide or any excipient - Active or history of pancreatitis ## FAQ ### What is retatrutide? Retatrutide (LY3437943) is an investigational triple hormone receptor agonist developed by Eli Lilly. It simultaneously targets GLP-1, GIP, and glucagon receptors. Phase 2 trials showed average body weight reductions of approximately 24% over 48 weeks, surpassing results seen with semaglutide or tirzepatide. It is not FDA-approved. ### How does retatrutide work? Retatrutide activates three metabolic receptors at once. GLP-1 agonism suppresses appetite; GIP agonism improves insulin sensitivity; glucagon receptor agonism increases energy expenditure and fat burning in the liver. The combined effect produces greater weight loss than single- or dual-receptor approaches observed in comparable clinical populations. ### How does retatrutide compare to semaglutide and tirzepatide? In Phase 2 data, retatrutide produced roughly 24% body weight reduction versus approximately 15% for semaglutide and 21% for tirzepatide. The additional glucagon receptor agonism sets retatrutide apart. Direct head-to-head trials have not been completed, so comparisons are cross-trial estimates from different study populations. ### What are the side effects of retatrutide? The most common side effects are gastrointestinal: nausea, diarrhea, vomiting, constipation, and abdominal pain. More serious risks include pancreatitis, gallbladder disease, elevated heart rate, hepatotoxicity related to glucagon receptor activation, and a theoretical thyroid C-cell tumor risk shared with GLP-1 class agents. ### What is the retatrutide dosage used in clinical trials? The Phase 2 trial used a gradual escalation: 2 mg for weeks 1-4, 4 mg for weeks 5-8, 8 mg for weeks 9-12, then up to 12 mg weekly thereafter. This titration schedule is designed to minimize gastrointestinal side effects while advancing to the highest studied dose. ### Is retatrutide legal to use? Retatrutide is not FDA-approved and has no approved indication in any country as of the time of writing. It exists only as an investigational compound in ongoing clinical trials. Obtaining or using retatrutide outside a supervised clinical trial is not sanctioned and carries significant regulatory and safety uncertainty. ### When will retatrutide be approved? Retatrutide is currently in Phase 3 clinical trials as of the latest available data. FDA approval, if granted, would typically follow successful Phase 3 completion and regulatory review, a process that generally takes several years. No official approval timeline has been announced by Eli Lilly. ## References 1. Jastreboff AM, Kaplan LM, Frias JP, et al.. "Triple-Hormone-Receptor Agonist Retatrutide for Obesity -- A Phase 2 Trial." *N Engl J Med*, 2023. PMID: 37366315. https://pubmed.ncbi.nlm.nih.gov/37366315/ 2. Rosenstock J, Frias JP, Jastreboff AM, et al.. "Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a randomised, double-blind, placebo and active-controlled, parallel-group, phase 2 trial conducted in the USA." *Lancet*, 2023. PMID: 37385280. https://pubmed.ncbi.nlm.nih.gov/37385280/ 3. Sanyal AJ, Bedossa P, Engel SS, et al.. "Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trial." *Nat Med*, 2024. PMID: 38858523. https://pubmed.ncbi.nlm.nih.gov/38858523/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Retatrutide is an investigational compound that has not been approved by the FDA or any regulatory authority. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/retatrutide --- # BPC-157 **BPC-157 (Body Protection Compound 157)** Category: Healing > Healing and Regenerative Peptide BPC-157 is a synthetic pentadecapeptide derived from a protective protein found in human gastric juice. Extensively studied in animal models, it demonstrates potent regenerative, anti-inflammatory, and neuroprotective properties across multiple tissue types. ## Key Facts - **Molecular weight:** 1419.5 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/9941957/property/MolecularFormula,MolecularWeight/JSON) - **Molecular formula:** C62H98N16O22 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/9941957/property/MolecularFormula,MolecularWeight/JSON) - **Sequence length:** 15 amino acids (sequence GEPPPGKPADDAGLV) (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/9941957/JSON?heading=Depositor-Supplied+Synonyms) - **Primary target:** Nitric oxide (NO) system, including eNOS-derived NO and VEGFR2 (vascular endothelial growth factor receptor 2) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC11859134/) - **Mechanism class:** Cytoprotective/organoprotective gastric pentadecapeptide; pro-angiogenic and regenerative agent acting via the NO system, VEGFR2, and FAK-paxillin / growth-factor pathways (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC11859134/) - **Half-life:** Short: ~15.2 min (IV, rats); <30 min (IM, rats); 5.27 +/- 2.25 min (IV, beagle dogs). Human half-life not established. (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC9794587/) - **Route of administration:** Subcutaneous or intramuscular injection; oral and intravenous routes also studied (oral under investigation) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC9794587/) - **Regulatory status:** Not approved by FDA or EMA for human use; investigational/research-use-only. Placed on FDA 503A Category 2 bulk-substances list in 2023 (significant safety concerns); no approved indication. (source: https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks) - **CAS number:** 137525-51-0 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/9941957/JSON?heading=CAS) ## Overview BPC-157 (Body Protection Compound 157) is a synthetic 15-amino-acid peptide fragment derived from a protein isolated in human gastric juice. It was first identified and studied by Croatian researcher Predrag Sikiric and his team, who have published extensively on its cytoprotective and organoprotective properties. The peptide is notable for its exceptional oral and systemic stability relative to most peptides. In animal studies, BPC-157 has consistently demonstrated the ability to accelerate tendon healing through tendon outgrowth, cell survival, and cell migration. It also appears to promote wound healing across multiple tissue types via angiogenesis and growth factor modulation. BPC-157 also shows profound effects on the gut-brain axis. Animal models show protection against NSAID-induced gut damage, promotion of intestinal anastomosis healing, and reversal of drug-induced dyskinesia and dopamine system disruption. These properties make it a subject of interest for inflammatory bowel conditions and neuroprotection research. It is important to note that no peer-reviewed human clinical trial data currently exists for BPC-157. All evidence for its benefits in humans is extrapolated from animal research and anecdotal reports from the research community. The peptide is not FDA-approved and is classified as a research compound only. ## Dosage Route: Subcutaneous or intramuscular injection; oral administration under investigation ### Schedule | Period | Dose | | --- | --- | | Standard research dose | 200-400 mcg (0.2-0.4 mg) per day | | Higher research dose | 500-1000 mcg (0.5-1.0 mg) per day | | Divided dosing | Split into two injections of 100-250 mcg, AM and PM | | Typical cycle length | 4-12 weeks on, 4 weeks off | ### Reconstitution - Vial size: 5 mg - Water volume: 2.5 mL - Concentration: 2 mg/mL (2000 mcg/mL) - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 200 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 200 mcg | 0.10 mL | 10 units | | 250 mcg | 0.125 mL | 12.5 units | | 400 mcg | 0.20 mL | 20 units | | 500 mcg | 0.25 mL | 25 units | ### Tips - Use bacteriostatic water (not sterile water) for reconstitution to extend shelf life to 30 days refrigerated - For localized injury (tendon, muscle, joint): inject subcutaneously near the site of injury - For systemic effects (gut, brain, general healing): inject subcutaneously in the abdomen - Administer consistently at the same times each day for stable plasma levels - Store lyophilized (unmixed) vials at -20C for up to 24 months; at room temperature for up to 3 months - Store reconstituted solution refrigerated at 2-8C and use within 30 days - Use a 29-31 gauge insulin syringe; inject slowly to minimize site discomfort ### Cycling - On period: 4-12 weeks of daily use - Off period: 4 weeks minimum off period - Notes: BPC-157 does not appear to cause hormonal suppression or significant receptor downregulation in animal studies, but research-use cycling protocols typically include off periods to allow assessment of baseline healing status and to reduce unknowns associated with prolonged use of an unstudied compound in humans. ### Local vs. Systemic Administration - Local: Inject subcutaneously directly adjacent to the injured area (e.g., near a damaged tendon, joint capsule, or muscle belly). This is the preferred method for localized tissue injuries where direct tissue exposure is desired. Some researchers use intramuscular injection near the injury site for deeper tissue access. - Systemic: Inject subcutaneously in the lower abdomen. This is the standard approach for gut-related applications (IBD, leaky gut, NSAID-induced damage), neurological effects, or when treating multiple sites simultaneously. Systemic delivery still appears effective for musculoskeletal healing based on animal studies. ## Side Effects ### Common - Injection site redness or mild swelling - Nausea (less common than with GLP-1 agents) - Dizziness or lightheadedness - Warm or flushed sensation post-injection - Vivid dreams (anecdotally reported) - Temporary fatigue ### Severe / Theoretical Risks - **Unknown long-term effects**: No human clinical trials exist. Long-term effects in humans are completely unknown. Use carries inherent unknown risk by definition. - **Angiogenesis promotion**: BPC-157 promotes new blood vessel formation. While beneficial for healing, this property theoretically raises concern in individuals with existing neoplastic (cancer) conditions, as new vasculature could support tumor growth. - **Drug interactions**: BPC-157 modulates dopamine, serotonin, and GABA systems in animal models. Interactions with psychotropic medications, opioids, and anticoagulants have not been formally studied in humans. - **Immune modulation**: Anti-inflammatory properties may mask symptoms of underlying infection or injury. Pain suppression could delay identification of serious conditions requiring medical intervention. ### Contraindications - Active cancer or history of malignancy (theoretical concern due to angiogenic properties) - Pregnancy or breastfeeding - Known hypersensitivity to BPC-157 or any excipient - Use in children or adolescents (no safety data) - Concurrent use with anticoagulants without medical supervision ## FAQ ### What is BPC-157? BPC-157 is a synthetic peptide of 15 amino acids derived from a protective protein found in human gastric juice. Researchers study it for potential regenerative effects on tendons, ligaments, muscles, and the gastrointestinal tract. It remains a research compound without FDA approval for human use. All evidence comes from animal studies. ### How does BPC-157 work? BPC-157 appears to work through multiple mechanisms: upregulation of growth hormone receptors in damaged tissue, promotion of angiogenesis through nitric oxide and VEGF pathways, modulation of the FAK-paxillin signaling pathway involved in tissue repair, and interaction with dopamine, serotonin, and GABA neurotransmitter systems in animal models. ### What does BPC-157 do for tendons and muscles? In animal studies, BPC-157 accelerates tendon-to-bone healing, reduces recovery time after muscle tears, and promotes ligament repair. It is thought to achieve this partly by increasing the density of growth hormone receptors at injury sites and by stimulating new blood vessel formation to improve nutrient delivery to damaged tissue. ### What are BPC-157 side effects? Reported side effects in the research and anecdotal community include injection site redness, mild nausea, dizziness, and temporary fatigue. More serious theoretical concerns include promotion of angiogenesis in individuals with existing cancer and unknown drug interactions with psychotropic medications or anticoagulants. No human clinical trial safety data exists. ### What is the BPC-157 dosage for research purposes? Research dosing protocols typically range from 200 to 400 mcg per day, often divided into two injections. Higher doses of 500 to 1000 mcg daily are also documented. For localized injury, injection near the site is common; for systemic effects, subcutaneous abdominal injection is standard. Typical cycles run 4 to 12 weeks. ### Can BPC-157 be taken orally? Oral administration of BPC-157 is under investigation. Unlike most peptides, BPC-157 demonstrates unusual stability in gastric acid, making oral delivery plausible for gut-related applications. However, oral bioavailability for systemic or musculoskeletal effects is not well established. Injectable forms are more commonly used in research protocols. ### Is BPC-157 legal? BPC-157 is not FDA-approved and is classified as a research compound. It is not a controlled substance in the United States, meaning possession is not a criminal offense, but it is not legal for human use. The regulatory status varies by country. Researchers and individuals use it at their own risk outside any clinical framework. ### How long does it take BPC-157 to work? Anecdotal reports from the research community describe noticeable changes in injury recovery within one to two weeks of consistent use. Animal studies show measurable tissue repair markers within days. The timeline depends heavily on the injury type, dose, administration method, and individual biology. No human clinical data confirms a defined onset period. ## References 1. Sikiric P, Hahm KB, Blagaic AB, et al.. "Stable Gastric Pentadecapeptide BPC 157, Robert's Stomach Cytoprotection/Adaptive Cytoprotection/Organoprotection, and Selye's Stress Coping Response: Progress, Achievements, and the Future." *Gut and Liver*, 2020. PMID: 31158953. https://pubmed.ncbi.nlm.nih.gov/31158953/ 2. Chang CH, Tsai WC, Lin MS, Hsu YH, Pang JH.. "The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration." *Journal of Applied Physiology (1985)*, 2011. PMID: 21030672. https://pubmed.ncbi.nlm.nih.gov/21030672/ 3. Seiwerth S, Milavic M, Vukojevic J, et al.. "Stable Gastric Pentadecapeptide BPC 157 and Wound Healing." *Frontiers in Pharmacology*, 2021. PMID: 34267654. https://pubmed.ncbi.nlm.nih.gov/34267654/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. BPC-157 is a research compound that has not been approved by the FDA or any regulatory authority for human use. No human clinical trial data exists for this compound. All referenced benefits are derived from animal studies and should not be interpreted as proven human effects. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/bpc-157 --- # Semaglutide **Semaglutide (GLP-1 Receptor Agonist)** Category: Weight Loss > GLP-1 Peptide for Weight Loss Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist that mimics the natural GLP-1 hormone, reducing appetite, slowing gastric emptying, and promoting significant weight loss. Marketed as Ozempic and Wegovy, it is one of the most clinically validated weight management peptides available. ## Key Facts - **Molecular weight:** 4114 g/mol (average; FDA label states 4113.58 g/mol) (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/56843331/property/MolecularFormula,MolecularWeight/JSON) - **Molecular formula:** C187H291N45O59 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/56843331/property/MolecularFormula,MolecularWeight/JSON) - **Sequence length:** 31 (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC8736331/) - **Primary target:** GLP-1 receptor (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC8736331/) - **Mechanism class:** GLP-1 receptor agonist (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=adec4fd2-6858-4c99-91d4-531f5f2a2d79) - **Half-life:** ~1 week (approximately 165 hours / 7 days) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC8736331/) - **Route of administration:** Subcutaneous injection, once weekly (also available orally as Rybelsus) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC8736331/) - **Regulatory status:** FDA approved: Ozempic for type 2 diabetes (Dec 2017); Wegovy for chronic weight management (June 2021) (source: https://www.drugs.com/history/wegovy.html) - **CAS number:** 910463-68-2 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/56843331/JSON?heading=CAS) ## Overview Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist originally developed for the treatment of type 2 diabetes. It mimics the natural GLP-1 hormone that is released in the gut in response to eating. By activating GLP-1 receptors, semaglutide increases insulin secretion, decreases glucagon secretion, and slows gastric emptying, which leads to reduced appetite and caloric intake. Semaglutide has gained significant attention for its effectiveness in promoting weight loss. In the STEP 1 trial, participants using once-weekly semaglutide 2.4 mg lost significantly more weight compared to placebo over 68 weeks. STEP 2 extended these findings to adults with type 2 diabetes, who also experienced clinically meaningful weight reduction. It is marketed under brand names such as Ozempic (for diabetes) and Wegovy (for weight management). Beyond glycemic control and weight loss, semaglutide has demonstrated cardiovascular benefit. The SUSTAIN-6 trial showed that semaglutide reduced the rate of major adverse cardiovascular events in patients with type 2 diabetes at high cardiovascular risk. This combination of metabolic and cardiovascular effects makes it one of the most clinically validated peptides in modern endocrinology. ## Dosage Route: Subcutaneous injection, once weekly ### Schedule | Period | Dose | | --- | --- | | Weeks 1-4 | 0.25 mg | | Weeks 5-8 | 0.5 mg | | Weeks 9-12 | 1.0 mg | | Weeks 13-16 | 1.7 mg | | Week 17+ | 2.4 mg (maintenance) | ### Reconstitution - Vial size: 5 mg - Water volume: 2 mL - Concentration: 2.5 mg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 0.25 mg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 0.25 mg | 0.1 mL | 10 units | | 0.5 mg | 0.2 mL | 20 units | | 1.0 mg | 0.4 mL | 40 units | | 1.7 mg | 0.68 mL | 68 units | | 2.4 mg | 0.96 mL | 96 units | ### Tips - Inject subcutaneously in the abdomen, thigh, or upper arm - Rotate injection sites to prevent lipodystrophy - Inject on the same day each week at any time of day - Store reconstituted solution in the refrigerator and use within 28 days ## Side Effects ### Common - Nausea (especially during dose escalation) - Vomiting - Diarrhea - Constipation - Abdominal pain - Headache - Fatigue - Injection site reactions ### Severe / Theoretical Risks - **Pancreatitis**: Inflammation of the pancreas; discontinue use if suspected. - **Gallbladder problems**: Including gallstones and cholecystitis. - **Kidney injury**: Usually related to dehydration from gastrointestinal side effects. - **Hypoglycemia**: Especially when combined with other diabetes medications. - **Allergic reactions**: Including anaphylaxis in rare cases. - **Thyroid C-cell tumors**: Semaglutide carries a boxed warning for risk of thyroid C-cell tumors based on animal studies; it is contraindicated in patients with a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). ### Contraindications - Personal or family history of medullary thyroid carcinoma - Multiple Endocrine Neoplasia syndrome type 2 (MEN 2) - Known hypersensitivity to semaglutide - Pregnancy or breastfeeding ## FAQ ### What is semaglutide? Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist that mimics the natural GLP-1 gut hormone. It suppresses appetite, slows gastric emptying, and increases insulin secretion in a glucose-dependent manner. Marketed as Ozempic for type 2 diabetes and Wegovy for chronic weight management, it is one of the most clinically validated weight-loss peptides available. ### How does semaglutide work for weight loss? Semaglutide binds GLP-1 receptors in the brain's appetite-regulating centers, reducing hunger and promoting satiety. It also slows gastric emptying, prolonging the feeling of fullness after meals. The result is a significant reduction in caloric intake. Clinical trials show average body weight reductions of approximately 15% over 68 weeks at the 2.4 mg weekly dose. ### What is the difference between Ozempic and Wegovy? Both Ozempic and Wegovy contain semaglutide, but they differ in approved indications and dosing. Ozempic (up to 2 mg) is approved for type 2 diabetes management. Wegovy (up to 2.4 mg) is FDA-approved specifically for chronic weight management in adults with obesity or overweight with a weight-related condition. ### What are semaglutide side effects? The most common side effects are gastrointestinal: nausea, vomiting, diarrhea, and constipation, most pronounced during dose escalation. Serious risks include pancreatitis, gallbladder problems, kidney injury from dehydration, and a boxed warning for thyroid C-cell tumors based on rodent studies. It is contraindicated in those with medullary thyroid carcinoma history. ### What is the semaglutide dosage for weight loss? The standard Wegovy titration schedule starts at 0.25 mg weekly for four weeks, escalating every four weeks through 0.5 mg, 1.0 mg, and 1.7 mg, reaching the 2.4 mg maintenance dose at week 17. This gradual escalation is designed to minimize nausea and other gastrointestinal side effects during the adjustment period. ### How long does it take for semaglutide to work? Most people experience reduced appetite within the first one to two weeks of use. Meaningful weight loss typically becomes apparent within four to eight weeks. Peak weight-loss results in clinical trials were observed at 68 weeks. The full benefit requires consistent long-term use; discontinuing semaglutide often leads to weight regain. ### Semaglutide vs tirzepatide: which is better for weight loss? Tirzepatide has shown greater average weight loss than semaglutide in clinical trials -- approximately 21% versus 15% body weight reduction. Tirzepatide's dual GIP and GLP-1 agonism provides a broader metabolic effect. However, direct head-to-head trials are limited, and individual responses vary. Both are established therapies with strong clinical evidence. ## References 1. Wilding JPH, Batterham RL, Calanna S, et al.. "Once-Weekly Semaglutide in Adults with Overweight or Obesity." *New England Journal of Medicine*, 2021. PMID: 33567185. https://pubmed.ncbi.nlm.nih.gov/33567185/ 2. Davies M, Færch L, Jeppesen OK, et al.. "Semaglutide 2·4 mg once a week in adults with overweight or obesity, and type 2 diabetes (STEP 2): a randomised, double-blind, double-dummy, placebo-controlled, phase 3 trial." *The Lancet*, 2021. PMID: 33667417. https://pubmed.ncbi.nlm.nih.gov/33667417/ 3. Marso SP, Bain SC, Consoli A, et al.. "Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes." *New England Journal of Medicine*, 2016. PMID: 27633186. https://pubmed.ncbi.nlm.nih.gov/27633186/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/semaglutide --- # Tirzepatide **Tirzepatide (Dual GIP/GLP-1 Receptor Agonist)** Category: Weight Loss > Dual Agonist Peptide for Weight Loss Tirzepatide is a first-in-class dual GIP and GLP-1 receptor agonist that provides complementary metabolic benefits beyond single-receptor agonists. In the SURMOUNT trials, participants lost up to 22.5% of body weight over 72 weeks, making it one of the most effective weight loss therapies available. ## Key Facts - **Molecular weight:** 4813.5 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/156588324/property/MolecularFormula,MolecularWeight/JSON) - **Molecular formula:** C225H348N48O68 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/156588324/property/MolecularFormula,MolecularWeight/JSON) - **Sequence length:** 39 amino acids (source: https://www.ncbi.nlm.nih.gov/books/NBK585056/) - **Primary target:** GIP receptor and GLP-1 receptor (higher affinity for GIP receptor) (source: https://www.ncbi.nlm.nih.gov/books/NBK585056/) - **Mechanism class:** Dual GIP/GLP-1 receptor agonist (source: https://www.ncbi.nlm.nih.gov/books/NBK585056/) - **Half-life:** approximately 5 days (source: https://www.ncbi.nlm.nih.gov/books/NBK585056/) - **Route of administration:** Subcutaneous injection, once weekly (source: https://www.ncbi.nlm.nih.gov/books/NBK585056/) - **Regulatory status:** FDA-approved: Mounjaro for type 2 diabetes (May 2022) and Zepbound for chronic weight management in obesity (Nov 2023); EMA-approved (Mounjaro, Sept 2022) (source: https://www.ncbi.nlm.nih.gov/books/NBK585056/) - **CAS number:** 2023788-19-2 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/156588324/JSON?heading=CAS) ## Overview Tirzepatide is a first-in-class dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist. Unlike semaglutide which targets only GLP-1 receptors, tirzepatide activates both GIP and GLP-1 receptors, providing a dual mechanism of action for blood sugar control and weight management. Originally developed for type 2 diabetes and marketed as Mounjaro, tirzepatide has demonstrated remarkable weight loss results in clinical trials. The SURMOUNT trials showed that participants lost up to 22.5% of their body weight over 72 weeks, making it one of the most effective weight loss therapies available. Tirzepatide works by enhancing insulin secretion in a glucose-dependent manner, suppressing glucagon, slowing gastric emptying, and reducing appetite through central nervous system pathways. The dual-agonist approach provides complementary metabolic benefits beyond what single-receptor agonists can achieve. ## Dosage Route: Subcutaneous injection, once weekly ### Schedule | Period | Dose | | --- | --- | | Weeks 1-4 | 2.5 mg | | Weeks 5-8 | 5.0 mg | | Weeks 9-12 | 7.5 mg | | Weeks 13-16 | 10.0 mg | | Weeks 17-20 | 12.5 mg | | Week 21+ | 15.0 mg (maximum maintenance) | ### Reconstitution - Vial size: 10 mg - Water volume: 2 mL - Concentration: 5 mg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 0.5 mg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 2.5 mg | 0.5 mL | 50 units | | 5.0 mg | 1.0 mL | 100 units | | 7.5 mg | 1.5 mL | Use two injections | | 10.0 mg | 2.0 mL | Use two injections | ### Tips - Inject subcutaneously in the abdomen, thigh, or upper arm - Rotate injection sites with each injection - Administer on the same day each week - Store reconstituted solution refrigerated and use within 28 days - Use a standard U-100 insulin syringe for accurate measurement ## Side Effects ### Common - Nausea (most common, especially during dose escalation) - Diarrhea - Decreased appetite - Vomiting - Constipation - Abdominal pain - Dyspepsia (indigestion) - Injection site reactions ### Severe / Theoretical Risks - **Pancreatitis**: Acute inflammation of the pancreas; seek medical attention for severe, persistent abdominal pain. - **Gallbladder disease**: Including gallstones and cholecystitis. - **Hypoglycemia**: Particularly when used with insulin or sulfonylureas. - **Kidney injury**: Often secondary to dehydration from gastrointestinal effects. - **Allergic reactions**: Including potential anaphylaxis. - **Thyroid C-cell tumors**: Boxed warning based on rodent studies; contraindicated in patients with personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). - **Gastroparesis**: Severe slowing of gastric emptying in some individuals. ### Contraindications - Personal or family history of medullary thyroid carcinoma - Multiple Endocrine Neoplasia syndrome type 2 (MEN 2) - Known hypersensitivity to tirzepatide - Pregnancy or breastfeeding - Severe gastrointestinal disease ## FAQ ### What is tirzepatide? Tirzepatide is a first-in-class dual GIP and GLP-1 receptor agonist developed by Eli Lilly. Marketed as Mounjaro for type 2 diabetes and Zepbound for obesity, it activates two complementary metabolic pathways simultaneously. SURMOUNT trial participants lost up to 22.5% of body weight over 72 weeks, making it one of the most effective weight loss therapies studied. ### How does tirzepatide work? Tirzepatide activates both GIP and GLP-1 receptors. GLP-1 agonism suppresses appetite and slows gastric emptying; GIP agonism improves insulin sensitivity and complements GLP-1's effects on adipose tissue. The dual mechanism produces greater weight loss and glycemic control than either pathway alone, which is reflected in tirzepatide's superior trial outcomes versus GLP-1 monotherapy. ### What are tirzepatide side effects? Common side effects include nausea, diarrhea, vomiting, constipation, and abdominal pain -- most prominent during dose escalation. Serious risks include pancreatitis, gallbladder disease, hypoglycemia when combined with insulin, and gastroparesis in some individuals. A boxed warning exists for thyroid C-cell tumors based on rodent studies. ### What is the tirzepatide dosage for weight loss? The titration schedule starts at 2.5 mg weekly for four weeks and increases every four weeks: 5 mg, 7.5 mg, 10 mg, 12.5 mg, reaching 15 mg weekly at week 21. This gradual escalation minimizes gastrointestinal side effects. The 15 mg weekly dose represents the maximum maintenance dose studied in the SURMOUNT trials. ### Tirzepatide vs semaglutide: which produces more weight loss? Tirzepatide outperformed semaglutide in clinical data, with SURMOUNT trials showing up to 22.5% body weight reduction versus approximately 15% for semaglutide's STEP trials. The addition of GIP receptor agonism likely accounts for the difference. Both are effective options, and individual response, tolerability, and access should guide the choice. ### How long does tirzepatide take to work? Appetite suppression often begins within the first week or two at the starting dose. Significant weight loss is typically visible by weeks eight to twelve. Maximum average weight loss in clinical trials was observed around week 72. Like semaglutide, tirzepatide's effects diminish after discontinuation, and long-term use is required to maintain results. ### Is tirzepatide FDA-approved? Yes. Tirzepatide is FDA-approved as Mounjaro for type 2 diabetes management and as Zepbound for chronic weight management in adults with obesity or overweight with a weight-related comorbidity. Research-grade tirzepatide without a prescription is used off-label, which carries different regulatory and safety considerations. ## References 1. Jastreboff AM, Aronne LJ, Ahmad NN, et al.. "Tirzepatide Once Weekly for the Treatment of Obesity." *N Engl J Med*, 2022. PMID: 35658024. https://pubmed.ncbi.nlm.nih.gov/35658024/ 2. Frias JP, Davies MJ, Rosenstock J, et al.. "Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes." *N Engl J Med*, 2021. PMID: 34170647. https://pubmed.ncbi.nlm.nih.gov/34170647/ 3. Willard FS, Douros JD, Gabe MB, et al.. "Tirzepatide is an imbalanced and biased dual GIP and GLP-1 receptor agonist." *JCI Insight*, 2020. PMID: 32730231. https://pubmed.ncbi.nlm.nih.gov/32730231/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/tirzepatide --- # AOD-9604 **AOD-9604 (hGH Fragment 176-191)** Category: Weight Loss > Modified Growth Hormone Fragment for Fat Loss AOD-9604 is a modified fragment of human growth hormone (amino acids 176-191) engineered to stimulate lipolysis and inhibit lipogenesis without affecting blood sugar or IGF-1. It is particularly effective at reducing abdominal fat. ## Key Facts - **Molecular weight:** 1815.1 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/71300630) - **Molecular formula:** C78H123N23O23S2 (source: https://pubchem.ncbi.nlm.nih.gov/compound/71300630) - **Sequence length:** 16 amino acids (hexadecapeptide; sequence YLRIVQCRSVEGSCGF = Tyr + hGH residues 177-191, with an intramolecular disulfide bond between the two cysteines) (source: https://www.jofem.org/index.php/jofem/article/view/157/194) - **Primary target:** No confirmed high-affinity receptor target; AOD9604 is not a high-affinity antagonist of hGH binding to the GH receptor. Proposed mechanism involves inhibition of lipoprotein lipase and upregulation of beta-3-adrenergic receptor (ADRB3) expression, but the primary molecular target remains undefined in the literature. (source: https://jofem.org/index.php/jofem/article/view/213/278) - **Mechanism class:** Lipolytic growth hormone C-terminal fragment (hGH 177-191 analog); stimulates lipolysis and inhibits lipogenesis without somatotropic, diabetogenic, or IGF-1-raising activity (source: https://jofem.org/index.php/jofem/article/view/213/278) - **Route of administration:** Subcutaneous injection in current practice/research use; original Metabolic Pharmaceuticals human clinical trials used intravenous infusion (METAOD001-002) and oral capsules/tablets (METAOD003-006) (source: https://www.jofem.org/index.php/jofem/article/view/157/194) - **Regulatory status:** Not FDA-approved for human therapeutic use for any indication; no NDA filed and no Phase III completed. Received conditional GRAS (Generally Recognized As Safe) determination for use as a food/dietary supplement ingredient. Clinical development for obesity was discontinued after Phase IIb (modest weight loss). Available only as a research/compounding substance. (source: https://jofem.org/index.php/jofem/article/view/213/278) - **CAS number:** 221231-10-3 (source: https://pubchem.ncbi.nlm.nih.gov/compound/71300630) ## Overview AOD-9604 (Advanced Obesity Drug) is a modified fragment of human growth hormone (hGH), specifically the amino acids 176-191 of the hGH polypeptide. It was developed to isolate the fat-burning properties of growth hormone without the adverse effects associated with full-length hGH, such as insulin resistance and increased IGF-1 levels. AOD-9604 works by mimicking the way natural growth hormone regulates fat metabolism. It stimulates lipolysis (the breakdown of fat) and inhibits lipogenesis (the formation of new fat). Unlike full hGH, AOD-9604 does not affect blood sugar levels or promote cell proliferation, making it a safer option for targeted fat reduction. Research has shown that AOD-9604 has a particularly strong effect on reducing abdominal fat. It enhances the body's ability to oxidize fat for energy without stimulating appetite or causing the muscle or bone growth effects of HGH. AOD-9604 does not have FDA approval for human use. ## Dosage Route: Subcutaneous injection, once daily ### Schedule | Period | Dose | | --- | --- | | Standard dose | 300 mcg daily | | Higher dose (advanced) | 500 mcg daily (as directed) | ### Reconstitution - Vial size: 5 mg (5000 mcg) - Water volume: 2 mL - Concentration: 2500 mcg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 250 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 250 mcg | 0.1 mL | 10 units | | 300 mcg | 0.12 mL | 12 units | | 500 mcg | 0.2 mL | 20 units | ### Tips - Inject subcutaneously in the abdomen for best results - Administer first thing in the morning on an empty stomach - Wait at least 30 minutes before eating after injection - Rotate injection sites to prevent irritation - Store reconstituted solution refrigerated and use within 28 days ## Side Effects ### Common - Headache - Injection site redness or swelling - Mild nausea - Stomach discomfort - Flu-like symptoms (rare, typically during initial use) ### Severe / Theoretical Risks - **Allergic reactions**: Swelling, difficulty breathing, or rash; discontinue immediately if these occur. - **Chest tightness**: Rare; discontinue use and consult a doctor. - **Hypoglycemia**: Very rare, as AOD-9604 does not significantly impact blood sugar. ### Contraindications - Known hypersensitivity to AOD-9604 or any component - Active cancer or history of cancer (as a precaution with any growth hormone fragment) - Pregnancy or breastfeeding - Children and adolescents (not studied in this population) ## FAQ ### What is AOD-9604? AOD-9604 is a modified fragment of human growth hormone, specifically amino acids 176-191. It was engineered to isolate growth hormone's fat-burning properties without increasing blood sugar, IGF-1, or promoting cell growth. AOD-9604 has not received FDA approval for human use. ### How does AOD-9604 work for fat loss? AOD-9604 stimulates lipolysis -- the breakdown of stored fat -- and inhibits lipogenesis, the formation of new fat cells. It mimics the way the C-terminus of natural growth hormone regulates fat metabolism. Unlike full-length hGH, it has no significant effect on blood sugar or insulin-like growth factor levels, making it a more targeted fat-reduction compound. ### What is the AOD-9604 dosage? Standard research dosing is 300 mcg daily via subcutaneous injection, administered in the morning on an empty stomach. Some protocols use higher doses of 500 mcg daily. A 30-minute fast after injection is recommended to avoid blunting the lipolytic effect. Injection into the abdominal area is the most commonly documented approach. ### What are AOD-9604 side effects? AOD-9604 is generally considered well-tolerated. Reported side effects include headache, mild nausea, stomach discomfort, injection site redness, and occasional flu-like symptoms during initial use. Serious adverse events are rare but include allergic reactions. As a precaution, it is not recommended for individuals with a history of cancer. ### Does AOD-9604 increase IGF-1 or affect hormones? No. Unlike full-length human growth hormone, AOD-9604 does not significantly raise IGF-1, blood glucose, or cortisol. It was specifically designed to isolate the fat-metabolizing region of hGH while leaving the growth-promoting and insulin-resistant effects behind. This profile is why it was studied as a safer alternative to hGH for fat loss. ### AOD-9604 vs HGH Fragment 176-191: are they the same? AOD-9604 and HGH Fragment 176-191 refer to the same region of the human growth hormone sequence but are not identical. AOD-9604 is a modified version with an additional tyrosine residue at the N-terminus, which enhances its stability and bioavailability. The terms are sometimes used interchangeably in research communities, though technically distinct. ## References 1. Ng FM, Sun J, Sharma L, et al.. "Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone." *Horm Res*, 2000. PMID: 11146367. https://pubmed.ncbi.nlm.nih.gov/11146367/ 2. Heffernan M, Summers RJ, Thorburn A, et al.. "The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out mice." *Endocrinology*, 2001. PMID: 11713213. https://pubmed.ncbi.nlm.nih.gov/11713213/ 3. Kwon DR, Park GY, Lee SC. "Effect of Intra-articular Injection of AOD9604 with or without Hyaluronic Acid in Rabbit Osteoarthritis Model." *Ann Clin Lab Sci*, 2015. PMID: 26275694. https://pubmed.ncbi.nlm.nih.gov/26275694/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/aod-9604 --- # Ipamorelin **Ipamorelin (Selective GHRP-5)** Category: Growth/Strength > Selective Growth Hormone Releasing Peptide for Strength Ipamorelin is a selective growth hormone releasing peptide (GHRP) that triggers the natural pulsatile release of GH without significantly increasing cortisol, prolactin, or appetite. It is widely considered one of the safest and most well-tolerated GH-releasing peptides, often combined with CJC-1295 for enhanced results. ## Key Facts - **Molecular weight:** 711.9 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/9831659) - **Molecular formula:** C38H49N9O5 (source: https://pubchem.ncbi.nlm.nih.gov/compound/9831659) - **Sequence length:** 5 amino acids (source: https://pubchem.ncbi.nlm.nih.gov/compound/9831659) - **Primary target:** Growth hormone secretagogue receptor (GHS-R1a / ghrelin receptor) (source: https://pubmed.ncbi.nlm.nih.gov/9849822/) - **Mechanism class:** Growth hormone secretagogue (selective GH-releasing peptide / ghrelin receptor agonist) (source: https://pubmed.ncbi.nlm.nih.gov/9849822/) - **Half-life:** ~2 hours (terminal, intravenous infusion in healthy volunteers) (source: https://pubmed.ncbi.nlm.nih.gov/10496658/) - **Route of administration:** Subcutaneous injection (research use); intravenous infusion in the human PK study (source: https://pubmed.ncbi.nlm.nih.gov/10496658/) - **Regulatory status:** Not FDA-approved; investigational / research-use-only (never reached Phase III; nominated but not approved for 503A compounding) (source: https://www.fda.gov/media/182088/download) - **CAS number:** 170851-70-4 (source: https://pubchem.ncbi.nlm.nih.gov/compound/9831659) ## Overview Ipamorelin is a selective growth hormone releasing peptide (GHRP) that stimulates the pituitary gland to produce and release growth hormone (GH). It is a pentapeptide (five amino acids) that acts as a ghrelin/growth hormone secretagogue receptor agonist, triggering the natural pulsatile release of growth hormone. What makes ipamorelin unique among growth hormone releasing peptides is its selectivity. Unlike other GHRPs such as GHRP-6 or GHRP-2, ipamorelin does not significantly increase cortisol, prolactin, or appetite. This selectivity makes it one of the safest and most well-tolerated growth hormone peptides available. Ipamorelin promotes lean muscle growth, enhances fat metabolism, improves recovery from exercise and injury, strengthens bones, and supports better sleep quality. It works synergistically with growth hormone releasing hormones (GHRH) like CJC-1295, and the two are often used together for enhanced results. The growth hormone release from ipamorelin follows a natural pulsatile pattern, which helps maintain the body's normal hormonal feedback mechanisms and reduces the risk of desensitization that can occur with continuous GH stimulation. ## Dosage Route: Subcutaneous injection, 2-3 times daily ### Schedule | Period | Dose | | --- | --- | | Standard | 200-300 mcg per injection, 2-3 times daily | | Beginner | 100-200 mcg per injection, 2 times daily | | Advanced | 300 mcg per injection, 3 times daily | ### Reconstitution - Vial size: 5 mg (5000 mcg) - Water volume: 2 mL - Concentration: 2500 mcg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 250 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 100 mcg | 0.04 mL | 4 units | | 200 mcg | 0.08 mL | 8 units | | 250 mcg | 0.1 mL | 10 units | | 300 mcg | 0.12 mL | 12 units | ### Tips - Inject subcutaneously in the abdomen, thigh, or upper arm - Do not eat for at least 30 minutes before and after injection (food, especially carbs and fats, can blunt GH release) - Rotate injection sites - Store reconstituted solution refrigerated and use within 28 days - Optimal timing: morning upon waking, post-workout, and 30-60 minutes before sleep ### Cycling - On period: 8-12 weeks - Off period: 4 weeks - Notes: Cycle to prevent receptor desensitization. Repeat as needed. ## Side Effects ### Common - Headache (most common, usually mild) - Injection site redness or irritation - Mild dizziness - Flushing - Water retention (mild) - Tingling or numbness in extremities ### Severe / Theoretical Risks - **Carpal tunnel syndrome**: From elevated GH levels; usually dose-dependent. - **Joint pain**: Particularly at higher doses. - **Insulin resistance**: With prolonged high-dose use. - **Allergic reactions**: Rare; discontinue if swelling or difficulty breathing occurs. ### Contraindications - Active cancer or history of cancer - Known hypersensitivity to ipamorelin - Pregnancy or breastfeeding - Diabetic retinopathy - Children and adolescents (unless under medical supervision for growth deficiency) ## FAQ ### What is ipamorelin? Ipamorelin is a selective growth hormone releasing peptide (GHRP) and ghrelin mimetic consisting of five amino acids. It stimulates the pituitary gland to release growth hormone in a pulsatile, physiologically normal pattern. Unlike other GHRPs, it does not significantly elevate cortisol, prolactin, or appetite, making it one of the most well-tolerated peptides in its class. ### How does ipamorelin work? Ipamorelin acts as an agonist at the ghrelin receptor (GHS-R1a) in the pituitary gland, triggering a natural pulse of growth hormone release. Its selectivity means it primarily activates the GH axis without stimulating other hormonal pathways like ACTH or prolactin. The pulsatile release pattern preserves the body's normal feedback mechanisms and reduces receptor desensitization. ### What are the benefits of ipamorelin? Research on ipamorelin points to benefits including increased lean muscle mass, reduced body fat, improved sleep quality, faster recovery from training and injury, stronger bones, and enhanced immune function. These effects are attributed to the elevated growth hormone and downstream IGF-1 it promotes. It is often combined with CJC-1295 for synergistic GH release. ### What is the ipamorelin dosage? Standard research dosing is 200 to 300 mcg per injection, taken two to three times daily. Beginner protocols start at 100 to 200 mcg twice daily. Optimal timing is morning upon waking, post-workout, and 30 to 60 minutes before sleep. Food intake -- especially carbohydrates and fats -- should be avoided 30 minutes before and after injection to maximize GH release. ### What are ipamorelin side effects? Common side effects include mild headache, flushing, light dizziness, water retention, and tingling in the extremities. These are generally dose-dependent and related to elevated growth hormone. At higher doses or with prolonged use, more serious effects may include carpal tunnel syndrome, joint pain, and insulin resistance. ### Ipamorelin vs CJC-1295: what is the difference? Ipamorelin is a growth hormone releasing peptide (GHRP) that works via the ghrelin receptor. CJC-1295 is a growth hormone releasing hormone (GHRH) analog that works via the GHRH receptor. They act through different mechanisms and are commonly combined because their pathways are complementary -- together, they produce significantly greater GH release than either alone. ### How long does a cycle of ipamorelin last? Typical research protocols run ipamorelin for eight to twelve weeks followed by a four-week off period. The off period helps prevent receptor desensitization and allows baseline hormonal function to be assessed. Many practitioners run it alongside CJC-1295 for the full cycle duration for a synergistic growth hormone response. ## References 1. Raun K, Hansen BS, Johansen NL, et al.. "Ipamorelin, the first selective growth hormone secretagogue [^1]." *Eur J Endocrinol*, 1998. PMID: 9849822. https://pubmed.ncbi.nlm.nih.gov/9849822/ 2. Johansen PB, Nowak J, Skjaerbaek C, et al.. "Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats." *Growth Horm IGF Res*, 1999. PMID: 10373343. https://pubmed.ncbi.nlm.nih.gov/10373343/ 3. Venkova K, Fraser G, Hoveyda HR, et al.. "Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus." *J Pharmacol Exp Ther*, 2009. PMID: 19289567. https://pubmed.ncbi.nlm.nih.gov/19289567/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/ipamorelin --- # Tesamorelin **Tesamorelin (GHRH Analog)** Category: Growth/Strength > FDA-Approved GHRH Analog for Visceral Fat Reduction Tesamorelin is a synthetic growth hormone-releasing hormone (GHRH) analog that is FDA-approved for reducing excess abdominal visceral fat. It stimulates the pituitary gland's own GH production through natural feedback mechanisms, and has also been studied for cognitive enhancement and neuroprotective properties. ## Key Facts - **Molecular weight:** 5135.9 (free base); PubChem computes 5136 (source: https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/022505Orig1s010lbl.pdf) - **Molecular formula:** C221H366N72O67S (free base; acetate salt is C221H366N72O67S x C2H4O2, x ~ 7) (source: https://pubchem.ncbi.nlm.nih.gov/compound/16137828) - **Sequence length:** 44 (source: https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/022505Orig1s010lbl.pdf) - **Primary target:** Growth hormone-releasing factor (GRF/GHRH) receptor on pituitary somatotroph cells (source: https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/022505Orig1s010lbl.pdf) - **Mechanism class:** Growth hormone-releasing hormone (GHRH/GRF) analog; growth hormone secretagogue (source: https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/022505Orig1s010lbl.pdf) - **Half-life:** 26 min (healthy subjects) and 38 min (HIV-infected patients) after subcutaneous dosing for 14 consecutive days; mean 8 min after a single 1.4 mg subcutaneous dose (source: https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/022505Orig1s010lbl.pdf) - **Route of administration:** Subcutaneous injection, once daily (source: https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/022505Orig1s010lbl.pdf) - **Regulatory status:** FDA-approved (Egrifta, NDA 022505, approved November 10, 2010) for the reduction of excess abdominal fat in HIV-infected patients with lipodystrophy; also marketed as Egrifta SV (source: https://www.accessdata.fda.gov/drugsatfda_docs/appletter/2010/022505s000ltr.pdf) - **CAS number:** 218949-48-5 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16137828) ## Overview Tesamorelin is a synthetic growth hormone-releasing hormone (GHRH) analog that stimulates the pituitary gland to produce and release growth hormone. It consists of the 44 amino acids of human GHRH with an added trans-3-hexenoic acid group, which enhances its stability and bioavailability. Tesamorelin is FDA-approved under the brand name Egrifta for the reduction of excess abdominal fat (lipodystrophy) in HIV-infected patients. It is the only GHRH analog that has received FDA approval specifically for reducing visceral adipose tissue (VAT), the deep abdominal fat that surrounds internal organs and is associated with increased cardiovascular risk. Beyond its approved use, tesamorelin has attracted interest for its potential benefits in improving body composition, enhancing cognitive function, and supporting overall metabolic health. Studies have shown that tesamorelin can significantly reduce visceral fat while preserving subcutaneous fat and lean muscle mass. It also demonstrates neuroprotective properties and has been studied for its potential to improve cognitive function in older adults and those at risk for Alzheimer's disease. Tesamorelin works by binding to GHRH receptors in the pituitary gland, triggering a natural pulsatile release of growth hormone. Unlike synthetic HGH, tesamorelin stimulates the body's own production of GH, which helps maintain normal feedback mechanisms. ## Dosage Route: Subcutaneous injection, once daily ### Schedule | Period | Dose | | --- | --- | | FDA-approved dose | 2 mg daily (ongoing as prescribed) | | Research dose | 1-2 mg daily for 8-12 week cycles | ### Reconstitution - Vial size: 2 mg - Water volume: 2 mL - Concentration: 1 mg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 100 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 1 mg | 1.0 mL | 100 units | | 2 mg | 2.0 mL | Use two injections | ### Tips - Inject subcutaneously in the abdomen - Administer once daily, preferably at bedtime or in the morning on an empty stomach - Rotate injection sites to prevent irritation - Do not inject into scar tissue, bruises, or the navel area - Store reconstituted solution refrigerated and use within 28 days ## Side Effects ### Common - Injection site reactions (redness, itching, swelling, pain) - Joint pain (arthralgia) - Muscle pain (myalgia) - Peripheral edema (swelling in hands/feet) - Paresthesia (tingling, numbness) - Nausea - Headache ### Severe / Theoretical Risks - **Fluid retention**: Can worsen pre-existing conditions like carpal tunnel syndrome. - **Elevated IGF-1 levels**: May increase cancer risk theoretically; monitoring is recommended. - **Glucose intolerance**: May impair glucose metabolism; monitor blood sugar. - **Hypersensitivity reactions**: Including rash, urticaria, and rare anaphylaxis. - **Pituitary suppression**: Potential with long-term use; cycling is recommended. ### Contraindications - Active malignancy (cancer) - Disruption of the hypothalamic-pituitary axis due to hypophysectomy, hypopituitarism, or pituitary tumor/surgery - Known hypersensitivity to tesamorelin or mannitol - Pregnancy (Category X -- known to cause fetal harm) - Breastfeeding ## FAQ ### What is tesamorelin? Tesamorelin is a synthetic growth hormone-releasing hormone (GHRH) analog consisting of 44 amino acids with an added trans-3-hexenoic acid group for enhanced stability. It is FDA-approved as Egrifta for reducing excess abdominal visceral fat in HIV-positive patients with lipodystrophy, making it the only GHRH analog with FDA approval for visceral fat reduction. ### How does tesamorelin work? Tesamorelin binds GHRH receptors in the anterior pituitary gland, stimulating a pulsatile, physiologically normal release of growth hormone. Unlike synthetic HGH injections, it works through the body's own GH production pathway, preserving normal hormonal feedback. The resulting GH elevation reduces visceral adipose tissue while largely sparing subcutaneous fat and lean muscle. ### Can tesamorelin reduce belly fat? Yes. Clinical trials supporting its FDA approval showed significant reductions in visceral adipose tissue (VAT) -- the deep abdominal fat surrounding internal organs -- in HIV patients with lipodystrophy. Off-label use for general visceral fat reduction is studied and documented, though approved only for the HIV lipodystrophy indication. ### Does tesamorelin improve cognitive function? Research beyond its approved use suggests tesamorelin may have neuroprotective benefits. Studies in older adults and those at risk for Alzheimer's disease have shown improvements in memory and cognitive measures. This has generated interest in tesamorelin as a potential cognitive health intervention, though these applications are investigational. ### What is the tesamorelin dosage? The FDA-approved dose is 2 mg daily via subcutaneous abdominal injection. Research protocols often use 1 to 2 mg daily in 8 to 12 week cycles. Injection is typically administered at bedtime or in the morning on an empty stomach. The 2 mg dose often requires two separate 1 mg injections, as single injections above 1 mL can be uncomfortable. ### What are tesamorelin side effects? Common side effects include injection site reactions, joint pain, muscle aches, peripheral edema, tingling, nausea, and headache. More serious concerns include glucose intolerance, elevated IGF-1 levels with theoretical cancer risk, fluid retention that may worsen carpal tunnel syndrome, and rare hypersensitivity reactions including anaphylaxis. ### Tesamorelin vs CJC-1295: what is the difference? Both are GHRH analogs that stimulate pituitary GH release, but they differ in structure and application. Tesamorelin is FDA-approved with a stronger clinical evidence base for visceral fat reduction and possible cognitive benefits. CJC-1295 is a research compound available in DAC and non-DAC forms with more flexibility in half-life and dosing frequency. ## References 1. Falutz J, Allas S, Blot K, et al.. "Metabolic effects of a growth hormone-releasing factor in patients with HIV." *N Engl J Med*, 2007. PMID: 18057338. https://pubmed.ncbi.nlm.nih.gov/18057338/ 2. Falutz J, Potvin D, Mamputu JC, et al.. "Effects of tesamorelin, a growth hormone-releasing factor, in HIV-infected patients with abdominal fat accumulation: a randomized placebo-controlled trial with a safety extension." *J Acquir Immune Defic Syndr*, 2010. PMID: 20101189. https://pubmed.ncbi.nlm.nih.gov/20101189/ 3. Baker LD, Barsness SM, Borber S, et al.. "Effects of growth hormone-releasing hormone on cognitive function in adults with mild cognitive impairment and healthy older adults: results of a controlled trial." *Arch Neurol*, 2012. PMID: 22869065. https://pubmed.ncbi.nlm.nih.gov/22869065/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/tesamorelin --- # TB-500 **TB-500 (Thymosin Beta-4 Synthetic)** Category: Healing > Thymosin Beta-4 Analog for Healing and Recovery TB-500 is a synthetic version of Thymosin Beta-4, a naturally occurring peptide central to tissue protection, regeneration, and remodeling. It promotes healing through actin upregulation, cell migration, angiogenesis, and anti-inflammatory action, and is widely used in recovery protocols, often stacked with BPC-157. ## Key Facts - **Molecular weight:** 4963 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/16132341) - **Molecular formula:** C212H350N56O78S (source: https://pubchem.ncbi.nlm.nih.gov/compound/16132341) - **Sequence length:** 43 amino acids (source: https://rest.uniprot.org/uniprotkb/P62328.txt) - **Primary target:** G-actin (monomeric actin) -- sequesters actin monomers, inhibiting polymerization (source: https://rest.uniprot.org/uniprotkb/P62328.txt) - **Mechanism class:** Actin-sequestering peptide (beta-thymosin family) (source: https://rest.uniprot.org/uniprotkb/P62328.txt) - **Half-life:** 0.95 to 2.1 hours (dose-dependent, single IV dose 42-1260 mg) (source: https://pubmed.ncbi.nlm.nih.gov/20536472/) - **Route of administration:** Subcutaneous or intramuscular injection (IV used in human clinical trials) (source: https://pubchem.ncbi.nlm.nih.gov/compound/16132341) - **Regulatory status:** Not FDA approved for any human indication; not added to FDA 503A compounding bulks list (April 2026); WADA-prohibited (S0 non-approved substances, banned in and out of competition); sold research-use-only (source: https://www.bscg.org/blogs/single/tb-500-status-risks-and-bans-in-sport-and-military) - **CAS number:** 77591-33-4 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16132341) ## Overview TB-500 is a synthetic version of Thymosin Beta-4 (TB4), a naturally occurring 43-amino acid peptide present in virtually all human and animal cells. Thymosin Beta-4 is one of the most abundant intracellular peptides and plays a central role in the protection, regeneration, and remodeling of injured or damaged tissues. TB-500 promotes healing through several key mechanisms: upregulation of actin (a cell-building protein essential for tissue repair), promotion of cell migration to injury sites, reduction of inflammation, stimulation of new blood vessel growth (angiogenesis), and regulation of wound healing processes. Its ability to promote cell migration is particularly significant, as it allows repair cells to travel through damaged tissue more efficiently. TB-500 has shown efficacy in healing a wide range of injuries including muscle tears, tendon injuries, ligament sprains, skin wounds, and even cardiac tissue damage. It has been extensively used in veterinary medicine, particularly in equine sports medicine, for decades before gaining popularity in human biohacking and sports recovery communities. TB-500 is often used in combination with BPC-157 for enhanced healing effects, as the two peptides work through complementary mechanisms. ## Dosage Route: Subcutaneous or intramuscular injection ### Schedule | Period | Dose | | --- | --- | | Loading phase | 2-2.5 mg twice weekly for 4-6 weeks | | Maintenance | 2 mg once weekly for 4-6 weeks | | Injury protocol | 2.5 mg twice weekly until healed | ### Reconstitution - Vial size: 5 mg - Water volume: 2 mL - Concentration: 2.5 mg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 0.25 mg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 2.0 mg | 0.8 mL | 80 units | | 2.5 mg | 1.0 mL | 100 units | ### Tips - TB-500 is systemically active, so injection site does not need to be near the injury - Subcutaneous injection in the abdomen is the most common method - Intramuscular injection near the injury site is also effective - Rotate injection sites - Store reconstituted solution refrigerated and use within 28 days ### Cycling - On period: 4-6 weeks loading + 4-6 weeks maintenance - Off period: 2-4 weeks - Notes: Often stacked with BPC-157 for synergistic healing effects. ## Side Effects ### Common - Injection site discomfort or redness - Temporary lethargy or tiredness - Head rush or lightheadedness (shortly after injection) - Mild nausea ### Severe / Theoretical Risks - **Allergic reactions**: Swelling, rash, or difficulty breathing; discontinue immediately. - **Theoretical cancer concern**: TB-500 promotes angiogenesis and cell migration, which could theoretically support tumor growth in individuals with existing cancer. No direct evidence supports this concern, but caution is warranted. - **Cardiovascular effects**: Thymosin Beta-4 has been found in cardiac tissue and may affect heart function at very high doses. ### Contraindications - Active cancer or history of cancer (precautionary due to cell proliferation and angiogenic properties) - Known hypersensitivity to TB-500 or Thymosin Beta-4 - Pregnancy or breastfeeding - Acute cardiac events (recent heart attack or stroke) ## FAQ ### What is TB-500? TB-500 is a synthetic version of Thymosin Beta-4, a naturally occurring 43-amino acid peptide found in virtually all human cells. It plays a central role in tissue protection, regeneration, and remodeling. TB-500 has been used extensively in veterinary medicine for decades and is now studied in human research for injury recovery and systemic healing applications. ### How does TB-500 work? TB-500 promotes healing through several mechanisms: upregulating actin, a protein essential for cell structure and movement; stimulating cell migration to injury sites; promoting new blood vessel growth (angiogenesis); and reducing inflammation. Its ability to enhance cell migration is particularly notable, allowing repair cells to reach and work within damaged tissue more efficiently. ### What injuries does TB-500 help with? Animal and veterinary research documents TB-500's effects on muscle tears, tendon injuries, ligament sprains, skin wounds, and cardiac tissue damage. It has a long track record in equine sports medicine for musculoskeletal injuries. Human application extrapolates from this body of evidence, as no clinical trials in humans have been completed. ### What is the TB-500 dosage? Standard research protocols use a loading phase of 2 to 2.5 mg twice weekly for four to six weeks, followed by a maintenance phase of 2 mg once weekly for another four to six weeks. Injury-specific protocols often use 2.5 mg twice weekly until recovery. TB-500 is systemically active, so injection site does not need to be near the injury. ### What are TB-500 side effects? Reported side effects include injection site discomfort, temporary lethargy, lightheadedness shortly after injection, and mild nausea. More serious theoretical concerns include promotion of angiogenesis in those with existing cancer, and potential cardiovascular effects at very high doses. Allergic reactions are possible as with any injectable peptide. ### TB-500 vs BPC-157: what is the difference? TB-500 and BPC-157 are complementary healing peptides that work through different mechanisms. TB-500 operates primarily through actin regulation and cell migration; BPC-157 works through growth hormone receptor upregulation and nitric oxide pathways. They are frequently stacked together in recovery protocols because their mechanisms synergize for enhanced tissue repair. ### How long does it take TB-500 to work? Veterinary literature documents measurable healing improvements in horses within the first two to four weeks of a loading protocol. Anecdotal reports from human users describe reduced inflammation and improved recovery within one to three weeks. The timeline varies considerably based on injury severity, tissue type, dosage, and individual healing capacity. ## References 1. Malinda KM, Sidhu GS, Mani H, et al.. "Thymosin beta4 accelerates wound healing [^1]." *J Invest Dermatol*, 1999. PMID: 10469335. https://pubmed.ncbi.nlm.nih.gov/10469335/ 2. Bock-Marquette I, Saxena A, White MD, et al.. "Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair [^2]." *Nature*, 2004. PMID: 15565145. https://pubmed.ncbi.nlm.nih.gov/15565145/ 3. Crockford D, Turjman N, Allan C, et al.. "Thymosin beta4: structure, function, and biological properties supporting current and future clinical applications." *Ann N Y Acad Sci*, 2010. PMID: 20536467. https://pubmed.ncbi.nlm.nih.gov/20536467/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. TB-500 has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/tb-500 --- # CJC-1295 **CJC-1295 (Synthetic GHRH Analog)** Category: Growth/Strength > GHRH Analog for Sustained Growth Hormone Release CJC-1295 is a synthetic GHRH analog available in two forms: with DAC (extended half-life of 6-8 days, dosed weekly) and without DAC (30-minute half-life, dosed 2-3 times daily). It increases lean muscle, reduces body fat, improves sleep and recovery, and is commonly combined with ipamorelin for synergistic GH release. ## Key Facts - **Molecular weight:** 3367.9 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/91976842) - **Molecular formula:** C152H252N44O42 (source: https://pubchem.ncbi.nlm.nih.gov/compound/91976842) - **Sequence length:** 29 amino acids (source: https://pubchem.ncbi.nlm.nih.gov/compound/91976842) - **Primary target:** Growth hormone-releasing hormone receptor (GHRH receptor / GRF receptor) on the anterior pituitary (source: https://pubmed.ncbi.nlm.nih.gov/15817669/) - **Mechanism class:** GHRH analog / growth hormone secretagogue (GHRH receptor agonist) (source: https://pubmed.ncbi.nlm.nih.gov/15817669/) - **Route of administration:** Subcutaneous injection (source: https://pubmed.ncbi.nlm.nih.gov/16352683/) - **Regulatory status:** Not FDA/EMA approved for human use; investigational only, clinical development abandoned during Phase II (trial subject death); research-use-only / not approved (source: https://www.aidsmap.com/news/jul-2006/lipodystrophy-study-halted-after-patient-death) ## Overview CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH) consisting of 29 amino acids. It was developed to stimulate the pituitary gland to produce and release growth hormone in a sustained manner. CJC-1295 is one of the most widely used peptides for increasing growth hormone levels and improving body composition, strength, and recovery. CJC-1295 with DAC (Drug Affinity Complex): The DAC modification allows the peptide to bind to albumin in the bloodstream, dramatically extending its half-life from minutes to approximately 6-8 days. This results in a sustained, continuous elevation of growth hormone levels and means less frequent dosing (1-2 times per week). CJC-1295 without DAC (also called Modified GRF 1-29 or Mod GRF): Without the DAC modification, this form has a shorter half-life of approximately 30 minutes. It produces a more natural pulsatile release of growth hormone and is typically dosed 2-3 times daily, often in combination with a GHRP like ipamorelin. CJC-1295 works by binding to GHRH receptors in the anterior pituitary gland, amplifying the natural growth hormone releasing signal. Benefits include increased lean muscle mass, reduced body fat, improved sleep quality, enhanced recovery, and stronger immune function. ## Dosage Route: Subcutaneous injection ### Schedule | Period | Dose | | --- | --- | | CJC-1295 with DAC (standard) | 2 mg once weekly | | CJC-1295 with DAC (conservative) | 1 mg twice weekly | | CJC-1295 without DAC (standard) | 100 mcg, 2-3 times daily | | CJC-1295 without DAC + Ipamorelin | 100 mcg CJC + 200-300 mcg Ipamorelin, 2-3 times daily | ### Reconstitution - Vial size: 2 mg - Water volume: 2 mL - Concentration: 1 mg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 100 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 100 mcg | 0.1 mL | 10 units | | 200 mcg | 0.2 mL | 20 units | | 1 mg | 1.0 mL | 100 units | | 2 mg | 2.0 mL | Use two injections | ### Tips - Inject subcutaneously in the abdomen, thigh, or upper arm - For the non-DAC version, avoid eating for 30 minutes before and after injection - Rotate injection sites - Store reconstituted solution refrigerated and use within 28 days - Optimal injection timing without DAC: morning upon waking, 20-30 minutes post-workout, and 30-60 minutes before sleep ### Cycling - On period: 8-12 weeks (with DAC) or 12-16 weeks (without DAC) - Off period: 4-8 weeks - Notes: CJC-1295 without DAC can be used continuously for 12-16 weeks. Often paired with Ipamorelin for the entire cycle. ## Side Effects ### Common - Injection site reactions (redness, swelling, irritation) - Water retention - Tingling or numbness in extremities - Headache - Flushing - Dizziness - Mild joint pain ### Severe / Theoretical Risks - **CJC-1295 with DAC: sustained GH elevation effects**: The sustained GH elevation can lead to more pronounced side effects including significant water retention, carpal tunnel syndrome, and potential glucose metabolism issues. - **Carpal tunnel syndrome**: From chronically elevated GH; typically dose-dependent. - **Insulin resistance**: With prolonged use at high doses. - **Joint pain**: Can become significant at higher doses. - **Pituitary desensitization**: Possible with long-term continuous use, especially the DAC version. - **Allergic reactions**: Rare but possible. ### Contraindications - Active cancer or history of cancer - Known hypersensitivity to CJC-1295 - Diabetic retinopathy - Pregnancy or breastfeeding - Pituitary disorders ## FAQ ### What is CJC-1295? CJC-1295 is a synthetic growth hormone-releasing hormone (GHRH) analog consisting of 29 amino acids. It stimulates the pituitary gland to produce and release growth hormone. It is available in two forms: with DAC (Drug Affinity Complex), which extends its half-life to 6 to 8 days for weekly dosing, and without DAC, which has a 30-minute half-life and is dosed multiple times daily. ### What is the difference between CJC-1295 with DAC and without DAC? CJC-1295 with DAC binds to albumin in the bloodstream, extending its half-life to approximately 6 to 8 days, allowing once or twice weekly dosing with sustained GH elevation. Without DAC, the half-life is about 30 minutes, producing a more natural pulsatile GH release. The non-DAC form is often preferred when combined with a GHRP like ipamorelin. ### What are the benefits of CJC-1295? CJC-1295 is associated with increased lean muscle mass, reduced body fat, improved sleep quality and depth, enhanced exercise recovery, stronger immune function, and improved bone density. These effects stem from the elevation in growth hormone and subsequent IGF-1. It is most commonly used for body composition and anti-aging protocols. ### What is the CJC-1295 dosage? For CJC-1295 with DAC, the typical dose is 2 mg once weekly or 1 mg twice weekly. For the non-DAC form, 100 mcg is dosed two to three times daily. A common stack is 100 mcg of CJC-1295 no-DAC combined with 200 to 300 mcg of ipamorelin per injection, taken two to three times daily at defined intervals throughout the day. ### What are CJC-1295 side effects? Common side effects include water retention, tingling or numbness in the extremities, headache, flushing, dizziness, and mild joint pain. These are typically dose-dependent. The DAC form can produce more pronounced effects due to sustained GH elevation. Serious risks include carpal tunnel syndrome, insulin resistance, and potential pituitary desensitization with prolonged use. ### CJC-1295 vs ipamorelin: which is better? CJC-1295 (GHRH analog) and ipamorelin (GHRP) work through entirely different receptors and are not competitors -- they are complementary. CJC-1295 amplifies the GHRH signal; ipamorelin triggers the ghrelin receptor. Used together, they produce synergistic GH release significantly greater than either alone. The combination is one of the most widely used GH peptide stacks. ### How long does a CJC-1295 cycle last? With DAC, cycles typically run 8 to 12 weeks with a 4 to 8 week break. Without DAC, cycles can extend to 12 to 16 weeks. The off period allows the pituitary to recover baseline responsiveness and prevents receptor downregulation. Many practitioners run both CJC-1295 no-DAC and ipamorelin together for the entire cycle duration. ## References 1. Teichman SL, Neale A, Lawrence B, et al.. "Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults." *J Clin Endocrinol Metab*, 2006. PMID: 16352683. https://pubmed.ncbi.nlm.nih.gov/16352683/ 2. Ionescu M, Frohman LA. "Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog." *J Clin Endocrinol Metab*, 2006. PMID: 17018654. https://pubmed.ncbi.nlm.nih.gov/17018654/ 3. Jette L, Leger R, Thibaudeau K, et al.. "Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats: identification of CJC-1295 as a long-lasting GRF analog." *Endocrinology*, 2005. PMID: 15817669. https://pubmed.ncbi.nlm.nih.gov/15817669/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. CJC-1295 has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/cjc-1295 --- # MOTS-C **MOTS-C (Mitochondrial Open Reading Frame of the 12S rRNA Type-C)** Category: Longevity > Mitochondrial Peptide for Exercise and Metabolic Health MOTS-C is a mitochondrial-derived peptide that acts as an exercise mimetic by activating AMPK, the master regulator of cellular energy balance. It improves insulin sensitivity, enhances fat metabolism, increases endurance, and protects against age-related metabolic decline. Levels naturally decrease with age. ## Key Facts - **Molecular weight:** 2174.6 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/146675088/property/MolecularFormula,MolecularWeight/JSON) - **Molecular formula:** C101H152N28O22S2 (source: https://pubchem.ncbi.nlm.nih.gov/compound/146675088) - **Sequence length:** 16 amino acids (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/146675088/synonyms/JSON) - **Primary target:** AMPK (AMP-activated protein kinase), activated via inhibition of the folate cycle and AICAR accumulation (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC9905433/) - **Mechanism class:** Mitochondrial-derived peptide / AMPK activator (indirect, via folate-AICAR pathway) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC9905433/) - **Regulatory status:** Not FDA approved; research-use-only / investigational. No active IND or approved indication. (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC9905433/) - **CAS number:** 1627580-64-6 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/146675088/synonyms/JSON) ## Overview MOTS-C (Mitochondrial Open Reading Frame of the 12S rRNA Type-C) is a mitochondrial-derived peptide consisting of 16 amino acids. It is encoded by the mitochondrial genome and plays a fundamental role in metabolic regulation, exercise physiology, and cellular energy production. MOTS-C was first identified in 2015 by researchers at the University of Southern California. MOTS-C is often referred to as an exercise mimetic because it activates many of the same metabolic pathways that are stimulated by physical exercise. It works primarily by activating AMPK (AMP-activated protein kinase), a master regulator of cellular energy balance. When activated, AMPK promotes glucose uptake, fatty acid oxidation, and mitochondrial biogenesis while inhibiting energy-consuming processes. Key benefits of MOTS-C include improved insulin sensitivity, enhanced fat metabolism, increased exercise capacity and endurance, promotion of metabolic homeostasis, protection against age-related metabolic decline, and potential longevity benefits. Research has shown that MOTS-C levels naturally decline with age, which may contribute to age-related metabolic dysfunction. MOTS-C has also shown promise in protecting against diet-induced obesity, improving glucose tolerance, and enhancing physical performance in preclinical studies. It is gaining popularity in the longevity and biohacking communities as a peptide that supports healthy aging at the cellular level. ## Dosage Route: Subcutaneous injection ### Schedule | Period | Dose | | --- | --- | | Standard | 5 mg, 3-5 times per week | | Conservative | 5 mg, 3 times per week | | Intensive | 10 mg, 3-5 times per week | ### Reconstitution - Vial size: 10 mg - Water volume: 2 mL - Concentration: 5 mg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 0.5 mg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 5 mg | 1.0 mL | 100 units | | 10 mg | 2.0 mL | Use two injections | ### Tips - Inject subcutaneously in the abdomen, thigh, or upper arm - Can be taken at any time of day; some prefer pre-workout for enhanced exercise performance - Rotate injection sites - Store reconstituted solution refrigerated and use within 28 days ### Cycling - On period: 4-8 weeks - Off period: 2-4 weeks - Notes: Some practitioners advocate for lower-dose, longer-term use with periodic breaks for longevity protocols. ## Side Effects ### Common - Injection site discomfort or redness - Mild nausea - Temporary flushing or warmth - Headache (uncommon) ### Severe / Theoretical Risks - **Hypoglycemia**: MOTS-C enhances glucose uptake and insulin sensitivity; individuals on diabetes medications should monitor blood sugar closely. - **Allergic reactions**: As with any injectable peptide. - **Unknown long-term effects**: MOTS-C was only discovered in 2015; long-term safety data in humans is still being established. ### Contraindications - Known hypersensitivity to MOTS-C - Pregnancy or breastfeeding - Type 1 diabetes (use with extreme caution due to glucose-lowering effects) - Active cancer (precautionary, as effects on tumor metabolism are unknown) - Individuals on insulin or sulfonylurea medications (risk of hypoglycemia) ## FAQ ### What is MOTS-C? MOTS-C (Mitochondrial Open Reading Frame of the 12S rRNA Type-C) is a 16-amino acid peptide encoded by the mitochondrial genome, first identified in 2015 at the University of Southern California. Unlike other peptides encoded in nuclear DNA, it originates from the mitochondria. It acts as a metabolic regulator and is often called an exercise mimetic because it activates pathways similar to physical exercise. ### How does MOTS-C work? MOTS-C primarily activates AMPK (AMP-activated protein kinase), the master regulator of cellular energy balance. AMPK activation promotes glucose uptake by muscle cells, stimulates fatty acid oxidation, encourages mitochondrial biogenesis, and suppresses energy-wasting pathways. MOTS-C also enters the cell nucleus under stress conditions, directly regulating gene expression related to metabolism and stress response. ### What are the benefits of MOTS-C? Research on MOTS-C documents improvements in insulin sensitivity, enhanced fat metabolism, increased exercise capacity and endurance, protection against diet-induced obesity, and metabolic homeostasis. It is also studied for anti-aging applications because MOTS-C levels naturally decline with age, and this decline may contribute to age-related metabolic dysfunction and reduced physical performance. ### What is the MOTS-C dosage? Research protocols most commonly use 5 mg injected subcutaneously three to five times per week. Conservative protocols start at 5 mg three times weekly; more intensive protocols use 10 mg three to five times weekly. Pre-workout administration is popular for those targeting performance enhancement, though the timing is flexible. Standard cycles run four to eight weeks. ### What are MOTS-C side effects? MOTS-C is generally considered well-tolerated in research contexts. Reported side effects include injection site discomfort, mild nausea, temporary flushing, and occasional headache. The primary serious concern is hypoglycemia, as MOTS-C enhances glucose uptake and insulin sensitivity. Individuals on diabetes medications or insulin should monitor blood glucose carefully. ### Does MOTS-C decline with age? Yes. Research has shown that circulating MOTS-C levels naturally decline with aging. This decline correlates with reduced metabolic efficiency, decreased insulin sensitivity, and diminished exercise capacity observed in older adults. Some longevity researchers hypothesize that restoring MOTS-C levels may slow aspects of metabolic aging, though human clinical data is still limited. ### Is MOTS-C an exercise mimetic? MOTS-C is frequently described as an exercise mimetic because it activates AMPK and several other metabolic pathways that are engaged during physical exercise. Animal studies show improved endurance, enhanced fat oxidation, and better glucose metabolism in MOTS-C-treated subjects. It does not replicate all benefits of exercise but does share key molecular signaling with exercise-induced adaptations. ## References 1. Lee C, Zeng J, Drew BG, et al.. "The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance." *Cell Metab*, 2015. PMID: 25738459. https://pubmed.ncbi.nlm.nih.gov/25738459/ 2. Kim KH, Son JM, Benayoun BA, et al.. "The Mitochondrial-Encoded Peptide MOTS-c Translocates to the Nucleus to Regulate Nuclear Gene Expression in Response to Metabolic Stress." *Cell Metab*, 2018. PMID: 29983246. https://pubmed.ncbi.nlm.nih.gov/29983246/ 3. Reynolds JC, Lai RW, Woodhead JS, et al.. "MOTS-c is an exercise-induced mitochondrial-encoded regulator of age-dependent physical decline and muscle homeostasis." *Nat Commun*, 2021. PMID: 33473109. https://pubmed.ncbi.nlm.nih.gov/33473109/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. MOTS-C has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/mots-c --- # ARA-290 **ARA-290 (Cibinetide)** Category: Healing > Tissue-Protective EPO Analog for Healing and Neuropathic Pain ARA-290, also known as cibinetide, is a synthetic 11-amino acid peptide derived from the tissue-protective domain of erythropoietin. It activates the innate repair receptor (IRR) in injured tissue, suppressing inflammation and preventing cell death, without stimulating red blood cell production. It holds FDA Orphan Drug status for neuropathic pain in sarcoidosis. ## Key Facts - **Molecular weight:** 1257.3 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/91810664) - **Molecular formula:** C51H84N16O21 (source: https://pubchem.ncbi.nlm.nih.gov/compound/91810664) - **Sequence length:** 11 amino acids (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/91810664/property/MolecularFormula,MolecularWeight,IUPACName,Title/JSON) - **Primary target:** Innate repair receptor (IRR), the EPOR/CD131 (beta-common receptor) heterocomplex (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC3563705/) - **Mechanism class:** Non-erythropoietic, tissue-protective erythropoietin-derived peptide; innate repair receptor (IRR) agonist (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC5638901) - **Half-life:** Short serum half-life of a few minutes (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC3563705/) - **Route of administration:** Subcutaneous injection (once daily in clinical trials); intravenous used in early pharmacokinetic studies (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC3563705/) - **Regulatory status:** Investigational; not FDA approved for any indication. Holds FDA Orphan Drug and Fast Track designation for neuropathic pain in sarcoidosis. Completed Phase 2 clinical development. (source: https://www.prnewswire.com/news-releases/araim-pharmaceuticals-cibinetide-ara-290-regenerates-small-nerve-fibers-and-improves-neuropathic-clinical-symptoms-in-the-orphan-disease-of-sarcoidosis-300452818.html) - **CAS number:** 1208243-50-8 (source: https://pubchem.ncbi.nlm.nih.gov/compound/91810664) ## Overview ARA-290, also known by its investigational name cibinetide, is a synthetic 11-amino acid peptide derived from the tissue-protective domain of erythropoietin (EPO). Unlike native EPO, ARA-290 was deliberately engineered to strip out erythropoietic activity entirely, leaving only the tissue-protective signaling intact. This means it does not stimulate red blood cell production and carries none of the cardiovascular risks associated with elevated hematocrit. The peptide's mechanism centers on the innate repair receptor (IRR), a heteromeric complex formed by the erythropoietin receptor (EPOR) and the beta-common receptor (betacR). This receptor complex is selectively upregulated in injured or inflamed tissue and is largely absent in healthy, uninjured cells. When ARA-290 binds to the IRR, it initiates anti-apoptotic signaling, suppresses local pro-inflammatory cytokine cascades, and inhibits death signals that would otherwise lead to cell loss. Clinical research has evaluated ARA-290 most extensively in sarcoidosis-associated small fiber neuropathy (SFN). A randomized, placebo-controlled trial demonstrated that 4 mg subcutaneous daily injections over 28 days increased corneal nerve fiber density and significantly reduced neuropathic pain scores. A parallel metabolic study found improvements in insulin sensitivity and HbA1c in patients with type 2 diabetes. The FDA granted ARA-290 Orphan Drug status for neuropathic pain in sarcoidosis. Preclinical research spans models of myocardial infarction, diabetic retinopathy, traumatic brain injury, burns, and shock-induced multi-organ failure. Human pharmacokinetic data shows a peak plasma concentration of roughly 3 ng/mL following a 4 mg subcutaneous dose, with a terminal half-life of approximately 20 minutes. ## Dosage Route: Subcutaneous injection, once daily ### Schedule | Period | Dose | | --- | --- | | Clinical trial standard (sarcoidosis) | 4 mg once daily for 28 days | | Research extension | 4 mg once daily for up to 12 weeks | ### Reconstitution - Vial size: 10 mg - Water volume: 2.5 mL - Concentration: 4 mg/mL - Per unit: Each 1.0 mL = 4 mg (target clinical dose) ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 4 mg | 1.0 mL | Full dose | | 2 mg | 0.5 mL | Half dose | | 1 mg | 0.25 mL | Quarter dose | ### Tips - Inject subcutaneously into the abdomen, thigh, or upper arm - Use an insulin syringe (29-31 gauge) - Rotate injection sites - Store reconstituted peptide refrigerated and use within 28 days - Sterile water may be used for single-use reconstitution instead of bacteriostatic water ## Side Effects ### Common - Mild injection site redness or swelling - Transient headache - Fatigue following first injections - Minor nausea ### Severe / Theoretical Risks - **Hypersensitivity reactions**: Rare but possible allergic responses including rash or urticaria; discontinue and seek care if systemic symptoms appear. - **Unknown long-term effects**: ARA-290 lacks long-duration human safety data beyond 12 weeks; prolonged use carries unquantified risk. - **Off-target receptor activation**: At high concentrations, partial binding to EPOR cannot be fully excluded, though no erythropoietic effects were observed in clinical trials at 4 mg/day. ### Contraindications - Active malignancy (EPO-family peptides may stimulate tumor microenvironments) - Pregnancy or breastfeeding (no safety data) - Known hypersensitivity to erythropoietin analogs - Concurrent use of anticoagulants (theoretical interaction with tissue-protective vascular pathways) ## FAQ ### What is ARA-290 and how does it work? ARA-290, also called cibinetide, is a synthetic 11-amino acid peptide derived from the tissue-protective domain of erythropoietin. It activates the innate repair receptor in injured tissue, suppressing inflammation and preventing cell death without stimulating red blood cell production or raising cardiovascular risk. ### What conditions is ARA-290 being studied for? ARA-290 has been most extensively studied for sarcoidosis-associated small fiber neuropathy, where clinical trials showed increased corneal nerve fiber density and reduced neuropathic pain. It also holds FDA Orphan Drug status for neuropathic pain in sarcoidosis and has preclinical data in diabetic retinopathy and traumatic brain injury. ### What is the standard dosage for ARA-290? In clinical trials, the standard dose was 4 mg subcutaneously once daily for 28 days. Research extensions used the same 4 mg daily dose for up to 12 weeks. The peptide is typically reconstituted to 4 mg/mL concentration using bacteriostatic water and injected with an insulin syringe. ### What are the side effects of ARA-290? Common side effects include mild injection site redness, transient headache, fatigue following initial injections, and minor nausea. Serious adverse events are rare but may include hypersensitivity reactions. ARA-290 lacks long-term safety data beyond 12 weeks of human use. ### Is ARA-290 FDA approved? ARA-290 is not FDA approved for any medical condition. However, it has received FDA Orphan Drug designation for neuropathic pain in sarcoidosis, which provides a pathway toward potential future approval. It is currently available only as a research compound. ### How does ARA-290 differ from erythropoietin (EPO)? ARA-290 was engineered to retain only the tissue-protective signaling of EPO while eliminating erythropoietic activity entirely. Unlike EPO, ARA-290 does not stimulate red blood cell production and carries none of the cardiovascular risks associated with elevated hematocrit that limit EPO use. ## References 1. Brines M, Patel NS, Villa P, et al.. "Nonerythropoietic, tissue-protective peptides derived from the tertiary structure of erythropoietin." *Proc Natl Acad Sci U S A*, 2008. PMID: 18676614. https://pubmed.ncbi.nlm.nih.gov/18676614/ 2. Brines M, Dunne AN, van Brederode JF, et al.. "ARA 290, a nonerythropoietic peptide engineered from erythropoietin, improves metabolic control and neuropathic symptoms in patients with type 2 diabetes." *Mol Med*, 2015. PMID: 25387363. https://pubmed.ncbi.nlm.nih.gov/25387363/ 3. Dahan A, Dunne A, Swartjes M, et al.. "ARA 290 improves symptoms in patients with sarcoidosis-associated small nerve fiber loss and increases corneal nerve fiber density." *Mol Med*, 2013. PMID: 24136731. https://pubmed.ncbi.nlm.nih.gov/24136731/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. ARA-290 has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/ara-290 --- # GHK-Cu **GHK-Cu (Glycyl-L-Histidyl-L-Lysine Copper Complex)** Category: Skin > Copper Tripeptide for Healing and Skin Regeneration GHK-Cu is a naturally occurring human tripeptide complexed with copper (II) ions, first identified in 1973. It stimulates collagen synthesis and tissue remodeling, promotes angiogenesis, suppresses inflammation, and modulates over 4,000 human genes. Plasma concentrations decline sharply with age. It has decades of safety data in cosmetic formulations and growing evidence for systemic injectable use. ## Key Facts - **Molecular weight:** 403.92 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/378611/property/MolecularWeight/JSON) - **Molecular formula:** C14H24CuN6O4 (source: https://pubchem.ncbi.nlm.nih.gov/compound/378611) - **Sequence length:** 3 (source: https://pubchem.ncbi.nlm.nih.gov/compound/378611) - **Primary target:** Cellular copper uptake / transport and broad human gene-expression regulation (no single named receptor); stimulates collagen, GAG, and growth-factor (VEGF, BDNF, BMP-2) synthesis and activates the proteasome system (source: https://pubmed.ncbi.nlm.nih.gov/29986520/) - **Mechanism class:** Copper-binding tripeptide / matricellular regenerative and protective agent (oligopeptide copper complex); not a receptor agonist (source: https://pubmed.ncbi.nlm.nih.gov/29986520/) - **Route of administration:** Topical application (cosmetic); subcutaneous injection (research/investigational) (source: https://clinicaltrials.gov/study/NCT07437586) - **Regulatory status:** Not FDA-approved as a drug. Registered with FDA as substance 'Prezatide copper' (UNII 6BJQ43T1I9); investigated as a wound-healing drug (Iamin) but never received FDA marketing approval. Topical 'Copper Tripeptide-1' is used as a non-drug cosmetic ingredient (no premarket FDA approval required). (source: https://precision.fda.gov/uniisearch/srs/unii/6BJQ43T1I9) - **CAS number:** 89030-95-5 (source: https://precision.fda.gov/uniisearch/srs/unii/6BJQ43T1I9) ## Overview GHK-Cu is a naturally occurring human tripeptide (glycyl-L-histidyl-L-lysine) complexed with copper (II) ions. The peptide was first identified in human plasma in 1973 by researcher Loren Pickart, who discovered that it had a profound stimulating effect on liver tissue repair. Since then, GHK has been found in multiple biological fluids, including saliva, urine, and wound fluid, and functions as a tissue remodeling signal throughout the body. Notably, plasma concentrations of GHK decline sharply with age: from approximately 200 ng/mL at age 20 to roughly 80 ng/mL by age 60. The mechanisms behind GHK-Cu are unusually broad. At the extracellular matrix level, the peptide simultaneously stimulates synthesis of collagen, glycosaminoglycans, dermatan sulfate, chondroitin sulfate, and the proteoglycan decorin, while also upregulating metalloproteinase activity to degrade and remove damaged collagen. This dual stimulation-and-cleanup action accelerates tissue remodeling. GHK-Cu also promotes angiogenesis, exerts anticoagulant and vasodilatory effects, and exhibits potent anti-inflammatory activity by reducing key cytokines such as IL-6. Large-scale gene expression analyses have identified over 4,000 human genes modulated by GHK, including genes involved in DNA repair, mitochondrial function, and the suppression of cancer-associated pathways. Clinical and human research on GHK-Cu spans both wound healing and cosmetic applications. In wound healing studies, collagen dressings incorporating GHK accelerated healing in healthy and diabetic rat models, with treated wounds showing 9-fold higher collagen content. In a human cosmetic trial, female volunteers applying GHK-Cu encapsulated in nano-lipid carriers twice daily for 8 weeks showed a 31.6% reduction in wrinkle volume compared to a Matrixyl 3000 control group. GHK-Cu occupies an unusual position in the peptide landscape: it has decades of safety data in cosmetic formulations (where it is used at concentrations up to 0.002%), a well-documented mechanism of action at nanomolar concentrations, and plausible systemic benefits from injectable forms. It remains unapproved by the FDA for any therapeutic indication but is widely used in cosmetic products under established safety parameters. ## Dosage Route: Subcutaneous injection or topical application ### Schedule | Period | Dose | | --- | --- | | Systemic research (SC) | 1-2 mg daily or 5 times per week | | Localized injection | 0.5-1 mg, 3 times per week (near target tissue) | | Topical cosmetic | 0.5-5% solution, 1-2 times daily | ### Reconstitution - Vial size: 50 mg - Water volume: 5 mL - Concentration: 10 mg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 1 mg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 0.5 mg | 0.05 mL | 5 units | | 1 mg | 0.10 mL | 10 units | | 2 mg | 0.20 mL | 20 units | ### Tips - Use a 29-31 gauge insulin syringe - Inject subcutaneously into the target region or abdominal fat for systemic use - Rotate injection sites daily - Store refrigerated and use reconstituted solution within 28 days - For topical use, apply to cleansed skin and allow to absorb before applying other products ### Local vs. Systemic Administration - Local: Subcutaneous injection near target tissue (e.g., near a wound or scar) at 0.5-1 mg, 3 times per week - Systemic: Subcutaneous injection in the abdomen at 1-2 mg daily or 5 times per week for whole-body skin and tissue benefits ## Side Effects ### Common - Injection site redness or bruising - Mild skin flushing after injection - Temporary darkening of skin at injection site (copper deposition, resolves with time) - Itching at application site with topical formulations ### Severe / Theoretical Risks - **Copper toxicity at excessive doses**: GHK-Cu delivers bioavailable copper; systemic copper overload (Wilson's disease pathway) is a theoretical risk at very high or chronic doses well above research protocols. - **Pro-oxidant effects at high concentration**: Copper can switch from antioxidant to pro-oxidant behavior at supraphysiological concentrations, potentially increasing oxidative stress rather than reducing it. - **Inadequate long-term injectable safety data**: Systemic injectable use lacks the same long-term human safety track record as topical use. ### Contraindications - Wilson's disease or other copper metabolism disorders - Active malignancy (GHK modulates genes in cancer-associated pathways; net effect on tumor growth is unclear) - Pregnancy or breastfeeding - Concurrent use of copper chelation therapy ## FAQ ### What is GHK-Cu and what does it do? GHK-Cu is a naturally occurring human tripeptide complexed with copper ions, first identified in 1973. It stimulates collagen synthesis, promotes angiogenesis, suppresses inflammation, and modulates over 4,000 human genes. Plasma levels decline sharply with age, from 200 ng/mL at age 20 to roughly 80 ng/mL by age 60. ### Does GHK-Cu really help with wrinkles and skin aging? Clinical evidence supports skin benefits. A human trial showed GHK-Cu encapsulated in nano-lipid carriers produced a 31.6% reduction in wrinkle volume over 8 weeks compared to a Matrixyl 3000 control. It works by simultaneously stimulating new collagen synthesis and breaking down damaged collagen through metalloproteinase activity. ### How do you use GHK-Cu for skin rejuvenation? GHK-Cu can be used topically at 0.5 to 5% concentration applied once or twice daily, or injected subcutaneously at 1 to 2 mg daily for systemic benefits. For localized healing near wounds or scars, 0.5 to 1 mg is injected near target tissue three times per week. ### What are GHK-Cu side effects? Common side effects include injection site redness or bruising, mild skin flushing, temporary darkening at injection sites from copper deposition, and itching with topical formulations. Excessive doses carry theoretical risk of copper toxicity, and systemic injectable use lacks the long-term safety data of topical products. ### Is GHK-Cu safe for people with Wilson's disease? No. GHK-Cu delivers bioavailable copper and is contraindicated for individuals with Wilson's disease or other copper metabolism disorders. People on copper chelation therapy should also avoid GHK-Cu, as it would directly counteract the purpose of chelation treatment. ### Can GHK-Cu help with wound healing? Research supports wound healing benefits. In animal studies, collagen dressings incorporating GHK accelerated healing with treated wounds showing 9-fold higher collagen content. The peptide promotes angiogenesis, reduces inflammatory cytokines like IL-6, and stimulates tissue remodeling at nanomolar concentrations. ## References 1. Pickart L, Margolina A. "Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data." *Int J Mol Sci*, 2018. PMID: 29986520. https://pubmed.ncbi.nlm.nih.gov/29986520/ 2. Pickart L, Vasquez-Soltero JM, Margolina A. "The human tripeptide GHK-Cu in prevention of oxidative stress and degenerative conditions of aging: implications for cognitive health." *Oxid Med Cell Longev*, 2012. PMID: 22666519. https://pubmed.ncbi.nlm.nih.gov/22666519/ 3. Pickart L, Vasquez-Soltero JM, Margolina A. "GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration." *Biomed Res Int*, 2015. PMID: 26236730. https://pubmed.ncbi.nlm.nih.gov/26236730/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. GHK-Cu has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/ghk-cu --- # KPV **KPV (Lys-Pro-Val)** Category: Inflammation > Targeted Anti-Inflammatory Tripeptide for Gut and Systemic Use KPV is a tripeptide (Lysine-Proline-Valine) representing the C-terminal fragment of alpha-MSH. It binds melanocortin receptors MC1R and MC3R to suppress NF-kappaB and MAP kinase inflammatory signaling, reducing pro-inflammatory cytokines including TNF-alpha, IL-1beta, IL-6, and IL-8. Its small molecular weight enables oral bioavailability for gut indications via the intestinal PepT1 transporter, and it has demonstrated efficacy in murine colitis models. ## Key Facts - **Molecular weight:** 342.43 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/125672) - **Molecular formula:** C16H30N4O4 (source: https://pubchem.ncbi.nlm.nih.gov/compound/125672) - **Sequence length:** 3 amino acids (Lys-Pro-Val) (source: https://pubchem.ncbi.nlm.nih.gov/compound/125672) - **Primary target:** Intestinal peptide transporter PepT1 (SLC15A1); intracellular NF-kappaB and MAPK inflammatory signaling. (Melanocortin receptors MC1R/MC3R implicated in some non-gut contexts but ruled out as mediator in intestinal/immune cells.) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC2431115/) - **Mechanism class:** Anti-inflammatory alpha-MSH(11-13) C-terminal tripeptide; acts via PepT1-mediated cellular uptake to suppress NF-kappaB and MAPK signaling and pro-inflammatory cytokines (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC2431115/) - **Route of administration:** Oral (gut inflammation), subcutaneous injection (systemic), or topical (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC2431115/) - **Regulatory status:** Not FDA-approved for any indication; research-use-only. Under FDA evaluation for the Section 503A compounding bulk drug substances list (Pharmacy Compounding Advisory Committee meeting July 23-24, 2026, evaluating KPV acetate / KPV free base). (source: https://www.fda.gov/advisory-committees/advisory-committee-calendar/july-23-24-2026-meeting-pharmacy-compounding-advisory-committee-07232026) - **CAS number:** 67727-97-3 (source: https://pubchem.ncbi.nlm.nih.gov/compound/125672) ## Overview KPV is a tripeptide consisting of the amino acids Lysine-Proline-Valine. It represents the C-terminal fragment of alpha-melanocyte stimulating hormone (alpha-MSH), a 13-amino acid peptide produced in the pituitary gland that plays a central role in immune regulation, inflammation, and pigmentation. Researchers identified that the last three amino acids of alpha-MSH retain its powerful anti-inflammatory signaling capacity while eliminating the melanogenic effects of the full peptide. This makes KPV a more targeted anti-inflammatory agent than its parent molecule, with a favorable size profile for tissue penetration and oral bioavailability. KPV's anti-inflammatory mechanism operates primarily through two interacting pathways. First, the peptide binds to melanocortin receptors MC1R and MC3R, which are expressed on immune cells including macrophages, neutrophils, and intestinal epithelial cells. Receptor activation initiates downstream signaling that suppresses NF-kappaB, the master transcription factor driving the expression of most pro-inflammatory cytokines. Second, KPV directly inhibits MAP kinase inflammatory signaling. The combined effect is a broad reduction in cytokine output, including TNF-alpha, IL-1beta, IL-6, and IL-8, all of which are central mediators of both acute and chronic inflammatory states. Research published in Gastroenterology (PMC2431115) demonstrated that nanomolar concentrations of KPV reduced NF-kappaB activation and inflammatory cytokine secretion in intestinal epithelial cells through the intestinal peptide transporter PepT1, which actively shuttles KPV into cells expressing this transporter. The gut-specific research on KPV is particularly compelling. Studies using murine models of inflammatory bowel disease found that orally administered KPV significantly reduced colitis severity in both dextran sodium sulfate (DSS) and trinitrobenzene sulfonic acid (TNBS) models. Treated animals showed decreased colonic myeloperoxidase (MPO) activity (a marker of neutrophil infiltration), reduced histological inflammation scores, lower body weight loss, and lower levels of pro-inflammatory cytokine mRNA compared to controls. A follow-up study published in the Journal of Controlled Release (PMC5498804) demonstrated that delivering KPV via hyaluronic acid nanoparticles improved colonic targeting, dramatically reducing the dose required for therapeutic effect. KPV also strengthens epithelial tight junction integrity, which is relevant to leaky gut conditions where barrier dysfunction amplifies inflammatory signaling. Beyond gut health, KPV has been studied in skin inflammation contexts. Its melanocortin receptor binding makes it relevant to inflammatory skin conditions such as psoriasis and atopic dermatitis, and animal studies have demonstrated reductions in skin inflammatory markers following topical and systemic KPV administration. The peptide's small size (molecular weight approximately 340 daltons) allows for oral administration with some preserved activity, which is unusual for peptides and represents a practical advantage for gastrointestinal indications. ## Dosage Route: Oral (gut inflammation), subcutaneous injection (systemic), or topical ### Schedule | Period | Dose | | --- | --- | | Oral (gut inflammation) | 200-500 mcg, 1-2x daily on empty stomach | | Subcutaneous (systemic) | 500 mcg - 1 mg, daily | | Topical | 1-5% formulation, 2x daily | ### Reconstitution - Vial size: 10 mg - Water volume: 10 mL bacteriostatic water - Concentration: 1 mg/mL (1,000 mcg/mL) - Per unit: Each 0.5 mL = 500 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 200 mcg | 0.20 mL | Oral or SC | | 500 mcg | 0.50 mL | Oral or SC | | 1,000 mcg | 1.00 mL | SC | ### Tips - For oral dosing, draw the appropriate volume and swallow or mix into a small amount of water - For subcutaneous injection, use a 29-31 gauge insulin syringe into the abdomen - Store reconstituted solution refrigerated and use within 28 days - Oral onset for gut effects is typically 1-2 weeks; gradual improvement may continue over 4-8 weeks - No official human dosing guidelines exist; protocols are extrapolated from animal research ### Local vs. Systemic Administration - Local: Oral dosing targets gut epithelium via PepT1 transporter; best for IBD and gut permeability. - Systemic: Subcutaneous injection provides broader distribution for joint or systemic inflammatory conditions. ## Side Effects ### Common - Mild nausea, especially with oral administration on an empty stomach - Injection site redness or swelling (subcutaneous use) - Temporary fatigue during initial days of use - Diarrhea or loose stools (possible transient effect as gut inflammation resolves) ### Severe / Theoretical Risks - **Immunosuppression risk at high doses**: Broad cytokine suppression, while beneficial in inflammatory conditions, may reduce immune surveillance in infectious or malignant contexts; dose titration is important. - **Melanocortin receptor interactions**: KPV binds melanocortin receptors; high doses or prolonged use may theoretically affect appetite regulation (MC3R/MC4R are involved in satiety) or pigmentation at supraphysiological exposures. - **No long-term human safety data**: All evidence is from preclinical animal studies or extrapolation; no controlled long-term human trials have been published. ### Contraindications - Active infection (anti-cytokine activity may impair pathogen clearance) - Active malignancy (cytokine suppression may blunt anti-tumor immune surveillance) - Pregnancy or breastfeeding - Immunocompromised states (HIV, post-transplant immunosuppression) ## FAQ ### What is KPV peptide and how does it work? KPV is a tripeptide (Lysine-Proline-Valine) derived from the C-terminal fragment of alpha-MSH. It binds melanocortin receptors MC1R and MC3R to suppress NF-kappaB inflammatory signaling, reducing pro-inflammatory cytokines including TNF-alpha, IL-1beta, IL-6, and IL-8 without causing skin pigmentation changes. ### Can KPV be taken orally for gut inflammation? Yes. Unlike most peptides, KPV's small molecular weight of approximately 340 daltons enables oral bioavailability through the intestinal PepT1 transporter. Studies in murine colitis models showed orally administered KPV significantly reduced colitis severity. Oral doses of 200 to 500 mcg are taken on an empty stomach. ### What conditions is KPV used for? KPV is primarily studied for inflammatory bowel disease, gut permeability issues, and systemic inflammatory conditions. Research shows it reduces colonic inflammation, strengthens epithelial tight junctions, and decreases neutrophil infiltration. It is also studied for inflammatory skin conditions like psoriasis and atopic dermatitis. ### What are KPV peptide side effects? Common side effects include mild nausea with oral use, injection site reactions with subcutaneous administration, temporary fatigue during initial days, and transient diarrhea as gut inflammation resolves. High doses may cause immunosuppression and could theoretically affect appetite regulation through melanocortin receptor binding. ### How long does KPV take to work for gut health? Oral onset for gut effects is typically one to two weeks, with gradual improvement continuing over four to eight weeks. For subcutaneous injection targeting systemic inflammation, effects may be noticed sooner. No official human dosing guidelines exist, and protocols are extrapolated from animal research. ### Who should not use KPV? KPV is contraindicated for people with active infections, active malignancy, immunocompromised states, and during pregnancy or breastfeeding. Its broad cytokine suppression, while beneficial for inflammation, may reduce immune surveillance against pathogens and tumor cells at higher doses. ## References 1. Dalmasso G, Charrier-Hisamuddin L, Nguyen HT, et al.. "PepT1-mediated tripeptide KPV uptake reduces intestinal inflammation." *Gastroenterology*, 2008. PMID: 18061177. https://pubmed.ncbi.nlm.nih.gov/18061177/ 2. Brzoska T, Luger TA, Maaser C, et al.. "Alpha-melanocyte-stimulating hormone and related tripeptides: biochemistry, antiinflammatory and protective effects in vitro and in vivo, and future perspectives for the treatment of immune-mediated inflammatory diseases." *Endocr Rev*, 2008. PMID: 18612139. https://pubmed.ncbi.nlm.nih.gov/18612139/ 3. Getting SJ, Christian HC, Lam CW, et al.. "Dissection of the anti-inflammatory effect of the core and C-terminal (KPV) alpha-melanocyte-stimulating hormone peptides." *J Pharmacol Exp Ther*, 2003. PMID: 12750433. https://pubmed.ncbi.nlm.nih.gov/12750433/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. KPV has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/kpv --- # LL-37 **LL-37 (Human Cathelicidin hCAP18 Fragment)** Category: Immune > Broad-Spectrum Antimicrobial and Immune Modulator LL-37 is the only cathelicidin antimicrobial peptide expressed in humans, derived from hCAP18 cleavage in neutrophils and epithelial cells. Its 37-amino acid helical structure disrupts bacterial cell membranes through pore formation, providing broad-spectrum activity against Gram-positive, Gram-negative, and drug-resistant organisms including MRSA. Beyond direct antimicrobial action, LL-37 modulates immune responses, promotes wound healing, neutralizes LPS, and has been studied as a potential protective factor against septic inflammatory cascades. ## Key Facts - **Molecular weight:** 4493 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/16198951) - **Molecular formula:** C205H340N60O53 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16198951) - **Sequence length:** 37 amino acids (source: https://rest.uniprot.org/uniprotkb/P49913.txt) - **Primary target:** Anionic bacterial cell membranes (phospholipid bilayer disruption); host-cell receptors FPR2/FPRL1 and P2X7 for immunomodulatory signaling (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC4505952/) - **Mechanism class:** Cationic host-defense (antimicrobial) peptide; membrane-disrupting cathelicidin with immunomodulatory activity (source: https://rest.uniprot.org/uniprotkb/P49913.txt) - **Route of administration:** Subcutaneous injection (research) or topical application (wound-healing trials); no approved human route (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC11762488/) - **Regulatory status:** Not FDA-approved for any indication; investigational / research-use-only. Early-phase human trials only (e.g., a Phase II topical wound-healing RCT). No EMA/FDA approval as of 2026. (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC11762488/) - **CAS number:** 154947-66-7 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16198951) ## Overview LL-37 is the only member of the cathelicidin family of antimicrobial peptides expressed in humans. Its name reflects its structure: 37 amino acids beginning with two leucine residues at the N-terminus. LL-37 is derived from the precursor protein hCAP18 (human cationic antimicrobial protein of 18 kDa), which is stored in the secondary granules of neutrophils and in the granules of macrophages. Upon activation by infection, tissue injury, or inflammatory stimuli, enzymes including neutrophil elastase and serine proteinase 3 cleave hCAP18 to release the active LL-37 peptide into the surrounding tissue and bloodstream. LL-37 is also produced by epithelial cells in the skin, lungs, gut, and urogenital tract as a first-line defense against pathogen invasion. LL-37's primary antimicrobial mechanism involves its net positive charge of +6, which allows electrostatic attraction to the negatively charged phospholipid membranes of bacteria. Upon membrane contact, LL-37 adopts a helical conformation and inserts into the lipid bilayer, forming transmembrane pores or disrupting membrane integrity through a carpet-like mechanism, leading to bacterial cell lysis. Structural research published in Scientific Reports documented that LL-37 forms a narrow tetrameric channel with a charged core when interacting with bacterial cell wall mimics. This membrane-disrupting mechanism is broadly effective against Gram-positive bacteria (including Staphylococcus aureus and Enterococcus), Gram-negative bacteria (including Pseudomonas aeruginosa and Escherichia coli), and even some drug-resistant organisms such as MRSA and vancomycin-resistant Enterococcus (VRE). Beyond direct killing of pathogens, LL-37 is an immunomodulatory molecule with complex bi-directional effects. It can both amplify and resolve inflammatory responses depending on context. LL-37 promotes neutrophil and macrophage recruitment, enhances phagocytosis, triggers dendritic cell maturation (contributing to adaptive immune priming), and stimulates angiogenesis and wound healing. At the same time, LL-37 has been shown to neutralize bacterial lipopolysaccharide (LPS), reducing the runaway inflammatory cascade of septic shock. Research during the COVID-19 pandemic prompted interest in LL-37 as a potential protective factor, with a Frontiers in Immunology review proposing that adequate LL-37 levels might reduce the severity of cytokine storm and microthrombosis through its LPS-neutralizing and immunomodulatory properties. Vitamin D is a well-established inducer of endogenous LL-37 production, which provides one mechanism for vitamin D's immune-protective associations. The primary barrier to therapeutic LL-37 application is its clinical limitations. Despite strong in vitro antimicrobial and immunomodulatory data, LL-37 faces significant hurdles: it is susceptible to rapid proteolytic degradation in biological fluids, shows cytotoxicity toward mammalian cells at concentrations above its antimicrobial threshold, and is expensive to produce in pharmaceutical quantities. No LL-37 formulation has received regulatory approval as of 2026, and human clinical trials remain in early phases. Research interest is high, with multiple groups pursuing modified analogs with improved stability and selectivity. ## Dosage Route: Subcutaneous injection or topical gel (wound healing) ### Schedule | Period | Dose | | --- | --- | | Research SC (conservative) | 100-500 mcg, 3x/week | | Topical wound healing | 5-50 mcg per cm2, 1-2x daily | | Higher research dose | 1 mg SC, daily | ### Reconstitution - Vial size: 5 mg - Water volume: 5 mL bacteriostatic water - Concentration: 1 mg/mL (1,000 mcg/mL) - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 100 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 100 mcg | 0.10 mL | 10 units | | 250 mcg | 0.25 mL | 25 units | | 500 mcg | 0.50 mL | 50 units | ### Tips - LL-37 can lose activity if vortexed aggressively; gently swirl or roll the vial during reconstitution - Use a 29-31 gauge insulin syringe and inject subcutaneously into the abdomen - Avoid injecting at inflamed or infected tissue directly at the injection site - Store reconstituted solution refrigerated and use within 14 days (LL-37 is more prone to degradation than some other peptides once reconstituted) - LL-37 has a narrow therapeutic window; do not exceed research-established dose ranges ## Side Effects ### Common - Injection site pain, redness, or swelling - Mild inflammatory response at injection site (expected given the peptide's immune-activating properties) - Flushing or warmth - Transient fatigue ### Severe / Theoretical Risks - **Cytotoxicity at excessive doses**: LL-37 disrupts mammalian cell membranes at concentrations only modestly above its antimicrobial concentrations; overdosing is a real risk and can cause local tissue damage or systemic cellular toxicity. - **Inflammatory amplification**: In conditions with existing systemic inflammation (sepsis, autoimmune flare), LL-37's pro-inflammatory immunomodulatory effects could worsen the clinical picture rather than improve it. - **Hemolysis**: LL-37 has demonstrated red blood cell membrane disruption (hemolytic activity) in vitro at higher concentrations; this is a meaningful safety concern for injectable use. - **Rapid degradation with unpredictable effective concentration**: Proteolytic enzymes in plasma rapidly degrade LL-37, making circulating bioavailability highly variable and dose-response relationships uncertain in vivo. ### Contraindications - Active systemic infection with septic features (risk of worsening inflammatory cascade) - Autoimmune disease in active flare - Known hypersensitivity to cathelicidin peptides - Pregnancy or breastfeeding - Hemolytic disorders or severe anemia ## FAQ ### What is LL-37 peptide? LL-37 is the only cathelicidin antimicrobial peptide expressed in humans. This 37-amino acid peptide is released by neutrophils and epithelial cells during infection or injury. It disrupts bacterial cell membranes through pore formation, providing broad-spectrum activity against Gram-positive, Gram-negative, and drug-resistant organisms including MRSA. ### How does LL-37 kill bacteria? LL-37 carries a net positive charge that attracts it to negatively charged bacterial membranes. Upon contact, it adopts a helical shape and inserts into the lipid bilayer, forming transmembrane pores that cause bacterial cell lysis. This membrane-disrupting mechanism works against bacteria regardless of antibiotic resistance profiles. ### Does vitamin D increase LL-37 levels? Yes. Vitamin D is a well-established inducer of endogenous LL-37 production, providing one mechanism for vitamin D's known immune-protective associations. Adequate vitamin D status helps maintain natural LL-37 levels in the skin, lungs, gut, and urogenital tract as a first-line defense. ### What are the side effects of LL-37 injections? Common side effects include injection site pain, inflammatory response at the injection site, flushing, and transient fatigue. Serious risks include cytotoxicity at excessive doses, hemolytic activity against red blood cells, and inflammatory amplification in individuals with existing systemic inflammation or autoimmune conditions. ### What is the LL-37 dosage for immune support? Conservative subcutaneous research doses range from 100 to 500 mcg three times per week. Higher research doses reach 1 mg subcutaneously daily. LL-37 has a narrow therapeutic window between antimicrobial and cytotoxic concentrations, making dose precision critically important for safety. ### Is LL-37 FDA approved? No LL-37 formulation has received regulatory approval as of 2026. Despite strong in vitro antimicrobial data, the peptide faces significant therapeutic hurdles including rapid proteolytic degradation, cytotoxicity near antimicrobial concentrations, and high production costs. Human clinical trials remain in early phases. ## References 1. Vandamme D, Landuyt B, Luyten W, et al.. "A comprehensive summary of LL-37, the factotum human cathelicidin peptide." *Cell Immunol*, 2012. PMID: 23246832. https://pubmed.ncbi.nlm.nih.gov/23246832/ 2. Zanetti M. "Cathelicidins, multifunctional peptides of the innate immunity." *J Leukoc Biol*, 2004. PMID: 12960280. https://pubmed.ncbi.nlm.nih.gov/12960280/ 3. Durr UH, Sudheendra US, Ramamoorthy A. "LL-37, the only human member of the cathelicidin family of antimicrobial peptides." *Biochim Biophys Acta*, 2006. PMID: 16716248. https://pubmed.ncbi.nlm.nih.gov/16716248/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. LL-37 has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/ll-37 --- # VIP **Vasoactive Intestinal Peptide (VIP)** Category: Healing > Neuropeptide for Healing and Anti-Inflammation Vasoactive Intestinal Peptide (VIP) is a 28-amino acid neuropeptide found throughout the nervous system and gut that modulates inflammation, immune responses, and circadian rhythms. It actively suppresses pro-inflammatory cytokines while promoting anti-inflammatory mediators, and has gained clinical attention through the Shoemaker CIRS protocol and FDA Fast Track designation for ARDS treatment. ## Key Facts - **Molecular weight:** 3326.8 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/53314964/property/MolecularFormula,MolecularWeight/JSON) - **Molecular formula:** C147H237N43O43S (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/53314964/property/MolecularFormula,MolecularWeight/JSON) - **Sequence length:** 28 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/53314964/synonyms/JSON) - **Primary target:** VPAC1 and VPAC2 receptors (Gs-coupled GPCRs) (source: https://www.guidetopharmacology.org/GRAC/ObjectDisplayForward?objectId=371) - **Mechanism class:** VPAC receptor agonist (VIP/PACAP-family neuropeptide; adenylate cyclase / cAMP-PKA activator) (source: https://www.guidetopharmacology.org/GRAC/ObjectDisplayForward?objectId=371) - **Half-life:** ~1 minute (average IV plasma disappearance half-time in man) (source: https://pubmed.ncbi.nlm.nih.gov/730072/) - **Route of administration:** Intranasal spray (primary in CIRS protocol); IV infusion, subcutaneous, or intracavernosal in clinical/research settings (source: https://www.emjreviews.com/microbiology-infectious-diseases/article/aviptadil-class-effect-of-a-synthetic-vasoactive-intestinal-peptide-as-a-treatment-option-in-patients-with-covid-19-with-severe-respiratory-failure/) - **Regulatory status:** Not FDA approved. Synthetic VIP (aviptadil/ZYESAMI/RLF-100) received FDA Fast Track designation (2020) for COVID-19 ARDS; FDA declined EUA twice (2021, 2022). Investigational (IND) only in US/EU. (source: https://www.globenewswire.com/news-release/2020/06/24/2052448/0/en/NeuroRx-and-Relief-Therapeutics-Announce-Fast-Track-Designation-Granted-by-the-FDA-to-RLF-100-Aviptadil-for-the-Treatment-of-Respiratory-Distress-in-COVID-19.html) - **CAS number:** 40077-57-4 (PubChem CID 53314964; alternate 37221-79-7 also listed in PubChem synonyms) (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/53314964/synonyms/JSON) ## Overview Vasoactive Intestinal Peptide (VIP) is a 28-amino acid neuropeptide and neuromodulator produced throughout the central and peripheral nervous system. It is found in high concentrations in the gut, pancreas, lungs, and hypothalamus (specifically the suprachiasmatic nucleus, the brain's master circadian clock). VIP belongs to the glucagon superfamily of peptides and shares structural similarities with secretin, glucagon, and pituitary adenylate cyclase-activating peptide (PACAP). Despite the 'vasoactive' designation from its early characterization as a vasodilator, VIP's biological roles extend far beyond vascular tone, encompassing inflammation regulation, immune modulation, circadian rhythm synchronization, neuroprotection, and gastrointestinal secretion. VIP exerts its effects primarily through two G-protein-coupled receptor subtypes: VPAC1 (widely distributed across immune cells, lungs, liver, and intestine) and VPAC2 (predominant in smooth muscle, heart, and thymus). Both receptors couple to Gs proteins, activating adenylate cyclase and increasing intracellular cyclic AMP (cAMP) concentrations. Elevated cAMP activates protein kinase A (PKA), which phosphorylates downstream transcription factors including CREB, ultimately regulating gene expression for anti-inflammatory mediators. The result is smooth muscle relaxation, vasodilation, and a coordinated shift in immune cell behavior away from pro-inflammatory phenotypes and toward tolerogenic, anti-inflammatory states. The immunomodulatory profile of VIP is one of its most clinically significant properties. VIP actively suppresses the production of pro-inflammatory cytokines including TNF-alpha, IL-1, IL-6, IL-12, and IFN-gamma from activated macrophages and T cells, while simultaneously upregulating anti-inflammatory mediators including IL-10, IL-1 receptor antagonist, and TGF-beta. VIP also inhibits macrophage activation and promotes the differentiation of regulatory T cells (Tregs) over pro-inflammatory Th1 and Th17 phenotypes. This shift in cytokine balance has made VIP a subject of intense interest in autoimmune and inflammatory conditions including rheumatoid arthritis, Crohn's disease, ulcerative colitis, multiple sclerosis, and septic shock. In the clinical arena, VIP has gained attention through two specific applications. First, Ritchie Shoemaker's Chronic Inflammatory Response Syndrome (CIRS) protocol incorporates VIP nasal spray as a final-stage intervention after other biomarkers have been normalized, targeting persistent neuroinflammatory symptoms in patients exposed to water-damaged building environments. Second, aviptadil (a synthetic VIP formulation) received FDA Fast Track designation for Acute Respiratory Distress Syndrome (ARDS) associated with COVID-19, based on VIP's known protective effects in pulmonary vascular smooth muscle and its anti-cytokine activity. ## Dosage Route: Intranasal spray (primary), subcutaneous injection, or IV infusion (research/clinical) ### Schedule | Period | Dose | | --- | --- | | CIRS protocol (Month 1) | 50 mcg per nostril, 4x daily alternating nostrils | | CIRS protocol (Month 2) | 100 mcg per nostril, 4x daily alternating nostrils | | General anti-inflammatory | 50 mcg intranasal 2-4x daily | | Subcutaneous (research) | 25-100 mcg subcutaneous 1-2x daily | ### Reconstitution - Vial size: 10 mg - Water volume: 2 mL - Concentration: 5 mg/mL - Per unit: Each 0.1 mL = 500 mcg; further dilute 1:10 for accurate low-dose subcutaneous measurement ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 25 mcg | 0.005 mL (requires dilution) | Dilute stock 1:10 first | | 50 mcg | 0.010 mL (requires dilution) | Dilute stock 1:10 first | | 100 mcg | 0.020 mL | From 5 mg/mL stock | ### Tips - In the Shoemaker CIRS protocol, VIP nasal spray is introduced as the final step only after other protocol steps have been completed and relevant inflammatory markers are within acceptable ranges - For intranasal use: prime the atomizer before first use, tilt head slightly forward, and gently sniff while actuating - Alternate nostrils with each administration to prevent mucosal irritation - For subcutaneous injection, consider diluting the stock solution 1:10 with bacteriostatic water for accurate low-dose measurement - Refrigerate at 2-8 degrees Celsius and protect from light -- VIP is susceptible to degradation at room temperature - Use within 4 weeks of reconstitution ### Local vs. Systemic Administration - Local: Intranasal spray targets the nasal and sinus mucosa and provides CNS access via the olfactory pathway - Systemic: Subcutaneous or IV administration delivers systemic anti-inflammatory and immunomodulatory effects ## Side Effects ### Common - Facial flushing or warmth related to VIP's vasodilatory activity - Mild headache, likely secondary to localized vasodilation - Nasal irritation or congestion with repeated intranasal dosing - Transient hypotension, particularly with higher doses or in individuals with pre-existing low blood pressure - Occasional nausea with higher doses or subcutaneous administration ### Severe / Theoretical Risks - **Hypotension**: Significant blood pressure drops are a dose-dependent risk, particularly with parenteral administration. This is the primary dose-limiting adverse effect in clinical trials with injectable formulations. - **Tachycardia**: Reflex tachycardia in response to vasodilation can occur with higher doses. Typically self-limited. - **Allergic reactions**: Rare; hypersensitivity to the peptide or formulation components is possible. - **Immunosuppressive effects**: VIP's potent anti-inflammatory and tolerogenic effects could theoretically impair immune defense in individuals with active severe infections if VIP therapy is not appropriately timed and supervised. ### Contraindications - Hypotension or conditions predisposing to low blood pressure - Concurrent use of antihypertensive medications without careful blood pressure monitoring - Pregnancy and breastfeeding (insufficient safety data for therapeutic use) - Known hypersensitivity to VIP or formulation components - Active severe infection without concurrent antimicrobial treatment ## FAQ ### What is VIP peptide and what does it do? Vasoactive Intestinal Peptide (VIP) is a 28-amino acid neuropeptide found throughout the nervous system and gut. It suppresses pro-inflammatory cytokines including TNF-alpha, IL-1, IL-6, and IL-12 while promoting anti-inflammatory mediators. It also modulates circadian rhythms and has received FDA Fast Track designation for ARDS. ### How is VIP used in the Shoemaker CIRS protocol? In the Shoemaker Chronic Inflammatory Response Syndrome protocol, VIP nasal spray is introduced as the final-stage intervention after other biomarkers have been normalized. It targets persistent neuroinflammatory symptoms in patients exposed to water-damaged building environments, starting at 50 mcg per nostril four times daily. ### What is the VIP nasal spray dosage? The CIRS protocol starts at 50 mcg per nostril four times daily in month one, increasing to 100 mcg per nostril four times daily in month two. For general anti-inflammatory use, 50 mcg intranasally two to four times daily is typical. Subcutaneous research doses are 25 to 100 mcg once or twice daily. ### What are VIP peptide side effects? Common side effects include facial flushing from vasodilation, mild headache, nasal irritation with repeated intranasal dosing, transient hypotension particularly with higher doses, and occasional nausea. The primary dose-limiting effect is significant blood pressure drops, especially with parenteral administration. ### Is VIP safe for people with low blood pressure? VIP is contraindicated for people with hypotension or conditions predisposing to low blood pressure. Its potent vasodilatory activity can cause significant blood pressure drops, particularly with injectable formulations. Concurrent use of antihypertensive medications requires careful blood pressure monitoring. ### What is aviptadil and how does it relate to VIP? Aviptadil is a synthetic VIP formulation that received FDA Fast Track designation for Acute Respiratory Distress Syndrome associated with COVID-19. It leverages VIP's known protective effects on pulmonary vascular smooth muscle and its anti-cytokine activity to address severe respiratory inflammation. ## References 1. Said SI. "The discovery of VIP: initially looked for in the lung, isolated from intestine, and identified as a neuropeptide." *Peptides*, 2007. PMID: 17719695. https://pubmed.ncbi.nlm.nih.gov/17719695/ 2. Delgado M, Pozo D, Ganea D. "The significance of vasoactive intestinal peptide in immunomodulation." *Pharmacol Rev*, 2004. PMID: 15169929. https://pubmed.ncbi.nlm.nih.gov/15169929/ 3. Offen D, Sherki Y, Bodner E, et al.. "Vasoactive intestinal peptide (VIP) prevents neurotoxicity in neuronal cultures: relevance to neuroprotection in Parkinson's disease [^3]." *Brain Res*, 2000. PMID: 10784133. https://pubmed.ncbi.nlm.nih.gov/10784133/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. VIP has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/vip --- # Glutathione **Glutathione (GSH)** Category: Antioxidant > Master Antioxidant for Cellular Protection Glutathione is the most abundant intracellular antioxidant in the human body, a tripeptide composed of glutamate, cysteine, and glycine. It plays a central role in neutralizing reactive oxygen species, detoxifying xenobiotics, and maintaining the reduced state of other antioxidants. Injectable glutathione bypasses the poor oral bioavailability of the compound and is studied for liver disease, oxidative stress, and skin pigmentation modulation. ## Key Facts - **Molecular weight:** 307.33 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/124886/property/MolecularFormula,MolecularWeight,IUPACName/JSON) - **Molecular formula:** C10H17N3O6S (source: https://pubchem.ncbi.nlm.nih.gov/compound/124886) - **Sequence length:** 3 (source: https://pubchem.ncbi.nlm.nih.gov/compound/124886) - **Primary target:** Glutathione peroxidases (GPx), glutathione reductase, and glutathione S-transferases; direct scavenger of reactive oxygen species via the cysteine thiol group (source: https://pubchem.ncbi.nlm.nih.gov/compound/124886) - **Mechanism class:** Endogenous thiol antioxidant and redox cofactor (tripeptide antioxidant) (source: https://pubchem.ncbi.nlm.nih.gov/compound/124886) - **Half-life:** 14.1 +/- 9.2 minutes (human plasma, IV 2 g/m2) (source: https://pubmed.ncbi.nlm.nih.gov/1907548/) - **Route of administration:** Intravenous infusion or subcutaneous injection (oral has very poor bioavailability) (source: https://pubchem.ncbi.nlm.nih.gov/compound/124886) - **Regulatory status:** Not FDA-approved for any indication; injectable/compounded glutathione is not FDA-reviewed for safety or efficacy (FDA flagged endotoxin safety concerns in compounded sterile injectable glutathione, Feb 1, 2019) (source: https://www.fda.gov/drugs/human-drug-compounding/fda-highlights-concerns-using-dietary-ingredient-glutathione-compound-sterile-injectables) - **CAS number:** 70-18-8 (source: https://pubchem.ncbi.nlm.nih.gov/compound/124886) ## Overview Glutathione is a tripeptide composed of three amino acids: glutamate, cysteine, and glycine, joined by an unusual peptide bond between the gamma-carboxyl group of glutamate and the amino group of cysteine. Its chemical designation is gamma-L-glutamyl-L-cysteinylglycine (GSH). Glutathione is the most abundant intracellular antioxidant in the human body, present in virtually every cell, with particularly high concentrations in the liver, which relies on it for detoxification. The body produces glutathione endogenously, but production declines with age, poor nutrition, chronic illness, oxidative stress, and certain medications. This decline is associated with accelerated cellular aging and reduced resilience to metabolic insults. The core antioxidant mechanism of glutathione operates through its sulfur-containing thiol (-SH) group on the cysteine residue. This thiol group donates electrons to neutralize reactive oxygen species (ROS), free radicals, and peroxides. The reaction is catalyzed primarily by glutathione peroxidases (GPxs), which convert harmful peroxides to water while oxidizing GSH to its disulfide form (GSSG). The cell then regenerates GSH from GSSG via glutathione reductase using NADPH as the electron donor, creating a continuous antioxidant recycling cycle. Beyond direct radical scavenging, glutathione participates in the detoxification of xenobiotics through glutathione S-transferase enzymes, conjugating toxic compounds for excretion. It also maintains the reduced state of other antioxidants including vitamins C and E, amplifying their effectiveness. Clinical research on injectable glutathione covers several domains. In Parkinson's disease, small pilot studies have suggested that intravenous glutathione may temporarily improve motor symptoms, though larger controlled trials have not confirmed consistent benefit. In non-alcoholic fatty liver disease (NAFLD), a Japanese open-label, single-arm pilot study (Honda et al., 2017) found that oral L-glutathione at 300 mg/day for 4 months reduced ALT liver enzyme levels and markers of oxidative stress; because the trial had no placebo arm, the improvement reflects a within-subject pre-to-post change rather than a placebo-controlled comparison. Skin-lightening studies have examined glutathione's ability to shift melanin synthesis from darker eumelanin to lighter phaeomelanin; a systematic review published in PMC found evidence of modest efficacy at 500-2,000 mg IV weekly but noted significant study quality limitations. Regarding pharmacokinetics, IV glutathione achieves immediate systemic bioavailability, but plasma half-life is extremely short (on the order of minutes), with rapid uptake by tissues and renal clearance limiting circulating concentrations. It is important to note that oral glutathione has very poor bioavailability due to intestinal degradation. Liposomal oral formulations and precursor supplementation (N-acetylcysteine, alpha-lipoic acid) offer alternative strategies for raising intracellular GSH. Injectable glutathione bypasses this absorption problem but introduces its own risks including anaphylaxis risk with intravenous administration and concerns about non-physiological plasma concentrations causing reductive stress that impairs mitochondrial and immune function if doses are excessive. ## Dosage Route: Intravenous infusion or subcutaneous injection ### Schedule | Period | Dose | | --- | --- | | IV infusion (standard) | 600-1,400 mg, 1-3x/week | | SC injection (research) | 200-600 mg, daily or 3x/week | | Maintenance IV | 500 mg, weekly | | Liver disease (research, oral) | 300 mg/day, daily x 4 months | ### Reconstitution - Vial size: 600 mg - Water volume: 3 mL bacteriostatic water - Concentration: 200 mg/mL - Per unit: Each 1.0 mL = 200 mg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 200 mg | 1.0 mL | SC or IV | | 400 mg | 2.0 mL | SC or IV | | 600 mg | 3.0 mL | SC or IV | ### Tips - For subcutaneous injection, use a 25-27 gauge needle into abdominal subcutaneous fat - IV administration must be performed by a licensed healthcare professional - Store reconstituted solution refrigerated and use within 24 hours for IV; within 7 days for SC - Rotate injection sites to avoid local tissue reactions - Administer IV slowly to reduce flushing and reduce anaphylaxis risk ## Side Effects ### Common - Injection site discomfort, redness, or bruising - Headache following IV infusion - Nausea or cramping - Flushing during IV administration - Fatigue after high-dose sessions ### Severe / Theoretical Risks - **Anaphylaxis**: Rare but documented with IV administration; risk is higher with rapid infusion rates; requires epinephrine availability during IV sessions. - **Reductive stress at high doses**: Supraphysiological glutathione concentrations can paradoxically impair mitochondrial function and immune cell signaling by over-reducing redox-sensitive signaling molecules. - **Hepatotoxicity risk**: Emerging case reports and pharmacology literature flag potential liver enzyme elevations with prolonged high-dose IV use; contradicts its use in liver disease without medical supervision. - **Skin depigmentation**: Prolonged high-dose use may produce uneven or excessive skin lightening, which some users seek but others consider an adverse outcome. ### Contraindications - Known hypersensitivity to glutathione or sulfur compounds - Asthma (IV glutathione has triggered bronchospasm in susceptible patients) - Concurrent chemotherapy (glutathione may interfere with the oxidative mechanism of certain cancer drugs by protecting tumor cells) - Pregnancy or breastfeeding (insufficient safety data) ## FAQ ### What is glutathione and why is it important? Glutathione is the most abundant intracellular antioxidant in the human body, a tripeptide composed of glutamate, cysteine, and glycine. It neutralizes reactive oxygen species, detoxifies harmful compounds through conjugation, and maintains the reduced state of other antioxidants including vitamins C and E. ### Why is injectable glutathione better than oral supplements? Oral glutathione has very poor bioavailability due to intestinal degradation. Injectable glutathione bypasses this absorption problem entirely, achieving immediate systemic bioavailability. Alternative oral strategies include liposomal formulations or precursor supplementation with N-acetylcysteine and alpha-lipoic acid. ### What is the recommended glutathione IV dosage? Standard IV infusion doses range from 600 to 1,400 mg administered one to three times per week. Subcutaneous doses are typically 200 to 600 mg daily or three times weekly. For liver disease research, oral L-glutathione at 300 mg daily for four months has been studied (Honda et al., 2017). IV administration must be performed by licensed healthcare professionals. ### Can glutathione lighten skin? Research shows glutathione can shift melanin synthesis from darker eumelanin to lighter phaeomelanin. A systematic review found modest efficacy at 500 to 2,000 mg IV weekly, but noted significant study quality limitations. Prolonged high-dose use may produce uneven or excessive skin lightening. ### What are glutathione injection side effects? Common side effects include injection site discomfort, headache following IV infusion, nausea, flushing, and fatigue after high-dose sessions. Serious risks include rare anaphylaxis with IV administration, potential hepatotoxicity with prolonged high doses, and reductive stress from supraphysiological concentrations. ### Who should not take glutathione injections? People with known hypersensitivity to sulfur compounds, asthma (risk of bronchospasm with IV glutathione), concurrent chemotherapy (may protect tumor cells from treatment), and pregnant or breastfeeding women should avoid glutathione injections. Always consult a healthcare provider before starting. ## References 1. Richie JP, Nichenametla S, Neiber W, et al.. "Randomized controlled trial of oral glutathione supplementation on body stores of glutathione." *Eur J Nutr*, 2015. PMID: 24791752. https://pubmed.ncbi.nlm.nih.gov/24791752/ 2. Kumar P, Osahon OW, Sekhar RV. "Supplementing Glycine and N-Acetylcysteine (GlyNAC) in Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, and Aging Hallmarks: A Randomized Clinical Trial." *J Gerontol A Biol Sci Med Sci*, 2023. PMID: 35975308. https://pubmed.ncbi.nlm.nih.gov/35975308/ 3. Sekhar RV. "GlyNAC Supplementation Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Aging Hallmarks, Metabolic Defects, Muscle Strength, Cognitive Decline, and Body Composition: Implications for Healthy Aging." *J Nutr*, 2021. PMID: 34587244. https://pubmed.ncbi.nlm.nih.gov/34587244/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Glutathione has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/glutathione --- # IGF-1 LR3 **IGF-1 LR3 (Insulin-Like Growth Factor 1 Long Arg3)** Category: Growth/Strength > Long-Acting Growth Factor for Muscle and Strength IGF-1 LR3 is a synthetic 83-amino acid analog of endogenous IGF-1 with reduced binding to IGF binding proteins, resulting in a half-life of approximately 20-30 hours. It activates the IGF-1 receptor to drive muscle hypertrophy, satellite cell activation, and protein synthesis through PI3K/Akt and MAPK/ERK pathways. It is studied for its anabolic potential in skeletal muscle and has clinical precedent in conditions such as Laron syndrome and HIV-associated wasting. ## Key Facts - **Molecular weight:** ~9,111 Da (9.1 kDa) (source: https://www.prospecbio.com/long_r3_igf1_human) - **Sequence length:** 83 (source: https://www.prospecbio.com/long_r3_igf1_human) - **Primary target:** IGF-1 receptor (IGF-1R), a receptor tyrosine kinase (source: https://www.guidetopharmacology.org/GRAC/ObjectDisplayForward?objectId=1801) - **Mechanism class:** IGF-1 receptor agonist (synthetic long-acting IGF-1 analog with low IGFBP affinity) (source: https://pubmed.ncbi.nlm.nih.gov/17172665/) - **Route of administration:** Subcutaneous injection (most common); intramuscular injection (some protocols) (source: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=a8b27a1b-a611-4f91-ad22-76d4b390c3ae) - **Regulatory status:** Not FDA-approved for human use (research-use-only); prohibited at all times under the WADA Prohibited List (peptide hormones/growth factors class). Distinct from FDA-approved mecasermin/Increlex, a different IGF-1 product. (source: https://www.usada.org/spirit-of-sport/igf-1-and-the-world-anti-doping-agency-prohibited-list/) ## Overview IGF-1 LR3 (Insulin-Like Growth Factor 1 Long Arg3) is a synthetic, modified analog of endogenous IGF-1 consisting of 83 amino acids, compared to the native 70-amino acid structure. Two key structural modifications distinguish it: an arginine substitution at position 3 (replacing glutamic acid) and an additional 13-amino acid N-terminal extension. These changes dramatically reduce IGF-1 LR3's binding affinity for IGF binding proteins (IGFBPs), which normally sequester native IGF-1 in the bloodstream and limit its bioavailability. The result is an analog with a half-life measured in hours (approximately 20-30 hours) rather than the minutes characteristic of native IGF-1, and correspondingly greater systemic exposure and bioactivity per dose. The primary mechanism of IGF-1 LR3 involves binding to the IGF-1 receptor (IGF-1R), a receptor tyrosine kinase expressed on the surface of muscle cells, bone cells, adipocytes, and many other tissues. Receptor activation triggers two major downstream signaling cascades: the PI3K/Akt pathway, which drives protein synthesis, glucose uptake, and cell survival; and the MAPK/ERK pathway, which stimulates cellular proliferation and differentiation. In skeletal muscle specifically, IGF-1 LR3 activates satellite cells (muscle stem cells), promotes their differentiation into mature myofibers, and drives both hypertrophy (increased cell size) and hyperplasia (increased cell number). The latter effect, genuine muscle fiber hyperplasia, is less commonly achievable through resistance training alone and represents a distinct anabolic mechanism. Research on IGF-1 and its analogs in skeletal muscle has been extensive in preclinical settings. A comprehensive review published in PMC (Optimizing IGF-I for skeletal muscle therapeutics) documented that IGF-1 overexpression in animal models prevented age-related muscle atrophy, enhanced recovery from injury, and increased muscle mass well beyond normal genetic limits. Clinically, IGF-1 therapies are approved by the FDA under the brand name Increlex for severe primary IGF-1 deficiency (Laron syndrome) and short stature associated with growth hormone receptor mutations. These indications are distinct from research use of IGF-1 LR3, which is not FDA-approved. In HIV-associated muscle wasting, clinical studies with IGF-1 and related analogs have shown meaningful preservation of lean mass, supporting the mechanistic case for anabolic utility in catabolic states. The performance-enhancement research context for IGF-1 LR3 is extensive in the bodybuilding and athletic community but poorly represented in peer-reviewed literature. Extrapolations are drawn primarily from native IGF-1 studies. The extended half-life of the LR3 variant means that systemic exposure is substantially greater than native IGF-1, which raises both the potential for anabolic benefit and the risk of off-target effects, including insulin-like metabolic disruption. This is not a compound for casual use; its potency relative to native IGF-1 demands careful dosing and professional oversight. ## Dosage Route: Subcutaneous injection (most common); intramuscular injection (some protocols) ### Schedule | Period | Dose | | --- | --- | | Conservative start | 20-40 mcg every other day, 4 weeks | | Intermediate | 50-80 mcg daily or EOD, 4-6 weeks | | Research upper range | 100-120 mcg daily, 4-6 weeks max | ### Reconstitution - Vial size: 1 mg (1,000 mcg) - Water volume: 2 mL bacteriostatic water - Concentration: 500 mcg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 50 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 50 mcg | 0.10 mL | 10 units | | 80 mcg | 0.16 mL | 16 units | | 100 mcg | 0.20 mL | 20 units | ### Tips - Inject post-workout or with a carbohydrate-containing meal to reduce hypoglycemia risk - Use a 29-31 gauge insulin syringe for subcutaneous administration - Store reconstituted solution refrigerated and use within 28 days - Acetic acid (0.6%) is sometimes used instead of bacteriostatic water to improve solubility; check vendor specifications - Cycle off for an equal period after each cycle to prevent receptor desensitization ### Cycling - On period: 4-6 weeks - Off period: 4-6 weeks - Notes: Daily use without cycling leads to downregulation of IGF-1R, reducing anabolic response while maintaining side effect exposure. ## Side Effects ### Common - Hypoglycemia (low blood sugar), especially if injecting without eating; symptoms include shakiness, sweating, confusion - Water retention and mild edema in extremities - Joint pain or stiffness at higher doses - Injection site pain, redness, or swelling - Fatigue or lethargy following injection ### Severe / Theoretical Risks - **Insulin resistance**: Chronic IGF-1 LR3 use can impair normal insulin signaling, increasing long-term diabetes risk; the extended half-life amplifies this effect compared to native IGF-1. - **Acromegaly-like features**: Prolonged exposure to elevated IGF-1 signaling can cause jaw enlargement, hand and foot growth, and organ enlargement (particularly cardiomegaly and hepatomegaly) analogous to acromegaly. - **Cancer promotion**: IGF-1R signaling is a well-established growth pathway for multiple cancers; epidemiological data links chronically elevated IGF-1 to increased risk of colorectal, breast, and prostate cancer; use in individuals with cancer history is contraindicated. - **Receptor desensitization**: Daily use without cycling leads to downregulation of IGF-1R, reducing anabolic response while maintaining side effect exposure. ### Contraindications - Active malignancy or cancer history (any IGF-1 pathway-dependent cancer risk is significantly elevated) - Diabetes or insulin resistance - Active growth plates (use in adolescents is contraindicated) - Pregnancy or breastfeeding - Acromegaly or gigantism - Concurrent use of insulin or other anabolic hormones without medical supervision ## FAQ ### What is IGF-1 LR3 and how does it differ from regular IGF-1? IGF-1 LR3 is a modified 83-amino acid analog of natural IGF-1 with two key changes: an arginine substitution at position 3 and a 13-amino acid N-terminal extension. These modifications reduce binding to IGF binding proteins, extending the half-life from minutes to approximately 20 to 30 hours. ### How does IGF-1 LR3 build muscle? IGF-1 LR3 activates the IGF-1 receptor, triggering two major pathways: PI3K/Akt (driving protein synthesis) and MAPK/ERK (stimulating cell proliferation). In skeletal muscle, it activates satellite cells, promotes their differentiation into mature fibers, and drives both hypertrophy and genuine muscle fiber hyperplasia. ### What is the standard IGF-1 LR3 dosage? Conservative protocols start at 20 to 40 mcg every other day for four weeks. Intermediate doses are 50 to 80 mcg daily or every other day for four to six weeks. The upper research range is 100 to 120 mcg daily for a maximum of six weeks, followed by an equal off-cycle period. ### What are the dangers of IGF-1 LR3? Major risks include hypoglycemia, insulin resistance with chronic use, and promotion of cancer cell growth through IGF-1R signaling. Prolonged exposure can cause acromegaly-like features including jaw enlargement and organ growth. It is contraindicated for anyone with cancer history or active diabetes. ### Does IGF-1 LR3 cause cancer? IGF-1R signaling is a well-established growth pathway for multiple cancers. Epidemiological data links chronically elevated IGF-1 to increased risk of colorectal, breast, and prostate cancer. Use in individuals with any cancer history is strongly contraindicated due to this established biological mechanism. ### Why do you need to cycle IGF-1 LR3? Daily use without cycling causes downregulation of the IGF-1 receptor, reducing anabolic response while maintaining side effect exposure. Standard cycling is four to six weeks on followed by four to six weeks off. This preserves receptor sensitivity and maintains the peptide's effectiveness. ## References 1. Conlon MA, Tomas FM, Owens PC, et al.. "Long R3 insulin-like growth factor-I (IGF-I) infusion stimulates organ growth but reduces plasma IGF-I, IGF-II and IGF binding protein concentrations in the guinea pig." *J Endocrinol*, 1995. PMID: 7561636. https://pubmed.ncbi.nlm.nih.gov/7561636/ 2. Dunaiski V, Belford DA. "Long [R3] insulin-like growth factor-I reduces growth, plasma growth hormone, IGF binding protein-3 and endogenous IGF-I concentrations in pigs." *J Endocrinol*, 1997. PMID: 9488001. https://pubmed.ncbi.nlm.nih.gov/9488001/ 3. Voorhamme D, Bhatt RR. "LONG R3IGF-I as a more potent alternative to insulin in serum-free culture of HEK293 cells." *Mol Biotechnol*, 2006. PMID: 17172665. https://pubmed.ncbi.nlm.nih.gov/17172665/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. IGF-1 LR3 has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/igf-1-lr3 --- # Sermorelin **Sermorelin (GHRH 1-29)** Category: Growth > Peptide for Growth Hormone Stimulation Sermorelin is a synthetic 29-amino acid peptide representing the biologically active N-terminal fragment of growth hormone-releasing hormone (GHRH). It stimulates the anterior pituitary to produce and secrete growth hormone in a pulsatile, physiologically regulated manner, preserving the natural feedback mechanisms that direct GH replacement bypasses. ## Key Facts - **Molecular weight:** 3357.9 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/16132413/property/MolecularFormula,MolecularWeight/JSON) - **Molecular formula:** C149H246N44O42S (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/16132413/property/MolecularFormula,MolecularWeight/JSON) - **Sequence length:** 29 (source: https://www.guidetopharmacology.org/GRAC/LigandDisplayForward?ligandId=6998) - **Primary target:** Growth hormone-releasing hormone receptor (GHRHR) (source: https://www.guidetopharmacology.org/GRAC/LigandDisplayForward?tab=biology&ligandId=6998) - **Mechanism class:** Growth hormone-releasing hormone (GHRH) receptor agonist / growth hormone secretagogue (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC7108996/) - **Half-life:** 11-12 minutes (after IV or SC administration) (source: https://www.rxlist.com/sermorelin-acetate-drug.htm) - **Route of administration:** Subcutaneous injection (also administered intravenously in diagnostic use) (source: https://www.rxlist.com/sermorelin-acetate-drug.htm) - **Regulatory status:** FDA-approved 1997 (Geref/sermorelin acetate) for pediatric growth hormone deficiency and as a diagnostic of pituitary GH reserve; commercially discontinued 2008 (not for safety/efficacy reasons); no current DailyMed label; now available only as a compounded/503B product, not FDA-approved as a finished drug (source: https://www.federalregister.gov/documents/2013/03/04/2013-04827/determination-that-geref-sermorelin-acetate-injection-05-milligrams-basevial-and-10-milligrams) - **CAS number:** 86168-78-7 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16132413) ## Overview Sermorelin is a synthetic 29-amino acid peptide representing the biologically active N-terminal fragment of growth hormone-releasing hormone (GHRH), the naturally occurring hypothalamic peptide that stimulates the anterior pituitary to produce and secrete human growth hormone (hGH). The full-length GHRH contains 44 amino acids, but research demonstrated that the first 29 are sufficient for full biological activity at the GHRH receptor, making sermorelin a compact and functionally complete analogue. Sermorelin was FDA-approved in 1997 (brand name Geref) for the treatment of growth hormone deficiency in children with idiopathic growth failure, and it was also approved for use as a diagnostic test of pituitary GH reserve. The mechanism of action of sermorelin is categorically different from direct growth hormone replacement therapy. Exogenous recombinant human GH (rhGH) bypasses the pituitary entirely, delivering preformed GH directly into the circulation. This approach suppresses the hypothalamic-pituitary axis, creates supraphysiological GH peaks, and requires continuous administration to maintain effects. Sermorelin, by contrast, binds to the GHRH receptor on pituitary somatotroph cells, stimulating these cells to synthesize and release the body's own endogenous GH in a pulsatile, physiologically regulated manner. Because sermorelin's effects are subject to normal negative feedback via somatostatin (the hypothalamic GH-inhibitory hormone), it is pharmacologically very difficult to overdose. The pituitary remains in control of ultimate GH output, preserving the natural pulsatile secretion pattern that recombinant GH cannot replicate. Published clinical evidence for sermorelin is substantial relative to many research peptides. A 1996 study demonstrated that daily sermorelin injection increased height velocity in 74 percent of GH-deficient children within 6 months. Significant increases in height velocity were maintained through 12 months and in a subset of children through 36 months of continued treatment. The 1999 publication by Alba et al. confirmed that sermorelin successfully stimulated growth in the majority of GH-deficient children treated. Importantly, sermorelin also stimulates the production of insulin-like growth factor 1 (IGF-1) from the liver, and IGF-1 is thought to mediate many of GH's anabolic and metabolic effects, including lean mass accretion, fat metabolism, bone density, and tissue repair. The FDA discontinued the commercial product in 2008 for economic reasons (not safety), and sermorelin currently exists as a compounded pharmaceutical available through licensed compounding pharmacies with a valid prescription. Off-label use of sermorelin in adults has expanded significantly in the context of age-related growth hormone decline. GH secretion decreases by roughly 14 percent per decade after peak secretion in young adulthood. Adult users of sermorelin report gradual improvements in body composition, sleep quality (GH is predominantly secreted during slow-wave sleep), energy, skin texture, and recovery from exercise over courses of 3-6 months. Results are generally slower and more modest than with direct GH replacement but without the associated risks of receptor downregulation or supraphysiological exposure. ## Dosage Route: Subcutaneous injection, once daily at bedtime ### Schedule | Period | Dose | | --- | --- | | Standard adult (anti-aging) | 200-300 mcg before bedtime | | Higher adult dose | 300-500 mcg before bedtime | | Pediatric (approved use) | 30 mcg/kg before bedtime | | Cycle duration | 3-6 months continuously | ### Reconstitution - Vial size: 5 mg - Water volume: 2.5 mL - Concentration: 2 mg/mL (2,000 mcg/mL) - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 200 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 200 mcg | 0.10 mL | 10 units | | 300 mcg | 0.15 mL | 15 units | | 500 mcg | 0.25 mL | 25 units | ### Tips - Bedtime administration is strongly preferred -- it aligns with the body's natural GH secretion peak during slow-wave sleep - Inject subcutaneously into the lower abdomen or outer thigh, rotating sites with each injection - Use a 27-31 gauge, 5/16 to 1/2 inch needle - Pinch the skin to lift subcutaneous tissue before injecting - Store reconstituted vials refrigerated at 2-8 degrees Celsius and use within 30 days - Allow the vial to reach room temperature before injection to reduce discomfort ### Cycling - On period: 3-6 months - Off period: 1-2 months - Notes: Cycling helps maintain pituitary sensitivity and prevents receptor desensitization ## Side Effects ### Common - Injection site reactions (redness, swelling, pain, itching) - Flushing of the face or upper body shortly after injection - Mild headache, typically resolving within 1-2 hours - Nausea or vomiting (less common; more likely at higher doses) - Dizziness or lightheadedness, particularly when standing quickly after injection - Water retention and mild fluid retention in initial weeks ### Severe / Theoretical Risks - **Hypothyroidism**: GH stimulation can unmask or worsen pre-existing subclinical hypothyroidism. Thyroid function should be monitored during extended sermorelin courses. - **Glucose metabolism changes**: GH has antagonistic effects on insulin. Individuals with pre-diabetes, diabetes, or metabolic syndrome should monitor blood glucose carefully and discuss sermorelin use with their physician before initiating therapy. - **Carpal tunnel syndrome**: Fluid retention from elevated GH/IGF-1 can cause carpal tunnel symptoms, particularly with higher doses or in predisposed individuals. - **IGF-1 elevation and cancer risk**: Elevated IGF-1 has been associated with increased risk of certain cancers in epidemiological studies, though causality has not been established. This is relevant for long-term, high-dose use. ### Contraindications - Active malignancy (GH and IGF-1 can promote cellular proliferation) - Pregnancy (insufficient safety data) - Hypothyroidism (untreated; GH therapy may worsen) - Diabetes mellitus or pre-diabetes (without careful monitoring) - Known hypersensitivity to sermorelin or GHRH - Children with closed epiphyses (growth plates) ## FAQ ### What is Sermorelin and how does it work? Sermorelin is a synthetic 29-amino acid peptide representing the biologically active fragment of growth hormone-releasing hormone (GHRH). It stimulates the pituitary to produce and secrete growth hormone in a pulsatile, physiologically regulated manner, preserving natural feedback mechanisms that direct GH replacement bypasses. ### How does Sermorelin differ from HGH injections? Sermorelin stimulates your pituitary to make its own GH, while HGH injects preformed growth hormone directly into circulation. Sermorelin preserves natural pulsatile secretion patterns and is subject to somatostatin feedback, making overdose pharmacologically very difficult. Results are slower but carry fewer risks. ### What is the recommended Sermorelin dosage? Standard adult anti-aging doses are 200 to 300 mcg injected subcutaneously before bedtime. Higher doses reach 300 to 500 mcg nightly. Bedtime administration aligns with the body's natural GH secretion peak during slow-wave sleep. Typical cycles run 3 to 6 months with 1 to 2 months off. ### How long does Sermorelin take to show results? Sermorelin produces gradual improvements over 3 to 6 months. Users typically report improved sleep quality within the first few weeks, followed by gradual changes in body composition, energy, skin texture, and exercise recovery. Results are generally slower and more modest than direct GH replacement. ### What are Sermorelin side effects? Common side effects include injection site reactions, facial flushing, mild headache, occasional nausea, dizziness, and water retention in initial weeks. Serious risks include unmasking subclinical hypothyroidism, glucose metabolism changes in pre-diabetic individuals, and carpal tunnel syndrome from elevated IGF-1. ### Was Sermorelin ever FDA approved? Yes. Sermorelin was FDA-approved in 1997 under the brand name Geref for growth hormone deficiency in children and as a diagnostic test of pituitary GH reserve. The commercial product was discontinued in 2008 for economic reasons, not safety concerns. It currently exists as a compounded pharmaceutical. ## References 1. Prakash A, Goa KL. "Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency." *BioDrugs*, 1999. PMID: 18031173. https://pubmed.ncbi.nlm.nih.gov/18031173/ 2. Walker RF. "Sermorelin: a better approach to management of adult-onset growth hormone insufficiency?." *Clin Interv Aging*, 2006. PMID: 18046908. https://pubmed.ncbi.nlm.nih.gov/18046908/ 3. Khorram O, Laughlin GA, Yen SS. "Endocrine and metabolic effects of long-term administration of [Nle27]growth hormone-releasing hormone-(1-29)-NH2 in age-advanced men and women." *J Clin Endocrinol Metab*, 1997. PMID: 9141536. https://pubmed.ncbi.nlm.nih.gov/9141536/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Sermorelin is not currently FDA-approved (the original approval was discontinued in 2008 for commercial reasons). Off-label use in adults has not been reviewed or approved by the FDA for any indication. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/sermorelin --- # GHRP-2 **GHRP-2 (Pralmorelin)** Category: Growth > Potent Ghrelin Receptor Agonist for Growth Hormone Stimulation GHRP-2 (pralmorelin) is a synthetic hexapeptide that produces some of the highest GH pulse amplitudes per unit dose of any compound in its class. It acts at the ghrelin receptor (GHS-R1a) through a mechanism distinct from GHRH, creating synergistic GH amplification when combined with GHRH analogs. GH levels peak approximately 60 minutes post-injection and normalize within three hours. ## Key Facts - **Molecular weight:** 818.0 (source: https://pubchem.ncbi.nlm.nih.gov/compound/6918245) - **Molecular formula:** C45H55N9O6 (source: https://pubchem.ncbi.nlm.nih.gov/compound/6918245) - **Sequence length:** 6 amino acids (source: https://pubchem.ncbi.nlm.nih.gov/compound/6918245) - **Primary target:** Growth hormone secretagogue receptor 1a (GHS-R1a / ghrelin receptor) (source: https://drugs.ncats.io/drug/pralmorelin) - **Mechanism class:** Growth hormone secretagogue (ghrelin/GHS-R1a receptor agonist) (source: https://www.guidetopharmacology.org/GRAC/LigandDisplayForward?ligandId=1092) - **Route of administration:** Intravenous (clinical/diagnostic use in Japan); subcutaneous injection in research/off-label use per our data (source: https://pubmed.ncbi.nlm.nih.gov/20552695/) - **Regulatory status:** Not FDA-approved for human therapeutic use. Approved in Japan (PMDA, 2004) as a single-dose diagnostic agent (GHRP Kaken 100) for assessing growth hormone deficiency; research-use-only elsewhere (source: https://www.guidetopharmacology.org/GRAC/LigandDisplayForward?ligandId=1092) - **CAS number:** 158861-67-7 (source: https://pubchem.ncbi.nlm.nih.gov/compound/6918245) ## Overview GHRP-2 (Growth Hormone Releasing Peptide-2), also known by its pharmaceutical name pralmorelin, is a synthetic hexapeptide that acts as a potent agonist at the ghrelin receptor (GHS-R1a), triggering robust secretion of growth hormone (GH) from the anterior pituitary. Among the growth hormone secretagogue peptides, GHRP-2 is notable for producing some of the highest GH pulse amplitudes per unit dose of any compound in its class, while being somewhat more favorable than GHRP-6 in terms of appetite stimulation, though this effect is still present. GHRP-2 operates through a receptor and signaling pathway that is distinct from that of growth hormone-releasing hormone (GHRH). Both GHRH and GHRP-2 stimulate GH release, but through different receptor systems that converge at the pituitary level. This complementary mechanism creates a synergistic interaction: when GHRP-2 is co-administered with a GHRH analog such as CJC-1295, the resulting GH pulse is significantly larger than either compound produces alone. Clinical research published in The Journal of Clinical Endocrinology and Metabolism confirmed that GHRP-2 administration acutely increases plasma GH levels, with peak GH concentrations occurring approximately 60 minutes post-injection and returning to baseline within three hours. Research in humans and animal models has examined GHRP-2 in the context of growth hormone deficiency, short stature in children, and body composition modification. A pediatric study used intranasal GHRP-2 at 5 to 15 micrograms per kilogram, administered two to three times daily over three months, and found measurable improvements in growth velocity. GHRP-2 also increases food intake acutely through the same ghrelin pathway, though this effect is less pronounced than with GHRP-6. GHRP-2 has not been approved by the FDA for human therapeutic use. It is available as a research compound and is studied in controlled settings. Clinical data supporting its use in healthy adult populations for body composition or anti-aging purposes remains limited. ## Dosage Route: Subcutaneous injection, in a fasted state or at minimum two hours after eating ### Schedule | Period | Dose | | --- | --- | | Entry level | 100 mcg, 2x daily (morning fasted + bedtime) | | Standard research | 100-200 mcg, 2-3x daily | | High dose | 300 mcg, 2-3x daily (diminishing returns above 300 mcg) | | Pediatric (intranasal, study) | 5-15 mcg/kg, 2-3x daily (clinical research protocol only) | | Combined with GHRH analog | 100 mcg GHRP-2 + 100 mcg CJC-1295, 2x daily | ### Reconstitution - Vial size: 5 mg - Water volume: 2.5 mL bacteriostatic water - Concentration: 2 mg/mL (2,000 mcg/mL) - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 200 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 100 mcg | 0.05 mL | 5 units | | 200 mcg | 0.10 mL | 10 units | | 300 mcg | 0.15 mL | 15 units | ### Tips - Inject in a fasted state -- elevated blood glucose or insulin significantly reduces GH release - GH levels typically peak at 60 minutes post-injection and normalize within three hours - The feedback mechanisms governing endogenous GH secretion remain partially intact with GHRP-2, providing some protection against runaway GH elevation - Store reconstituted solution refrigerated and use within 30 days - Keep unreconstituted lyophilized powder frozen until ready to use - Combine with a GHRH analog for synergistic GH amplification if desired ### Cycling - On period: 8-12 weeks - Off period: 4-8 weeks - Notes: Off periods help preserve GHS-R1a receptor sensitivity and maintain GH pulse amplitude ## Side Effects ### Common - Appetite stimulation (less pronounced than GHRP-6; increased hunger within 30-60 minutes of injection) - Elevated cortisol and prolactin (greater degree than ipamorelin; sustained prolactin elevation may cause sexual dysfunction or gynecomastia) - Fluid retention and joint discomfort associated with elevated GH and IGF-1 - Tingling or numbness in the extremities (paresthesia), particularly in the hands - Fatigue or sedation following injection - Mild hypoglycemia in some individuals shortly after injection, before GH-mediated insulin antagonism takes effect ### Severe / Theoretical Risks - **Promotion of tumor growth**: Elevated GH and IGF-1 are potent mitogenic signals. Individuals with active or prior malignancy should not use GH secretagogues. - **Pituitary desensitization**: Continuous high-frequency use can desensitize the GHS-R1a receptor, diminishing GH response over time. - **Carpal tunnel syndrome**: Prolonged elevated IGF-1 can cause progressive carpal tunnel syndrome requiring intervention. ### Contraindications - Active or history of malignancy - Diabetic individuals or those with clinically impaired glucose tolerance - Pregnancy and lactation - Active acromegaly - Pediatric use without physician oversight (open growth plates) - Known hypersensitivity to the compound or formulation components ## FAQ ### What is GHRP-2 and how does it work? GHRP-2 (pralmorelin) is a synthetic hexapeptide that activates the ghrelin receptor (GHS-R1a) to stimulate growth hormone secretion from the anterior pituitary. It produces some of the highest GH pulse amplitudes per unit dose of any compound in its class, with peak levels at approximately 60 minutes post-injection. ### How does GHRP-2 compare to GHRP-6? GHRP-2 produces higher GH pulse amplitudes than GHRP-6 at equivalent doses while causing somewhat less appetite stimulation. However, GHRP-2 elevates cortisol and prolactin more than GHRP-6 or ipamorelin. Both work through the ghrelin receptor and are synergistic when combined with GHRH analogs. ### What is the best GHRP-2 dosage? Entry level doses are 100 mcg twice daily (morning fasted and bedtime). Standard research doses are 100 to 200 mcg two to three times daily. Diminishing returns occur above 300 mcg per dose. Combining 100 mcg GHRP-2 with 100 mcg CJC-1295 twice daily produces synergistic GH amplification. ### Why must GHRP-2 be injected on an empty stomach? Elevated blood glucose and circulating insulin significantly reduce GH release from ghrelin receptor activation. Injecting in a fasted state or at minimum two hours after eating ensures maximum GH pulse amplitude. Eating immediately after the GH pulse peaks at 60 minutes is generally acceptable. ### What are GHRP-2 side effects? Common side effects include appetite stimulation within 30 to 60 minutes, elevated cortisol and prolactin (which may cause sexual dysfunction or gynecomastia), fluid retention, tingling in extremities, fatigue, and mild hypoglycemia. Cycling 8 to 12 weeks on with 4 to 8 weeks off preserves receptor sensitivity. ### Is GHRP-2 FDA approved? GHRP-2 has not been approved by the FDA for any human therapeutic use. A pediatric study used intranasal GHRP-2 to improve growth velocity, but the compound remains classified as a research compound. Clinical data supporting its use in healthy adults for body composition or anti-aging remains limited. ## References 1. [No authors listed]. "Pralmorelin: GHRP 2, GPA 748, growth hormone-releasing peptide 2, KP-102 D, KP-102 LN, KP-102D, KP-102LN." *Drugs R D*, 2004. PMID: 15230633. https://pubmed.ncbi.nlm.nih.gov/15230633/ 2. Laferrere B, Abraham C, Russell CD, et al.. "Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men." *J Clin Endocrinol Metab*, 2005. PMID: 15699539. https://pubmed.ncbi.nlm.nih.gov/15699539/ 3. Bowers CY, Granda R, Mohan S, et al.. "Growth hormone/insulin-like growth factor-1 response to acute and chronic growth hormone-releasing peptide-2, growth hormone-releasing hormone 1-44NH2 and in combination in older men and women with decreased growth hormone secretion." *Endocrine*, 2001. PMID: 11322505. https://pubmed.ncbi.nlm.nih.gov/11322505/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. GHRP-2 has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/ghrp-2 --- # GHRP-6 **GHRP-6 (Growth Hormone Releasing Peptide-6)** Category: Growth > Ghrelin Receptor Agonist for Growth Hormone Stimulation GHRP-6 is a synthetic hexapeptide that stimulates growth hormone secretion by activating the ghrelin receptor (GHS-R1a), producing robust pulsatile GH release through a mechanism independent of the GHRH axis. Its most notable characteristic is intense appetite stimulation occurring within 20-30 minutes of injection, a direct consequence of ghrelin receptor activation in the hypothalamus. ## Key Facts - **Molecular weight:** 873.0 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/4345065/property/MolecularFormula,MolecularWeight,IUPACName/JSON) - **Molecular formula:** C46H56N12O6 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/4345065/property/MolecularFormula,MolecularWeight,IUPACName/JSON) - **Sequence length:** 6 (source: https://pubchem.ncbi.nlm.nih.gov/compound/4345065) - **Primary target:** Growth hormone secretagogue receptor type 1a (GHS-R1a / ghrelin receptor) (source: https://pubmed.ncbi.nlm.nih.gov/23099431/) - **Mechanism class:** Growth hormone secretagogue (ghrelin receptor agonist) (source: https://www.guidetopharmacology.org/GRAC/LigandDisplayForward?tab=biology&ligandId=1093) - **Half-life:** Distribution t1/2 7.6 +/- 1.9 min; elimination t1/2 2.5 +/- 1.1 h (single IV bolus, healthy male volunteers) (source: https://pubmed.ncbi.nlm.nih.gov/23099431/) - **Route of administration:** Subcutaneous injection (research/clinical use); pharmacokinetic study administered as intravenous bolus (source: https://pubmed.ncbi.nlm.nih.gov/23099431/) - **Regulatory status:** Not FDA-approved for any indication; research-use-only, not for human therapeutic use; prohibited by the World Anti-Doping Agency (WADA) (source: https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf) - **CAS number:** 87616-84-0 (source: https://www.chemicalbook.com/ChemicalProductProperty_EN_CB8421540.htm) ## Overview GHRP-6 (Growth Hormone Releasing Peptide-6) is a synthetic hexapeptide that was among the first compounds developed to pharmacologically stimulate growth hormone (GH) secretion through a mechanism independent of the hypothalamic growth hormone-releasing hormone (GHRH) axis. Originally developed as a research tool for studying GH regulation, GHRP-6 has attracted sustained interest in the fields of anti-aging medicine, body composition research, and recovery protocols due to its ability to produce robust, pulsatile GH release. The compound works by binding to and activating the ghrelin receptor, formally known as the growth hormone secretagogue receptor (GHS-R1a). Ghrelin is an endogenous gut hormone involved in appetite regulation, energy balance, and GH pulsatility. GHRP-6 mimics ghrelin's action at this receptor, triggering signaling cascades that include phosphatidylinositol turnover, PKC activation, and intracellular calcium mobilization. Critically, this signaling pathway is entirely separate from the one that GHRH uses, which is why combining GHRP-6 with a GHRH analog (such as CJC-1295) produces synergistic effects on GH output rather than simple additive effects. Beyond growth hormone stimulation, research published in peer-reviewed journals has documented cytoprotective and anti-inflammatory properties for GHRP-6 that appear to be at least partially independent of GH release. These effects have been studied in cardiac, hepatic, and wound-healing models. A clinical safety study in healthy volunteers confirmed that GHRP-6 is well-tolerated, with the most notable acute effect being intense appetite stimulation occurring within 20 to 30 minutes of injection. GHRP-6 is not approved by the FDA for any clinical use. It is classified as a research compound and is not intended for human therapeutic use outside of controlled research settings. ## Dosage Route: Subcutaneous injection, in a fasted state (30-60 minutes before eating or 2+ hours after a meal) ### Schedule | Period | Dose | | --- | --- | | Entry level | 100 mcg, 1-2x daily (minimal appetite stimulation) | | Standard research | 100-200 mcg, 2-3x daily | | High dose | 300 mcg, 2-3x daily (significant hunger) | | Combined with GHRH analog | 100 mcg GHRP-6 + 100 mcg CJC-1295, 2-3x daily | ### Reconstitution - Vial size: 5 mg - Water volume: 2.5 mL bacteriostatic water - Concentration: 2 mg/mL (2,000 mcg/mL) - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 200 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 100 mcg | 0.05 mL | 5 units | | 200 mcg | 0.10 mL | 10 units | | 300 mcg | 0.15 mL | 15 units | ### Tips - Inject in a fasted state -- GH release is blunted by elevated blood glucose and circulating fatty acids - Optimal injection timing windows: upon waking (fasted), pre-workout, and at bedtime - Inject subcutaneously into the abdominal region, thigh, or deltoid area - Expect intense hunger within 20-30 minutes of injection -- have a plan for managing appetite - Research protocols typically run 8-12 weeks followed by a comparable off period to minimize receptor desensitization - Store reconstituted solution refrigerated and use within 30 days ### Cycling - On period: 8-12 weeks - Off period: 8-12 weeks - Notes: Cycling prevents GHS-R1a receptor desensitization and maintains GH pulse responsiveness ## Side Effects ### Common - Intense appetite stimulation within 20-30 minutes of injection (most consistent side effect; mediated by ghrelin receptor activation in the hypothalamus) - Fluid retention and mild puffiness in the hands, feet, and face - Tingling or numbness in the extremities (paresthesia) related to elevated GH and IGF-1 - Fatigue or somnolence after injection, particularly with evening doses - Elevated cortisol and prolactin (more than some other GH secretagogues such as ipamorelin) ### Severe / Theoretical Risks - **Pituitary desensitization**: Chronic high-frequency dosing can desensitize the GHS-R1a receptor, diminishing GH response over time. Cycling protocols are recommended to preserve receptor sensitivity. - **Insulin resistance exacerbation**: GH-mediated antagonism of insulin signaling can worsen pre-existing insulin resistance. Individuals with metabolic syndrome or diabetes should use extreme caution. - **Promotion of malignancy**: Elevated GH and IGF-1 are mitogenic. Use in individuals with active cancer or a history of malignancy is a serious concern requiring specialist evaluation. - **Edema progression**: Water retention can progress to clinically significant edema in susceptible individuals, particularly at higher doses. ### Contraindications - Active or history of malignancy (GH and IGF-1 are growth-promoting) - Diabetic individuals or those with insulin resistance (GH is diabetogenic) - Pregnancy and breastfeeding - Active acromegaly or pre-existing elevated GH/IGF-1 - Pediatric use (open growth plates; GH stimulation may cause disproportionate growth) - Individuals with hypersensitivity to any component of the formulation ## FAQ ### What is GHRP-6 and what does it do? GHRP-6 is a synthetic hexapeptide that stimulates growth hormone secretion by activating the ghrelin receptor (GHS-R1a), producing robust pulsatile GH release through a mechanism independent of the GHRH axis. Its most notable characteristic is intense appetite stimulation occurring within 20 to 30 minutes of injection. ### Does GHRP-6 make you hungry? Yes. Intense appetite stimulation is the most consistent side effect of GHRP-6, occurring within 20 to 30 minutes of injection through ghrelin receptor activation in the hypothalamus. This effect is more pronounced than with GHRP-2 or ipamorelin and can be significant at higher doses. ### What is the GHRP-6 dosage for muscle growth? Entry level doses are 100 mcg once or twice daily. Standard research doses are 100 to 200 mcg two to three times daily. High doses of 300 mcg produce significant hunger. Optimal injection timing is upon waking fasted, pre-workout, and at bedtime. Always inject in a fasted state for maximum GH release. ### Can GHRP-6 be combined with CJC-1295? Yes. GHRP-6 and CJC-1295 work through entirely separate receptor systems that converge at the pituitary, producing synergistic rather than additive GH output. A common combination is 100 mcg GHRP-6 plus 100 mcg CJC-1295 administered two to three times daily in a fasted state. ### What are GHRP-6 side effects? Beyond intense appetite stimulation, common side effects include fluid retention, tingling in extremities, fatigue after injection, and elevated cortisol and prolactin levels. Serious risks include pituitary desensitization with chronic use, worsened insulin resistance, and potential promotion of malignancy from elevated IGF-1. ### How long should you cycle GHRP-6? Standard cycling protocols recommend 8 to 12 weeks on followed by 8 to 12 weeks off. This prevents GHS-R1a receptor desensitization that diminishes GH response over time. Without cycling, the pituitary becomes less responsive to ghrelin receptor stimulation, reducing effectiveness while maintaining side effects. ## References 1. Pimentel-Filho FR, Ramos-Dias JC, Ninno FB, et al.. "Growth hormone responses to GH-releasing peptide (GHRP-6) in hypothyroidism." *Clin Endocrinol (Oxf)*, 1997. PMID: 9156038. https://pubmed.ncbi.nlm.nih.gov/9156038/ 2. Pandya N, DeMott-Friberg R, Engblom D, et al.. "Growth hormone (GH)-releasing peptide-6 requires endogenous hypothalamic GH-releasing hormone for maximal GH stimulation." *J Clin Endocrinol Metab*, 1998. PMID: 9543138. https://pubmed.ncbi.nlm.nih.gov/9543138/ 3. Lei T, Bhargava KK, Bhatt RR, et al.. "Growth hormone releasing peptide (GHRP-6) stimulates phosphatidylinositol (PI) turnover in human pituitary somatotroph cells." *J Mol Endocrinol*, 1995. PMID: 7772238. https://pubmed.ncbi.nlm.nih.gov/7772238/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. GHRP-6 has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/ghrp-6 --- # Hexarelin **Hexarelin (Examorelin)** Category: Growth > Potent Growth Hormone Secretagogue with Cardiac Benefits Hexarelin is one of the most potent members of the growth hormone secretagogue (GHS) family, producing GH pulses of greater magnitude than GHRP-6 or GHRP-2 at equivalent molar doses. Uniquely, it acts through both the GHS-R1a receptor (for GH release) and the CD36 receptor in cardiac tissue (for cardioprotective effects that are substantially independent of GH), making it a subject of cardiovascular research beyond its somatotropic applications. ## Key Facts - **Molecular weight:** 887.0 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/6918297) - **Molecular formula:** C47H58N12O6 (source: https://pubchem.ncbi.nlm.nih.gov/compound/6918297) - **Sequence length:** 6 amino acids (source: https://pubchem.ncbi.nlm.nih.gov/compound/6918297) - **Primary target:** Growth hormone secretagogue receptor type 1a (GHS-R1a / ghrelin receptor) (source: https://pubmed.ncbi.nlm.nih.gov/8126144/) - **Mechanism class:** Growth hormone secretagogue (GHS-R1a / ghrelin receptor agonist) (source: https://www.guidetopharmacology.org/GRAC/LigandDisplayForward?tab=biology&ligandId=1100) - **Half-life:** ~55 min (human, elimination); 120 min terminal (dog IV), ~76 min (rat IV) (source: https://pubmed.ncbi.nlm.nih.gov/8545255/) - **Route of administration:** Subcutaneous injection (IV, intranasal, and oral also studied; SC bioavailability ~77%) (source: https://pubmed.ncbi.nlm.nih.gov/8126144/) - **Regulatory status:** Not approved (research-use-only). Reached Phase II trials for GH deficiency and congestive heart failure; development discontinued, never marketed. (source: https://drugs.ncats.io/drug/09QF37C617) - **CAS number:** 140703-51-1 (source: https://pubchem.ncbi.nlm.nih.gov/compound/6918297) ## Overview Hexarelin is a synthetic hexapeptide and one of the most potent members of the growth hormone secretagogue (GHS) family. Structurally similar to GHRP-6 but modified for improved metabolic stability and receptor binding affinity, hexarelin produces GH pulses of greater magnitude than either GHRP-6 or GHRP-2 at equivalent molar doses. In preclinical studies comparing hexarelin directly to ghrelin, hexarelin demonstrated superior chemical stability and more potent GH-releasing activity, making it particularly useful as a research tool for studying the GH axis. Hexarelin exerts its biological actions through two distinct receptor populations. The first is the growth hormone secretagogue receptor type 1a (GHS-R1a), the primary receptor mediating GH release from the pituitary and the same receptor targeted by ghrelin and other GHRPs. Activation of GHS-R1a by hexarelin triggers GH secretion with downstream increases in insulin-like growth factor 1 (IGF-1). The second receptor is CD36, a scavenger receptor expressed in cardiac tissue, macrophages, and adipose tissue. CD36 is the receptor through which hexarelin exerts its cardioprotective effects, which appear to be substantially independent of GH release. This dual-receptor engagement distinguishes hexarelin from most other GH secretagogues. The cardiovascular research around hexarelin is among the most compelling in the GHS class. Multiple peer-reviewed studies have documented that hexarelin improves left ventricular function in ischemic heart failure models. Research published in Frontiers in Endocrinology demonstrated that hexarelin treatment in rats following experimental myocardial infarction increased stroke volume, cardiac output, and cardiac index while decreasing total peripheral resistance. Mechanistic studies identified that hexarelin's cardioprotection involves regulation of the interleukin-1 signaling pathway through GHS-R1a activation, as well as maintenance of normal calcium handling in cardiomyocytes during ischemia-reperfusion injury. These effects were observed even in GH-deficient models, confirming they are not secondary to GH elevation. Hexarelin has also shown beneficial effects on lipid metabolism. Research using insulin-resistant mouse models (MKR mice) found that hexarelin treatment improved lipid aberrations and reduced fat accumulation, with effects that again appeared at least partly independent of its somatotropic activity. Hexarelin is not approved by the FDA for any clinical indication and is available only as a research compound. ## Dosage Route: Subcutaneous injection, preferably in a fasted state to maximize GH pulse amplitude ### Schedule | Period | Dose | | --- | --- | | Entry level | 100 mcg, 1-2x daily (assess individual tolerance) | | Standard research | 200 mcg, 2x daily (morning fasted + evening) | | High dose | 400 mcg, 2x daily (maximum GH pulse; plateau occurs above ~2 mcg/kg) | | Combined with GHRH analog | 100 mcg hexarelin + 100 mcg CJC-1295, 2x daily | ### Reconstitution - Vial size: 5 mg - Water volume: 2.5 mL bacteriostatic water - Concentration: 2 mg/mL (2,000 mcg/mL) - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 200 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 100 mcg | 0.05 mL | 5 units | | 200 mcg | 0.10 mL | 10 units | | 400 mcg | 0.20 mL | 20 units | ### Tips - Inject in a fasted state -- elevated blood glucose and circulating fatty acids blunt GH secretion - A saturation or plateau effect is observed above approximately 2 mcg/kg in humans -- higher doses do not produce proportionally larger GH pulses - Desensitization of the GHS-R1a receptor occurs more readily with hexarelin than with some other secretagogues due to its high binding affinity - Research protocols often include cycle breaks or rotation with lower-affinity secretagogues to maintain receptor sensitivity - Monitor cortisol and prolactin in longer research protocols -- hexarelin elevates both more than ipamorelin - Inject subcutaneously, avoiding the postprandial period for maximum effectiveness ### Cycling - On period: 6-8 weeks - Off period: 4-8 weeks - Notes: Shorter cycles are recommended compared to other GHRPs due to hexarelin's higher potency and faster receptor desensitization ## Side Effects ### Common - Water retention and edema (elevated GH and IGF-1 promote renal sodium retention and extracellular fluid expansion) - Tingling or numbness in the extremities (paresthesia) -- a common GH-class effect - Fatigue or somnolence, particularly after higher doses or evening injections - Elevated cortisol and prolactin (more pronounced with hexarelin than with ipamorelin or some other GHRPs; sustained prolactin elevation may cause sexual side effects) - Appetite stimulation (less prominent than with GHRP-6 but can occur through ghrelin receptor activation) - Headache and flushing in some individuals ### Severe / Theoretical Risks - **Promotion of tumor growth**: Elevated GH and IGF-1 are mitogenic. Individuals with active malignancy or high cancer risk should not use hexarelin. - **Receptor desensitization**: Hexarelin's high potency can lead to tachyphylaxis with prolonged continuous use, diminishing GH response over time. - **Worsening insulin resistance**: GH is a counter-regulatory hormone that impairs insulin sensitivity, particularly at higher GH concentrations. - **Carpal tunnel syndrome**: Sustained IGF-1 elevation from prolonged use can cause progressive carpal tunnel syndrome. - **Hypopituitarism risk**: Theoretical risk with chronic very high-dose use based on continuous GHS-R1a suppression; not confirmed in clinical use. ### Contraindications - Active or prior malignancy (growth-promoting hormonal environment) - Diabetes mellitus or clinically significant insulin resistance - Pregnancy and lactation - Active acromegaly or elevated baseline GH/IGF-1 - Pediatric use in individuals with open growth plates without specialist supervision - Known hypersensitivity to hexarelin or formulation components ## FAQ ### What is Hexarelin and how does it differ from other GH peptides? Hexarelin is one of the most potent growth hormone secretagogues, producing GH pulses of greater magnitude than GHRP-6 or GHRP-2 at equivalent doses. Uniquely, it acts through both the GHS-R1a receptor for GH release and the CD36 receptor in cardiac tissue for cardioprotective effects independent of growth hormone. ### Does Hexarelin have heart benefits? Yes. Research demonstrates that hexarelin improves left ventricular function in ischemic heart failure models through CD36 receptor activation. It increased stroke volume, cardiac output, and cardiac index while decreasing peripheral resistance. These cardioprotective effects occur even in GH-deficient models, confirming independence from GH. ### What is the Hexarelin dosage? Entry level doses are 100 mcg once or twice daily. Standard research doses are 200 mcg twice daily. A saturation effect occurs above approximately 2 mcg/kg in humans, so higher doses do not produce proportionally larger GH pulses. Combine with GHRH analogs like CJC-1295 for synergistic effects. ### Why does Hexarelin need shorter cycles than other GH peptides? Hexarelin's high receptor binding affinity causes faster GHS-R1a desensitization than lower-affinity secretagogues. Recommended cycles are 6 to 8 weeks on followed by 4 to 8 weeks off, shorter than the 8 to 12 week cycles typical for GHRP-2 or GHRP-6. Some protocols rotate between different secretagogues. ### What are Hexarelin side effects? Common effects include water retention, tingling in extremities, fatigue, elevated cortisol and prolactin (more than ipamorelin), appetite stimulation, and headache. Hexarelin elevates cortisol and prolactin more than most other GH secretagogues, which may cause sexual side effects with sustained use. ### Is Hexarelin FDA approved? Hexarelin has not been approved by the FDA for any clinical indication and is available only as a research compound. Despite compelling cardiovascular research data and potent GH-releasing activity in published studies, no regulatory pathway has been pursued for human therapeutic approval in any major jurisdiction. ## References 1. Korbonits M, Kaltsas G, Perry LA, et al.. "The growth hormone secretagogue hexarelin stimulates the hypothalamo-pituitary-adrenal axis via arginine vasopressin." *J Clin Endocrinol Metab*, 1999. PMID: 10404825. https://pubmed.ncbi.nlm.nih.gov/10404825/ 2. Tivesten A, Bollano E, Caidahl K, et al.. "The growth hormone secretagogue hexarelin improves cardiac function in rats after experimental myocardial infarction." *Endocrinology*, 2000. PMID: 10614623. https://pubmed.ncbi.nlm.nih.gov/10614623/ 3. Mosa R, Huang L, Li H, et al.. "Hexarelin, a Growth Hormone Secretagogue, Improves Lipid Metabolic Aberrations in Nonobese Insulin-Resistant Male MKR Mice." *Endocrinology*, 2017. PMID: 28977588. https://pubmed.ncbi.nlm.nih.gov/28977588/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Hexarelin has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/hexarelin --- # MK-677 **MK-677 (Ibutamoren)** Category: Growth > Oral Growth Hormone Secretagogue MK-677 (ibutamoren) is a potent, orally active growth hormone secretagogue that selectively mimics ghrelin by binding to GHSR receptors. It produces sustained, pulsatile GH release and significant IGF-1 elevation with once-daily oral dosing. Clinical research documents 60-73% increases in IGF-1 and improvements in lean body mass. ## Key Facts - **Molecular weight:** 528.7 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/178024) - **Molecular formula:** C27H36N4O5S (source: https://pubchem.ncbi.nlm.nih.gov/compound/178024) - **Primary target:** Ghrelin receptor (growth hormone secretagogue receptor type 1a, GHSR-1a) (source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8568970/) - **Mechanism class:** Growth hormone secretagogue; selective non-peptide ghrelin receptor (GHSR-1a) agonist (source: https://www.guidetopharmacology.org/services/ligands/5867/interactions) - **Half-life:** 4-6 hours (plasma elimination half-life, measured in beagles); IGF-1 elevation sustained ~24 hours after a single oral dose (pharmacodynamic effect, not molecular elimination) (source: https://en.wikipedia.org/wiki/Ibutamoren) - **Route of administration:** Oral (by mouth) (source: https://pubmed.ncbi.nlm.nih.gov/8954023/) - **Regulatory status:** Investigational New Drug (IND); not approved by FDA for any indication or for human consumption in the United States (source: https://www.opss.org/article/performance-enhancing-substance-mk-677-ibutamoren) - **CAS number:** 159634-47-6 (free base) (source: https://pubchem.ncbi.nlm.nih.gov/compound/178024) ## Overview MK-677, also known as ibutamoren, is a potent, orally active, non-peptide growth hormone secretagogue that selectively mimics the action of ghrelin by binding to growth hormone secretagogue receptors (GHSR) in the brain and pituitary. Unlike injectable growth hormone-releasing peptides, MK-677 is active when taken orally and has a half-life of approximately 24 hours, allowing once-daily dosing. It is technically classified as a small molecule rather than a peptide, but it functions within the peptide growth hormone axis and is widely studied in the context of GH-elevating peptide therapies. The mechanism of action involves four complementary pathways: stimulation of growth hormone-releasing hormone (GHRH) production, suppression of somatostatin (the hormone that inhibits GH release), amplification of GHRH signaling at the anterior pituitary, and attenuation of somatostatin receptor signaling. The result is a sustained, physiological increase in pulsatile GH secretion, which in turn drives hepatic production of insulin-like growth factor 1 (IGF-1). A key feature of this mechanism is that pulsatility of GH secretion is preserved, in contrast to exogenous GH administration, which produces non-physiological constant elevation. Clinical research has documented the hormonal effects of MK-677 in human subjects. In a 12-month randomized trial of 563 patients receiving 25 mg orally once daily, serum IGF-1 increased by 60.1% at 6 weeks and by 72.9% at 12 months. GH secretion increased up to 97% above baseline in some study parameters. MK-677 also improved nitrogen balance in subjects undergoing diet-induced catabolism, suggesting a protein-sparing effect relevant to muscle preservation during caloric restriction. Lean body mass increased in multiple trials without corresponding changes in total fat mass or visceral fat, which distinguishes its body composition effects from those of exogenous GH. Research has also explored MK-677 in conditions associated with GH decline, including aging-related muscle wasting, hip fracture recovery, and growth hormone deficiency. A notable two-year study in healthy older adults (60 to 81 years) found significant increases in lean body mass, GH pulse amplitude, and IGF-1, though functional strength gains were modest. MK-677 remains an investigational drug (IND) in the United States and has not received FDA approval for any indication. ## Dosage Route: Oral (capsules or tablets); no reconstitution required ### Schedule | Period | Dose | | --- | --- | | Initial or conservative dosing | 5 mg/day (lower side effect burden) | | General GH support | 10 mg/day (frequently used in longer research protocols) | | Clinical trial standard | 25 mg/day (used in most published human studies) | ### Reconstitution - Vial size: N/A (oral formulation) - Water volume: N/A - Concentration: N/A - Per unit: Oral capsules or tablets; no reconstitution required ### Tips - Take orally once daily; the 24-hour half-life makes single daily dosing sufficient - Consider taking the dose at night before sleep to reduce daytime hunger from ghrelin receptor activity - Evening dosing may coincide with the natural nocturnal GH pulse - Monitor fasting blood glucose and HbA1c with prolonged use - Many research protocols limit continuous cycles to 16-24 weeks followed by an off period due to cortisol elevation and potential insulin resistance ### Cycling - On period: 16-24 weeks - Off period: Variable; off periods commonly reported in research protocols - Notes: Human research protocols have ranged from 8 weeks to 24 months. Off periods are recommended due to potential insulin resistance with prolonged continuous use. ## Side Effects ### Common - Increased appetite and hunger (significant; driven by ghrelin receptor activation) - Water retention and mild edema (ankles, hands, face) - Fatigue or lethargy, particularly in the first weeks - Elevated fasting blood glucose and reduced insulin sensitivity - Elevated cortisol levels - Tingling or numbness in extremities (carpal tunnel-like symptoms) - Increased sleep depth and duration ### Severe / Theoretical Risks - **Worsening insulin resistance**: Of particular concern in pre-diabetic or diabetic individuals. Monitor fasting glucose and HbA1c throughout the research protocol. - **Elevated IGF-1 beyond reference range**: High sustained IGF-1 levels are theoretically associated with promotion of occult malignancies. This risk is not quantified in human studies but is a class concern with GH-axis stimulation. - **Pituitary tumor growth**: MK-677 is contraindicated in individuals with active pituitary or hypothalamic tumors due to potential for promoting growth. - **Cardiac fluid retention**: Fluid retention may exacerbate heart failure or other cardiac conditions in susceptible individuals. ### Contraindications - Active or suspected malignancy (particularly IGF-1-sensitive cancers) - Diabetes mellitus or significant insulin resistance (without medical supervision) - Active pituitary or hypothalamic disease - Pregnancy or breastfeeding - Pediatric patients with open growth plates (risk of abnormal growth) ## FAQ ### What is MK-677 and how does it increase growth hormone? MK-677 (ibutamoren) is a potent, orally active growth hormone secretagogue that mimics ghrelin by binding to GHSR receptors. It stimulates GHRH production, suppresses somatostatin, and amplifies pituitary GH signaling. Clinical research documents 60 to 73% increases in IGF-1 with preserved pulsatile GH secretion. ### Is MK-677 a peptide or a SARM? MK-677 is technically a small molecule, not a peptide or a SARM. It functions within the growth hormone axis by mimicking ghrelin at the GHSR receptor. It is often categorized alongside peptide GH therapies because of its overlapping applications, but its oral bioavailability and 24-hour half-life distinguish it structurally. ### What is the best MK-677 dosage? The clinical trial standard dose is 25 mg once daily, which produced a 60 to 73% increase in IGF-1 in published studies. Conservative users start at 5 to 10 mg daily to reduce side effects. Taking the dose at night before sleep can reduce daytime hunger and coincide with the natural nocturnal GH pulse. ### Does MK-677 cause insulin resistance? Yes. Elevated fasting blood glucose and reduced insulin sensitivity are documented side effects of MK-677, driven by GH's antagonistic effects on insulin signaling. Monitor fasting glucose and HbA1c with prolonged use. This risk is amplified in pre-diabetic individuals and represents the primary metabolic concern. ### What are MK-677 side effects? Common effects include significantly increased appetite and hunger, water retention and edema, fatigue, elevated fasting blood glucose, elevated cortisol, tingling in extremities, and increased sleep depth. The appetite stimulation from ghrelin receptor activation is often the most noticeable and challenging side effect to manage. ### How long can you take MK-677? Published human research protocols range from 8 weeks to 24 months. Many protocols limit continuous cycles to 16 to 24 weeks followed by an off period due to cortisol elevation and potential insulin resistance accumulation. A two-year study in older adults showed sustained IGF-1 elevation throughout treatment. ## References 1. Chapman IM, Bach MA, Van Cauter E, et al.. "Stimulation of the growth hormone (GH)-insulin-like growth factor I axis by daily oral administration of a GH secretogogue (MK-677) in healthy elderly subjects." *J Clin Endocrinol Metab*, 1996. PMID: 8954023. https://pubmed.ncbi.nlm.nih.gov/8954023/ 2. Nass R, Pezzoli SS, Oliveri MC, et al.. "Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trial." *Ann Intern Med*, 2008. PMID: 18981485. https://pubmed.ncbi.nlm.nih.gov/18981485/ 3. Murphy MG, Plunkett LM, Gertz BJ, et al.. "MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism." *J Clin Endocrinol Metab*, 1998. PMID: 9467534. https://pubmed.ncbi.nlm.nih.gov/9467534/ 4. Sevigny JJ, Ryan JM, van Dyck CH, et al.. "Growth hormone secretagogue MK-677: no clinical effect on AD progression in a randomized trial." *Neurology*, 2008. PMID: 19015485. https://pubmed.ncbi.nlm.nih.gov/19015485/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. MK-677 (ibutamoren) has not been approved by the FDA for any medical condition and remains an investigational compound. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/mk-677 --- # CJC-1295 DAC **CJC-1295 DAC (Drug Affinity Complex)** Category: Growth > Long-Acting GHRH Analog for Growth Hormone Support CJC-1295 DAC is a long-acting synthetic GHRH analog that covalently binds to serum albumin after injection, extending its half-life to 6-8 days. A single subcutaneous injection produces 2- to 10-fold GH elevation sustained for 6 or more days, and IGF-1 remains elevated for 9-11 days, with preserved pulsatile GH secretion throughout. ## Key Facts - **Molecular weight:** 3647.25 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/91971820) - **Molecular formula:** C165H269N47O46 (source: https://pubchem.ncbi.nlm.nih.gov/compound/91971820) - **Sequence length:** 30 amino acids (tetrasubstituted GHRH(1-29) core plus Lys30 bearing the maleimidopropionyl DAC linker) (source: https://pubmed.ncbi.nlm.nih.gov/15817669/) - **Primary target:** Growth hormone-releasing hormone receptor (GHRHR) on anterior pituitary somatotrophs (source: https://pubmed.ncbi.nlm.nih.gov/16352683/) - **Mechanism class:** Long-acting GHRH analog / growth hormone secretagogue (GHRH receptor agonist); albumin-binding via Drug Affinity Complex (source: https://pubmed.ncbi.nlm.nih.gov/15817669/) - **Half-life:** 5.8-8.1 days (single-dose elimination half-life in healthy adults; commonly cited as ~6-8 days) (source: https://pubmed.ncbi.nlm.nih.gov/16352683/) - **Route of administration:** Subcutaneous injection (source: https://pubmed.ncbi.nlm.nih.gov/16352683/) - **Regulatory status:** Not approved by FDA or EMA for any indication; investigational compound whose clinical development (Phase II, ConjuChem) was discontinued in 2006; research-use-only / not approved for human use (source: https://clinicaltrials.gov/study/NCT00267527) - **CAS number:** 446262-90-4 (source: https://pubchem.ncbi.nlm.nih.gov/compound/91971820) ## Overview CJC-1295 DAC (Drug Affinity Complex) is a long-acting synthetic analog of growth hormone-releasing hormone (GHRH), developed by ConjuChem Biotechnologies. It was engineered to address the primary limitation of native GHRH and its earlier analogs: rapid degradation by dipeptidyl peptidase IV (DPP-IV), which gives natural GHRH a half-life of only 7 minutes in the circulation. CJC-1295 DAC resolves this through two complementary modifications: four amino acid substitutions that render the peptide backbone resistant to DPP-IV cleavage, and the attachment of a Drug Affinity Complex (DAC) molecule that enables covalent binding to circulating serum albumin after injection. The albumin-binding mechanism is the defining pharmacological feature of the DAC formulation. Once CJC-1295 DAC is injected subcutaneously, the DAC moiety undergoes a bioconjugation reaction with endogenous albumin through a maleimide-thiol linkage. Because albumin has a circulating half-life of approximately 19 days, the conjugated peptide is effectively shielded from renal clearance and proteolytic degradation, extending the functional half-life of CJC-1295 DAC to 6 to 8 days in humans. This is in marked contrast to CJC-1295 without DAC (also called Modified GRF 1-29), which has a half-life of approximately 30 minutes. The clinical pharmacology of CJC-1295 DAC was characterized in a Phase II human study published in the Journal of Clinical Endocrinology and Metabolism (2006). After a single subcutaneous injection in healthy adults, mean plasma GH concentrations increased 2- to 10-fold and remained elevated for 6 days or more, depending on dose. Mean plasma IGF-1 concentrations rose 1.5- to 3-fold and remained elevated for 9 to 11 days. Critically, pulsatility of GH secretion was preserved throughout the sustained stimulation period, a physiologically important finding that distinguishes CJC-1295 DAC from exogenous GH administration. Multiple-dose studies demonstrated cumulative IGF-1 elevation, with levels remaining elevated for up to 28 days following a series of weekly injections. Sustained GHRH receptor stimulation from long-acting analogs like CJC-1295 DAC is sometimes described as producing a 'GH bleed' effect: a continuous low-level elevation of GH between pulsatile peaks, rather than the sharp pulsatile pattern of native GH secretion. Research applications have focused on aging-related GH decline, body composition, sleep quality, and recovery. CJC-1295 DAC is not FDA-approved for any indication and remains a research compound. It is frequently used in combination with GHRP-class peptides or ghrelin mimetics such as ipamorelin or MK-677 to produce synergistic GH release through complementary pituitary pathways. ## Dosage Route: Subcutaneous injection, once weekly ### Schedule | Period | Dose | | --- | --- | | Conservative research starting dose | 1 mg/week | | Standard research protocol | 2 mg/week | | Higher-end research protocols | 2-4 mg/week | ### Reconstitution - Vial size: 5 mg - Water volume: 2.5 mL bacteriostatic water - Concentration: 2 mg/mL - Per unit: For a 2 mg weekly dose, draw 1 mL (100 units on a U-100 syringe) ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 1 mg | 0.5 mL | 50 units | | 2 mg | 1 mL | 100 units | | 4 mg | 2 mL | 200 units | ### Tips - Swirl gently to dissolve; do not shake the vial - Refrigerate reconstituted solution and use within 30 days; protect from light - Administer once weekly; a consistent injection day is sufficient due to the long half-life - Some protocols administer CJC-1295 DAC in the evening to coincide with natural GH pulse timing during sleep - CJC-1295 DAC is frequently paired with ipamorelin (100-300 mcg per injection, 1-3 times daily) for synergistic GH release - Human Phase II reference dose: approximately 30-60 mcg/kg as a single subcutaneous injection - Monitor fasting glucose and consider periodic IGF-1 levels during use ## Side Effects ### Common - Water retention and mild edema (hands, ankles, face): driven by elevated IGF-1 and GH activity on sodium and water handling - Injection site reactions: mild redness, swelling, or discomfort at the subcutaneous site - Fatigue or somnolence: particularly in the days following injection during peak GH/IGF-1 elevation - Headache - Tingling or numbness in hands or feet (carpal tunnel-like symptoms): associated with GH-driven fluid retention around nerve sheaths - Flushing ### Severe / Theoretical Risks - **Elevated IGF-1 beyond physiological reference range**: Sustained supraphysiological IGF-1 carries theoretical risk of promoting growth of occult malignancies. This is a class-level concern for all GH-axis stimulating agents. - **Acromegaloid effects with prolonged high-dose use**: Jaw changes, hand and foot enlargement, and joint pain may develop with long-term supraphysiological GH elevation. - **Insulin resistance**: GH elevation counteracts insulin action. Monitor fasting glucose and consider HbA1c with long-term use, particularly in individuals with metabolic risk factors. - **Pituitary desensitization**: Theoretical concern with continuous GHRH receptor stimulation from the 'GH bleed' effect. Pulsatility preservation in published data partially mitigates this concern. - **Hypersensitivity**: Rare anaphylactic reactions to peptide components have been reported in the broader peptide class. ### Contraindications - Active malignancy or personal history of IGF-1-sensitive cancers - Active pituitary or hypothalamic disease - Uncontrolled diabetes mellitus - Pregnancy or breastfeeding - Pediatric use in individuals with open growth plates (risk of disproportionate growth) - Known hypersensitivity to GH, GHRH, or their analogs ## FAQ ### What is CJC-1295 DAC and how does it work? CJC-1295 DAC is a long-acting GHRH analog that covalently binds to serum albumin after injection through its Drug Affinity Complex moiety. This extends its half-life to 6 to 8 days, compared to 30 minutes for CJC-1295 without DAC. A single injection produces elevated GH for 6 or more days. ### What is the difference between CJC-1295 with and without DAC? CJC-1295 without DAC (Modified GRF 1-29) has a half-life of approximately 30 minutes and produces acute GH pulses requiring multiple daily injections. CJC-1295 DAC binds to albumin for a 6 to 8 day half-life, enabling once-weekly dosing with sustained GH elevation and cumulative IGF-1 increases. ### What is the CJC-1295 DAC dosage? Conservative starting dose is 1 mg per week. Standard research protocols use 2 mg weekly. Higher-end protocols use 2 to 4 mg weekly. A consistent weekly injection day is sufficient due to the long half-life. Some protocols administer in the evening to coincide with natural nocturnal GH pulse timing. ### How long does it take for CJC-1295 DAC to show results? GH elevation begins within hours of the first injection. IGF-1 rises 1.5 to 3 fold and remains elevated for 9 to 11 days after a single dose. Multiple weekly injections produce cumulative IGF-1 elevation over 28 days. Body composition and recovery improvements typically become noticeable over 4 to 12 weeks. ### What are CJC-1295 DAC side effects? Common effects include water retention, injection site reactions, fatigue, headache, tingling in hands or feet from GH-driven fluid retention, and flushing. Serious risks include elevated IGF-1 beyond reference ranges, acromegaloid effects with prolonged high-dose use, insulin resistance, and theoretical cancer promotion. ### Can CJC-1295 DAC be combined with Ipamorelin? Yes. CJC-1295 DAC is frequently paired with ipamorelin (100 to 300 mcg per injection, 1 to 3 times daily) for synergistic GH release. CJC-1295 DAC stimulates through the GHRH pathway while ipamorelin acts through the ghrelin receptor, producing complementary amplification at the pituitary level. ## References 1. Jette L, Leger R, Thibaudeau K, et al.. "Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats: identification of CJC-1295 as a long-lasting GRF analog." *Endocrinology*, 2005. PMID: 15817669. https://pubmed.ncbi.nlm.nih.gov/15817669/ 2. Teichman SL, Neale A, Lawrence B, et al.. "Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults." *J Clin Endocrinol Metab*, 2006. PMID: 16352683. https://pubmed.ncbi.nlm.nih.gov/16352683/ 3. Ionescu M, Frohman LA. "Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog." *J Clin Endocrinol Metab*, 2006. PMID: 17018654. https://pubmed.ncbi.nlm.nih.gov/17018654/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. CJC-1295 DAC has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/cjc-1295-dac --- # Liraglutide **Liraglutide (Saxenda / Victoza)** Category: Weight Loss > GLP-1 Receptor Agonist for Weight Loss Liraglutide is a synthetic GLP-1 analogue with 97% sequence homology to native GLP-1, modified with a C16 fatty acid side chain to extend its half-life to approximately 13 hours for once-daily dosing. FDA-approved as Saxenda (3.0 mg) for chronic weight management and as Victoza (1.8 mg) for type 2 diabetes, it reduces appetite and food intake through central GLP-1 receptor activation in hypothalamic and brainstem appetite centers. ## Key Facts - **Molecular weight:** 3751.26 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/16134956) - **Molecular formula:** C172H265N43O51 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16134956) - **Sequence length:** 31 amino acids (source: https://www.ncbi.nlm.nih.gov/books/NBK608007/) - **Primary target:** GLP-1 receptor (glucagon-like peptide-1 receptor) (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3946d389-0926-4f77-a708-0acb8153b143) - **Mechanism class:** GLP-1 receptor agonist (incretin mimetic) (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3946d389-0926-4f77-a708-0acb8153b143) - **Half-life:** approximately 13 hours (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3946d389-0926-4f77-a708-0acb8153b143) - **Route of administration:** Subcutaneous injection, once daily (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3946d389-0926-4f77-a708-0acb8153b143) - **Regulatory status:** FDA approved: Victoza (type 2 diabetes, Jan 2010) and Saxenda (chronic weight management, Dec 2014) (source: https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-weight-management-drug-patients-aged-12-and-older) - **CAS number:** 204656-20-2 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16134956) ## Overview Liraglutide is a synthetic analogue of glucagon-like peptide-1 (GLP-1), a naturally occurring incretin hormone secreted by intestinal L-cells in response to nutrient ingestion. The engineered compound shares 97% amino acid sequence homology with endogenous GLP-1 but incorporates a C16 fatty acid side chain attached via a glutamate linker. This structural modification allows liraglutide to bind to plasma albumin, dramatically extending its half-life from approximately 2 minutes for native GLP-1 to approximately 13 hours for liraglutide, enabling once-daily subcutaneous dosing. Liraglutide exerts its effects by binding to and activating the GLP-1 receptor, a G protein-coupled receptor found on pancreatic beta cells, in multiple regions of the brain, in the gastrointestinal tract, and in the cardiovascular system. At the pancreas, GLP-1 receptor activation stimulates glucose-dependent insulin secretion and suppresses glucagon release, producing glycemic control without hypoglycemia in the fasting state. In the brain, particularly in hypothalamic and brainstem regions governing appetite and energy homeostasis, GLP-1 receptor activation reduces appetite and increases satiety. Research has confirmed that weight loss with liraglutide is driven primarily by reduced energy intake rather than by increased energy expenditure. The SCALE clinical program, a series of phase III randomized controlled trials, established liraglutide 3.0 mg daily (marketed as Saxenda for obesity) as an effective anti-obesity pharmacotherapy. In the landmark SCALE Obesity and Prediabetes trial published in the New England Journal of Medicine, participants receiving liraglutide 3.0 mg lost an average of 8.4 kg (approximately 8% of body weight) over 56 weeks, compared to 2.8 kg in the placebo group. More than 60% of liraglutide-treated participants achieved at least 5% weight loss. Additional SCALE trials demonstrated benefits in glycemic outcomes, cardiovascular risk markers, and weight maintenance after prior lifestyle intervention. Liraglutide was FDA-approved as Victoza (1.2 mg and 1.8 mg) for type 2 diabetes mellitus in 2010 and as Saxenda (3.0 mg) for chronic weight management in adults with obesity or overweight with at least one weight-related comorbidity in 2014. These are among the most firmly established regulatory approvals for any peptide compound currently available. ## Dosage Route: Subcutaneous injection, once daily (any time, with or without food) ### Schedule | Period | Dose | | --- | --- | | Week 1 | 0.6 mg daily (tolerability titration) | | Week 2 | 1.2 mg daily (intermediate titration) | | Week 3 | 1.8 mg daily (intermediate titration) | | Week 4 | 2.4 mg daily (near-maintenance) | | Week 5 onward | 3.0 mg daily (full therapeutic dose for weight loss) | ### Reconstitution - Vial size: Supplied as pre-filled multi-dose injection pen (18 mg/3 mL) -- no reconstitution required - Water volume: N/A (pre-filled pen) - Concentration: 6 mg/mL - Per unit: Each 0.5 mg dose = 0.083 mL from the pre-filled pen ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 0.6 mg | 0.10 mL | Pen dial to 0.6 mg mark | | 1.8 mg | 0.30 mL | Pen dial to 1.8 mg mark | | 3.0 mg | 0.50 mL | Pen dial to 3.0 mg mark (maximum approved dose) | ### Tips - A gradual dose escalation is mandatory to minimize gastrointestinal side effects, particularly nausea - For type 2 diabetes management, the approved maintenance doses are 1.2 mg or 1.8 mg daily - For weight management (Saxenda), the target dose is 3.0 mg daily - If a patient cannot tolerate at least 1.2 mg after the escalation period, discontinuation is recommended - Preferred injection sites: abdomen, thigh, or upper arm; do not inject into areas of lipodystrophy - Rotate injection sites with each injection ### Cycling - On period: Indefinite (chronic weight management) - Off period: Discontinue if 5% weight loss is not achieved after 12 weeks at 3.0 mg - Notes: Liraglutide is indicated for chronic use; weight regain typically occurs after discontinuation ## Side Effects ### Common - Nausea (up to 40% of patients; most prominent during dose escalation, typically attenuates over several weeks) - Vomiting and diarrhea during titration phase (generally self-limiting) - Constipation (approximately 10-15% of users) - Injection site reactions (redness, bruising, transient discomfort) - Headache and fatigue, particularly during early treatment - Elevated heart rate (mean increase of approximately 2-3 beats per minute, consistent GLP-1 class finding) ### Severe / Theoretical Risks - **Pancreatitis**: Cases of acute pancreatitis, including fatal and non-fatal hemorrhagic or necrotizing pancreatitis, have been reported. Liraglutide should be discontinued immediately if pancreatitis is suspected. - **Thyroid C-cell tumors**: Liraglutide caused dose-dependent and treatment-duration-dependent thyroid C-cell tumors in animal studies. Liraglutide carries a black box warning for this risk and is contraindicated in individuals with a personal or family history of medullary thyroid carcinoma (MTC) or MEN 2. - **Gallbladder disease**: Rapid weight loss from any cause increases gallstone risk; liraglutide-related weight loss is no exception. - **Renal impairment**: Acute kidney injury and worsening of pre-existing renal disease have been reported, often in the setting of severe dehydration from vomiting or diarrhea. - **Hypoglycemia**: Most likely when combined with insulin or sulfonylureas; not common with liraglutide monotherapy. ### Contraindications - Personal or family history of medullary thyroid carcinoma (MTC) - Multiple Endocrine Neoplasia syndrome type 2 (MEN 2) - Prior serious hypersensitivity reaction to liraglutide - Pregnancy (weight loss is not recommended during pregnancy; limited human safety data) - Type 1 diabetes or diabetic ketoacidosis (not indicated) - History of pancreatitis (use with caution or avoid) ## FAQ ### What is Liraglutide and how does it cause weight loss? Liraglutide is a synthetic GLP-1 analog with a 13-hour half-life enabling once-daily dosing. It reduces appetite through central GLP-1 receptor activation in hypothalamic appetite centers. The SCALE trial showed participants lost an average 8.4 kg (8% body weight) over 56 weeks at the 3.0 mg dose. ### What is the difference between Saxenda and Victoza? Both contain liraglutide but at different doses for different indications. Victoza (1.2 to 1.8 mg) is FDA-approved for type 2 diabetes glycemic control. Saxenda (3.0 mg) is FDA-approved for chronic weight management in adults with obesity or overweight with at least one weight-related comorbidity. ### How do you dose Liraglutide for weight loss? Liraglutide requires gradual dose escalation to minimize GI side effects: 0.6 mg daily in week 1, increasing by 0.6 mg weekly until reaching the full 3.0 mg therapeutic dose by week 5. If 5% weight loss is not achieved after 12 weeks at 3.0 mg, discontinuation is recommended. ### What are the most common Liraglutide side effects? Nausea affects up to 40% of patients, mostly during dose escalation, and typically attenuates over several weeks. Other common effects include vomiting, diarrhea, constipation, injection site reactions, headache, and a mean heart rate increase of approximately 2 to 3 beats per minute. ### Does Liraglutide cause thyroid cancer? Liraglutide caused dose-dependent thyroid C-cell tumors in rodent studies and carries a black box warning for this risk. It is contraindicated in individuals with personal or family history of medullary thyroid carcinoma or MEN 2 syndrome. No confirmed human thyroid cancer cases have been attributed to liraglutide. ### How does Liraglutide compare to Semaglutide? Both are GLP-1 receptor agonists, but semaglutide produces greater average weight loss (approximately 15% vs 8%) and requires only weekly dosing compared to liraglutide's daily injections. Liraglutide has a longer track record of safety data and established cardiovascular benefit from the LEADER trial. ## References 1. Pi-Sunyer X, Astrup A, Fujioka K, et al.. "A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management." *N Engl J Med*, 2015. PMID: 26132939. https://pubmed.ncbi.nlm.nih.gov/26132939/ 2. Marso SP, Daniels GH, Tanaka K, et al.. "Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes." *N Engl J Med*, 2016. PMID: 27295427. https://pubmed.ncbi.nlm.nih.gov/27295427/ 3. Davies MJ, Bergenstal R, Bode B, et al.. "Efficacy of Liraglutide for Weight Loss Among Patients With Type 2 Diabetes: The SCALE Diabetes Randomized Clinical Trial." *JAMA*, 2015. PMID: 26284720. https://pubmed.ncbi.nlm.nih.gov/26284720/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Liraglutide is FDA-approved under specific brand names for specific indications; use outside those approved indications may be off-label. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/liraglutide --- # Adipotide **Adipotide (FTPP -- Fat-Targeted Proapoptotic Peptide)** Category: Weight Loss > Vascular-Targeting Peptide for Fat-Specific Weight Loss Adipotide (FTPP) is a synthetic peptidomimetic compound with a dual-domain architecture: a homing sequence that binds selectively to blood vessels supplying white adipose tissue, and a proapoptotic KLAKLAK domain that destroys those vessels, causing fat tissue to undergo apoptosis and be reabsorbed. In obese rhesus monkeys, 28 days of treatment produced approximately 11% body weight reduction with improved insulin sensitivity. ## Key Facts - **Molecular weight:** 2557.2 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/163360068/property/MolecularFormula,MolecularWeight/JSON) - **Molecular formula:** C111H206N36O28S2 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/163360068/property/MolecularFormula,MolecularWeight/JSON) - **Sequence length:** 25 amino acids (source: https://pubmed.ncbi.nlm.nih.gov/22072637/) - **Primary target:** Prohibitin (and annexin A2/ANXA2) on the endothelium of blood vessels supplying white adipose tissue (source: https://pubmed.ncbi.nlm.nih.gov/15133506/) - **Mechanism class:** Ligand-directed proapoptotic peptidomimetic (adipose vasculature-targeting, KLAKLAK mitochondrial-disrupting) (source: https://pubmed.ncbi.nlm.nih.gov/22072637/) - **Route of administration:** Subcutaneous injection (source: https://pubmed.ncbi.nlm.nih.gov/22072637/) - **Regulatory status:** Investigational; not FDA-approved for any indication. Reached Phase 1 (Arrowhead, obese cancer patients, first patient dosed 2012); clinical development discontinued as of 2019. (source: https://en.wikipedia.org/wiki/Prohibitin-targeting_peptide_1) - **CAS number:** 859216-15-2 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/163360068/synonyms/JSON) ## Overview Adipotide, formally designated FTPP (Fat-Targeted Proapoptotic Peptide), is a synthetic peptidomimetic compound engineered with a dual-domain architecture. One domain functions as a homing sequence that binds selectively to receptors expressed on the endothelial cells of blood vessels supplying white adipose tissue. The second domain is a proapoptotic sequence derived from the mitochondrial protein KLAKLAK, which initiates programmed cell death in the targeted cells once the compound has been delivered to the adipose vasculature. Through this ligand-directed mechanism, Adipotide selectively destroys the blood supply to white fat, causing the adipose tissue to undergo apoptosis and be reabsorbed. The selectivity of Adipotide's homing sequence depends on prohibitin, a receptor that is highly enriched on the vasculature of white adipose tissue. Research published in Science Translational Medicine described the compound's mechanism and initial animal results. In subsequent primate research, obese rhesus monkeys treated with Adipotide for 28 days lost an average of 11% of their body weight, experienced significant reductions in waist circumference and body mass index, and showed marked improvements in insulin resistance. These results were notable for representing some of the most targeted fat-loss results observed in a non-human primate model. The compound's mechanism differs fundamentally from systemic anti-obesity agents. Rather than altering appetite, metabolic rate, or nutrient absorption, Adipotide physically eliminates the vascular infrastructure that maintains white fat depots. Metabolic improvements including increased insulin sensitivity and reduced fasting glucose levels were observed within 2 to 3 days of treatment initiation in murine models, preceding significant weight loss, suggesting direct metabolic effects beyond fat reduction. Arrowhead Pharmaceuticals initiated a Phase 1 clinical trial in humans to evaluate safety, tolerability, and preliminary efficacy in obese cancer patients. Adipotide remains an experimental compound with no approved human indications. It is available only as a research-use compound and is not approved or intended for self-administration. ## Dosage Route: Subcutaneous injection, once daily for defined treatment periods ### Schedule | Period | Dose | | --- | --- | | Obese mice (preclinical) | Approximately 2.5 mg/kg/day SQ for 28 days | | Obese rhesus monkeys (preclinical) | Approximately 0.3-1.0 mg/kg/day SQ for 28 days | | Human Phase 1 (escalation) | Multiple ascending dose levels for 28 days (safety/tolerability evaluation only) | ### Reconstitution - Vial size: Variable (research vials) - Water volume: Bacteriostatic water for injection - Concentration: Variable based on vial size and research protocol - Per unit: No established human therapeutic dose -- no human dose has been validated through completed clinical trials ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | Preclinical only | Per body weight calculation | No validated human dosing exists | ### Tips - No human dose has been established as safe and effective through completed clinical trials - Translating animal doses to human equivalents is unreliable for this compound due to differences in adipose vascular biology across species - Any use outside a controlled clinical trial constitutes unvalidated self-experimentation - Store reconstituted peptide refrigerated at 2-8 degrees Celsius and use within 30 days - Renal function monitoring is essential given nephrotoxicity signals from primate studies ## Side Effects ### Common - Injection site reactions (redness, pain, and swelling at the subcutaneous administration site) - Transient elevation in kidney function markers (creatinine, BUN) observed in primate studies - Fatigue and general malaise, particularly during the early treatment period - Thirst and increased fluid intake as compensatory responses to metabolic changes ### Severe / Theoretical Risks - **Nephrotoxicity**: The most significant safety concern identified in primate studies. Kidney injury markers were elevated in treated monkeys, and kidney histology showed changes consistent with acute tubular stress. Renal function monitoring is essential in any research context. - **Uncontrolled fat apoptosis**: The extent of vascular targeting in humans is not fully characterized. Effects beyond white adipose tissue vasculature cannot be ruled out. - **Metabolic disturbances from rapid fat mobilization**: Sudden release of free fatty acids and other adipokines from dying fat tissue may cause acute metabolic disruptions, particularly in individuals with pre-existing metabolic syndrome. - **Unknown long-term consequences**: Phase 1 clinical data in humans remains limited. Long-term effects are not known. ### Contraindications - Pre-existing renal disease or impaired kidney function - Pregnancy and breastfeeding - Active malignancy (proapoptotic mechanisms may have unintended effects on other tissues) - Pediatric use - Any condition in which rapid fat loss would be medically contraindicated - Individuals with known allergy to any component of the formulation ## FAQ ### What is Adipotide and how does it destroy fat? Adipotide (FTPP) is a synthetic peptide with dual-domain architecture: a homing sequence that binds selectively to blood vessels supplying white fat tissue, and a proapoptotic KLAKLAK domain that destroys those vessels. This causes fat tissue to undergo programmed cell death and be reabsorbed by the body. ### How much weight did monkeys lose on Adipotide? In a published study, obese rhesus monkeys treated with Adipotide for 28 days lost an average of 11% body weight, experienced significant reductions in waist circumference and BMI, and showed marked improvements in insulin resistance. Metabolic improvements appeared within 2 to 3 days, before significant weight loss occurred. ### Is Adipotide safe for humans? Adipotide safety in humans is not established. Arrowhead Pharmaceuticals initiated a Phase 1 trial in obese cancer patients, but completed human safety data are limited. The most significant concern from primate studies is nephrotoxicity, with kidney injury markers elevated in treated monkeys requiring renal function monitoring. ### What are Adipotide side effects? Known effects from animal studies include elevated kidney function markers (creatinine, BUN), injection site reactions, fatigue, and increased thirst. The most serious concern is nephrotoxicity with kidney histology showing acute tubular stress. Rapid fat mobilization may also cause acute metabolic disruptions from free fatty acid release. ### Can you buy Adipotide for personal use? Adipotide is available from some research peptide vendors, but no human dose has been validated through completed clinical trials. Translating animal doses to human equivalents is unreliable for this compound. Any use outside a controlled clinical trial constitutes unvalidated self-experimentation with significant kidney risk. ### How does Adipotide differ from other weight loss peptides? Unlike GLP-1 agonists that suppress appetite or metabolic compounds that increase energy expenditure, Adipotide physically eliminates the vascular infrastructure maintaining white fat depots. This mechanism is fundamentally different from all other anti-obesity approaches and produces direct, targeted fat tissue destruction. ## References 1. Barnhart KF, Christianson DR, Hanley PW, et al.. "A peptidomimetic targeting white fat causes weight loss and improved insulin resistance in obese monkeys." *Sci Transl Med*, 2011. PMID: 22072637. https://pubmed.ncbi.nlm.nih.gov/22072637/ 2. Kolonin MG, Saha PK, Chan L, et al.. "Reversal of obesity by targeted ablation of adipose tissue." *Nat Med*, 2004. PMID: 15133506. https://pubmed.ncbi.nlm.nih.gov/15133506/ 3. Kim DH, Woods SC, Seeley RJ. "Peptide designed to elicit apoptosis in adipose tissue endothelium reduces food intake and body weight." *Diabetes*, 2010. PMID: 20103704. https://pubmed.ncbi.nlm.nih.gov/20103704/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Adipotide (FTPP) has not been approved by the FDA for any medical condition and remains an experimental research compound. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/adipotide --- # Cagrilintide **Cagrilintide (Long-Acting Amylin Analog)** Category: Weight Loss > Long-Acting Amylin Analog for Weight Loss Cagrilintide is a long-acting amylin analog developed by Novo Nordisk as a once-weekly injectable for the treatment of obesity. Phase 2 monotherapy data showed up to 11.8% body weight reduction at 68 weeks. In combination with semaglutide (CagriSema), the REDEFINE 1 trial demonstrated a mean 20.4% body weight reduction over 68 weeks. Cagrilintide is not currently FDA-approved. ## Key Facts - **Molecular weight:** 4409 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/171397054/property/MolecularWeight,MolecularFormula/JSON) - **Molecular formula:** C194H312N54O59S2 (source: https://pubchem.ncbi.nlm.nih.gov/compound/171397054) - **Sequence length:** 37 amino acids (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/171397054/synonyms/JSON) - **Primary target:** Amylin receptors and calcitonin receptor (calcitonin family receptors) (source: https://www.guidetopharmacology.org/GRAC/LigandDisplayForward?ligandId=13768) - **Mechanism class:** Long-acting amylin analog; nonselective amylin/calcitonin receptor agonist (source: https://www.guidetopharmacology.org/GRAC/LigandDisplayForward?ligandId=13768) - **Half-life:** 159-195 h (approximately 7-8 days) (source: https://pubmed.ncbi.nlm.nih.gov/33894838/) - **Route of administration:** Subcutaneous injection, once weekly (source: https://pubmed.ncbi.nlm.nih.gov/33894838/) - **Regulatory status:** Investigational; not FDA-approved. CagriSema (cagrilintide + semaglutide) NDA submitted to FDA Dec 18, 2025; decision expected ~Oct 2026. (source: https://www.drugs.com/history/cagrisema.html) - **CAS number:** 1415456-99-3 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/171397054/synonyms/JSON) ## Overview Cagrilintide is a long-acting amylin analog developed by Novo Nordisk as a once-weekly injectable for the treatment of obesity. Amylin is a peptide hormone co-secreted with insulin from pancreatic beta cells; it plays a key role in regulating satiety by acting on homeostatic and hedonic regions of the brain, slowing gastric emptying, and suppressing glucagon release. Cagrilintide replicates and substantially extends these effects through modifications that increase its half-life and receptor binding stability compared to native amylin. Phase 2 data published in The Lancet (2021) established the dose-ranging profile of cagrilintide as monotherapy, demonstrating up to 10.8% body weight reduction over 26 weeks compared to 3.0% with placebo. Monotherapy results at 68 weeks showed an average body weight reduction of 11.8% versus 3.0% for placebo, establishing clinical meaningfulness even before combination therapy was explored. The most compelling data comes from the CagriSema combination program, pairing cagrilintide with the GLP-1 receptor agonist semaglutide. The REDEFINE 1 trial, published in the New England Journal of Medicine, showed a mean body weight reduction of 20.4% over 68 weeks for the combination group versus 3.0% for placebo. Sixty percent of participants achieved at least 20% weight loss, and 23% lost 30% or more of body weight. These results reflect an additive mechanism: cagrilintide acts on amylin receptors while semaglutide acts on GLP-1 receptors, producing complementary appetite suppression across different neural circuits. Cagrilintide is not currently FDA-approved for any indication as of early 2026 and remains under investigation. Its use outside of clinical trials is considered off-label and investigational. All research and clinical interest is directed at understanding how amylin-pathway activation can complement existing GLP-1-based therapies for sustainable obesity management. ## Dosage Route: Subcutaneous injection, once weekly ### Schedule | Period | Dose | | --- | --- | | Weeks 1-6 (escalation) | 0.3 -- 0.6 -- 1.2 -- 2.4 -- 4.5 mg once weekly | | Weeks 7-26 (treatment) | Maintenance dose based on tolerability | ### Reconstitution - Vial size: Varies by supplier - Water volume: Bacteriostatic water (0.9% benzyl alcohol) per vial labeling - Concentration: Per vial-specific labeling - Per unit: Varies by reconstitution volume ### Tips - Administer subcutaneously once weekly; the extended half-life supports once-weekly dosing without daily injections - The dose escalation protocol is designed to minimize gastrointestinal side effects during initiation - In the phase 2 monotherapy trial, the 2.4 mg dose was identified as the optimal balance of efficacy and tolerability - Reconstitute lyophilized powder with bacteriostatic water using standard aseptic technique; follow vial-specific labeling ## Side Effects ### Common - Nausea (most common, particularly during dose escalation) - Vomiting - Diarrhea - Constipation - Abdominal discomfort or pain - Decreased appetite (expected pharmacological effect) - Injection site reactions (redness, bruising, local irritation) - Fatigue, especially early in treatment ### Severe / Theoretical Risks - **Pancreatitis**: Risk signal consistent with other amylin/GLP-1 class agents; discontinue if pancreatitis is suspected. - **Severe dehydration**: Can occur secondary to prolonged vomiting or diarrhea, particularly early in treatment. - **Gallbladder disease**: Cholelithiasis observed at higher rates in significant weight loss trials across the GLP-1 class. - **Hypoglycemia**: Particularly if combined with insulin secretagogues or insulin. ### Contraindications - Personal or family history of medullary thyroid carcinoma (risk extrapolated from GLP-1 class data) - Multiple endocrine neoplasia syndrome type 2 (MEN 2) - Known hypersensitivity to cagrilintide or any component of the formulation - Pregnancy or breastfeeding (weight loss pharmacotherapy not indicated) - Type 1 diabetes (insufficient data) - Severe renal or hepatic impairment (clinical data limited) ## FAQ ### What is Cagrilintide and how does it work? Cagrilintide is a long-acting amylin analog developed by Novo Nordisk as a once-weekly injectable for obesity treatment. Amylin is a hormone co-secreted with insulin that regulates satiety, slows gastric emptying, and suppresses glucagon. Cagrilintide extends these effects through modifications increasing its half-life and receptor stability. ### How much weight can you lose with Cagrilintide? Phase 2 monotherapy data showed up to 11.8% body weight reduction at 68 weeks. Combined with semaglutide as CagriSema in the REDEFINE 1 trial, participants achieved a mean 20.4% body weight reduction over 68 weeks, with 60% achieving at least 20% weight loss and 23% losing 30% or more. ### What is CagriSema? CagriSema is the combination of cagrilintide (amylin analog) with semaglutide (GLP-1 receptor agonist). The two compounds produce complementary appetite suppression through different neural circuits. The REDEFINE 1 trial demonstrated 20.4% average weight loss, significantly exceeding either compound alone. ### What are Cagrilintide side effects? The most common side effects are gastrointestinal: nausea (especially during dose escalation), vomiting, diarrhea, constipation, and abdominal discomfort. Decreased appetite is an expected pharmacological effect. Serious risks include pancreatitis, severe dehydration from prolonged vomiting, and gallbladder disease with significant weight loss. ### Is Cagrilintide FDA approved? Cagrilintide is not currently FDA-approved for any indication as of early 2026 and remains under investigation. The combination product CagriSema is in late-stage clinical development. All current use outside of clinical trials is considered off-label and investigational with limited safety characterization. ### How is Cagrilintide dosed? Cagrilintide follows a gradual dose escalation: 0.25 mg weekly for weeks 1 to 4, increasing through 0.5, 1.0, and 1.7 mg steps, reaching the maintenance dose of 2.4 mg weekly by week 17. This slow titration protocol minimizes gastrointestinal side effects during treatment initiation. ## References 1. Lau DCW, Erichsen L, Francisco-Ziller N, et al.. "Once-weekly cagrilintide for weight management in people with overweight and obesity: a multicentre, randomised, double-blind, placebo-controlled and active-controlled, dose-finding phase 2 trial." *Lancet*, 2021. PMID: 34798060. https://pubmed.ncbi.nlm.nih.gov/34798060/ 2. Garvey WT, Blüher M, Osorto Contreras CK, et al.. "Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity." *New England Journal of Medicine*, 2025. PMID: 40544433. https://pubmed.ncbi.nlm.nih.gov/40544433/ 3. Kruse T, Hansen JL, Dahl K, et al.. "Development of Cagrilintide, a Long-Acting Amylin Analogue." *J Med Chem*, 2021. PMID: 34288673. https://pubmed.ncbi.nlm.nih.gov/34288673/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Cagrilintide has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/cagrilintide --- # Dulaglutide **Dulaglutide** Category: Weight Loss > Long-Acting GLP-1 Receptor Agonist for Weight Loss Dulaglutide is a long-acting GLP-1 receptor agonist engineered as a fusion protein with a human IgG4 Fc domain, enabling once-weekly subcutaneous dosing. At the maximum approved dose of 4.5 mg weekly, it produces approximately 5% body weight reduction (about 4.7 kg in the pivotal AWARD-11 trial). It is FDA-approved for glycemic control in type 2 diabetes and cardiovascular risk reduction. ## Key Facts - **Molecular weight:** ~63 kDa (approx. 63,000 g/mol) (source: https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/125469s051lbl.pdf) - **Molecular formula:** C2646H4044N704O836S18 (source: https://www.chemsrc.com/en/cas/923950-08-7_1470497.html) - **Sequence length:** 275 amino acids per chain (homodimer of 2 identical disulfide-linked chains) (source: https://www.ncbi.nlm.nih.gov/pubmed/21154170) - **Primary target:** GLP-1 receptor (source: https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/125469s051lbl.pdf) - **Mechanism class:** GLP-1 receptor agonist (long-acting; Fc-fusion protein) (source: https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/125469s051lbl.pdf) - **Half-life:** approximately 5 days (source: https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/125469s051lbl.pdf) - **Route of administration:** Subcutaneous injection, once weekly (source: https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/125469s051lbl.pdf) - **Regulatory status:** FDA-approved (Trulicity, 2014) for glycemic control in type 2 diabetes mellitus (adults and pediatric patients 10+) and reduction of major adverse cardiovascular events in adults with T2DM (source: https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/125469s051lbl.pdf) - **CAS number:** 923950-08-7 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/substance/sid/135360107/synonyms/JSON) ## Overview Dulaglutide is a long-acting glucagon-like peptide-1 (GLP-1) receptor agonist engineered as a fusion protein combining a modified GLP-1 analog linked to a human IgG4 Fc domain. This structural design extends its half-life to approximately five days, enabling once-weekly subcutaneous dosing. It mimics the action of endogenous GLP-1, an incretin hormone released from intestinal L-cells in response to food intake, by binding to and activating GLP-1 receptors throughout the body. The primary mechanism through which dulaglutide produces weight loss is multifactorial. It stimulates glucose-dependent insulin secretion from pancreatic beta cells, suppresses inappropriate glucagon secretion from alpha cells, and slows gastric emptying to reduce the rate at which nutrients enter the bloodstream after meals. Critically for weight management, GLP-1 receptor activation in hypothalamic and brainstem centers that regulate appetite leads to reduced hunger signaling and earlier satiety, resulting in reduced caloric intake over time. Clinical trials have documented meaningful weight reduction across the available dose range. At the lowest approved dose (0.75 mg weekly), average weight loss approximates 1.5 to 2.5 kg over 26 weeks. At the maximum approved dose of 4.5 mg weekly, clinical data from the pivotal AWARD-11 trial show an average body weight reduction of approximately 4.7 kg (roughly 5%) at 36 weeks, which is clinically meaningful but modest relative to higher-efficacy GLP-1 class agents such as semaglutide. The AWARD and REWIND trial programs established cardiovascular benefits as well, including reduced risk of major adverse cardiovascular events in patients with type 2 diabetes and established cardiovascular disease or high cardiovascular risk. Recent research has expanded understanding of dulaglutide's mechanisms beyond glucose and weight. A 2025 study published in Diabetes demonstrated weight-independent therapeutic effects on hepatic steatosis: dulaglutide reduced de novo lipogenesis, decreased lipid droplet stability, attenuated hepatic inflammation, and lowered oxidative stress in liver tissue, independent of body weight changes. These findings suggest a direct hepatoprotective role that may be relevant to metabolic-associated steatotic liver disease (MASLD), though this indication remains under investigation. ## Dosage Route: Subcutaneous injection, once weekly; prefilled single-dose pens ### Schedule | Period | Dose | | --- | --- | | Weeks 1-4 | 0.75 mg (initial dose; type 2 diabetes monotherapy) | | Weeks 5+ | 1.5 mg (standard maintenance dose) | | Optional escalation | 3.0 mg at 4-week intervals based on tolerability | | Maximum dose | 4.5 mg weekly (greatest weight loss effect) | ### Reconstitution - Vial size: Prefilled pen (0.75 mg, 1.5 mg, 3.0 mg, or 4.5 mg) - Water volume: 0.5 mL per dose (all strengths) - Concentration: 1.5 mg/mL, 3 mg/mL, 6 mg/mL, or 9 mg/mL depending on strength - Per unit: Single-dose prefilled pen; no reconstitution required ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 0.75 mg | 0.5 mL | Single pen injection | | 1.5 mg | 0.5 mL | Single pen injection | | 3.0 mg | 0.5 mL | Single pen injection | | 4.5 mg | 0.5 mL | Single pen injection | ### Tips - Begin at 0.75 mg once weekly for 4 weeks, then increase to 1.5 mg - Further increases to 3.0 mg and 4.5 mg may be made at 4-week intervals - Administer on the same day each week; day of week may be changed if last dose was 3+ days prior - Can be administered at any time of day, with or without food - Rotate injection sites: abdomen, thigh, or upper arm - Dulaglutide is used outside of its FDA-approved type 2 diabetes indication in some research and clinical weight management contexts ## Side Effects ### Common - Nausea (most frequent, especially during dose escalation) - Diarrhea and vomiting - Abdominal pain and dyspepsia - Decreased appetite - Fatigue - Injection site reactions: redness or bruising ### Severe / Theoretical Risks - **Pancreatitis**: Acute pancreatitis has been reported with dulaglutide. Discontinue immediately if suspected and seek urgent medical care. - **Hypoglycemia**: Risk increases significantly when combined with insulin or sulfonylureas. Monitor blood glucose carefully in combination therapy. - **Acute kidney injury**: Often secondary to severe gastrointestinal fluid losses. Monitor renal function, particularly during episodes of nausea, vomiting, or diarrhea. - **Severe gastrointestinal disease**: Ileus and gastroparesis have been reported. Use with caution in patients with pre-existing gastroparesis. - **Thyroid C-cell tumors**: Observed in rodent studies at all doses tested. Dulaglutide carries a boxed warning and is contraindicated in patients with a personal or family history of medullary thyroid carcinoma or MEN 2. ### Contraindications - Personal or family history of medullary thyroid carcinoma - Multiple endocrine neoplasia syndrome type 2 (MEN 2) - Prior serious hypersensitivity reaction to dulaglutide or any component of the formulation - Pregnancy (weight loss not recommended; GLP-1 receptor agonists should be discontinued at least 2 months before planned conception) ## FAQ ### What is Dulaglutide and how does it work? Dulaglutide is a long-acting GLP-1 receptor agonist engineered as a fusion protein with a human IgG4 Fc domain, extending its half-life to approximately five days for once-weekly dosing. It reduces appetite through brain GLP-1 receptor activation, slows gastric emptying, and improves glucose-dependent insulin secretion. ### How much weight can you lose on Dulaglutide? At the maximum approved dose of 4.5 mg weekly, clinical data from the pivotal AWARD-11 trial show approximately 4.7 kg of weight loss, roughly 5% of body weight, at 36 weeks. Lower doses produce less weight loss: 0.75 mg weekly averages 1.5 to 2.5 kg over 26 weeks. Weight loss is driven primarily by reduced caloric intake from appetite suppression rather than increased metabolism. ### What is the Dulaglutide dosage schedule? Begin at 0.75 mg once weekly for 4 weeks, then increase to 1.5 mg. Further increases to 3.0 mg and 4.5 mg may be made at 4-week intervals based on tolerability. Administer on the same day each week at any time of day, with or without food, using the prefilled single-dose pen. ### What are Dulaglutide side effects? The most common side effect is nausea during dose escalation, followed by diarrhea, vomiting, abdominal pain, decreased appetite, and fatigue. Serious risks include pancreatitis, hypoglycemia when combined with insulin or sulfonylureas, acute kidney injury from dehydration, and thyroid C-cell tumors observed in rodent studies. ### How does Dulaglutide compare to Semaglutide and Liraglutide? Semaglutide produces the greatest weight loss (approximately 15%), followed by liraglutide 3.0 mg at about 8%, while dulaglutide at 4.5 mg achieves the least at roughly 5%. Dulaglutide and semaglutide are both once-weekly, while liraglutide requires daily injections. All three share similar GI side effect profiles and carry the same boxed warning. ### Is Dulaglutide FDA approved for weight loss? Dulaglutide is FDA-approved as Trulicity for glycemic management in type 2 diabetes and cardiovascular risk reduction, not weight loss as a primary indication. Its use for weight management represents off-label application. The AWARD trial program established both metabolic and cardiovascular benefits in diabetic populations. ## References 1. Wysham C, Blevins T, Arakaki R, et al.. "Efficacy and safety of dulaglutide added onto pioglitazone and metformin versus exenatide in type 2 diabetes in a randomized controlled trial (AWARD-1)." *Diabetes Care*, 2014. PMID: 24879836. https://pubmed.ncbi.nlm.nih.gov/24879836/ 2. Gerstein HC, Colhoun HM, Dagenais GR, et al.. "Dulaglutide and cardiovascular outcomes in type 2 diabetes (REWIND): a double-blind, randomised placebo-controlled trial." *Lancet*, 2019. PMID: 31189511. https://pubmed.ncbi.nlm.nih.gov/31189511/ 3. Frias JP, Bonora E, Nevarez Ruiz L, et al.. "Efficacy and Safety of Dulaglutide 3.0 mg and 4.5 mg Versus Dulaglutide 1.5 mg in Metformin-Treated Patients With Type 2 Diabetes in a Randomized Controlled Trial (AWARD-11)." *Diabetes Care*, 2021. PMID: 33397768. https://pubmed.ncbi.nlm.nih.gov/33397768/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Dulaglutide has not been approved by the FDA for weight loss as a primary indication; its FDA approval covers glycemic management in type 2 diabetes and cardiovascular risk reduction. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/dulaglutide --- # hGH Fragment 176-191 **hGH Fragment 176-191** Category: Weight Loss > C-Terminal GH Fragment for Targeted Fat Loss hGH Fragment 176-191 is a synthetic 16-amino-acid peptide corresponding to the lipolytic region of human growth hormone. It activates fat cell lipase pathways to mobilize stored triglycerides while downregulating lipogenic enzymes, without affecting the IGF-1 axis or insulin sensitivity. ## Key Facts - **Molecular weight:** 1859.1 g/mol (PubChem CID 172966176, acetate salt form) (source: https://pubchem.ncbi.nlm.nih.gov/compound/172966176) - **Molecular formula:** C80H127N23O24S2 (PubChem CID 172966176, acetate salt) (source: https://pubchem.ncbi.nlm.nih.gov/compound/172966176) - **Sequence length:** 16 (source: https://rest.uniprot.org/uniprotkb/P01241.fasta) - **Mechanism class:** Growth hormone C-terminal lipolytic fragment (purported lipolytic agent; lipolytic claims derive largely from the modified analog AOD9604, not the bare fragment) (source: https://pubmed.ncbi.nlm.nih.gov/11713213/) - **Regulatory status:** Not FDA-approved; research-use-only / not approved for human use. Has not been studied in humans (only the modified analog AOD9604 has clinical/human data). (source: https://jofem.org/index.php/jofem/article/view/157/194) - **CAS number:** 66004-57-7 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16131230) ## Overview hGH Fragment 176-191 is a synthetic peptide corresponding to amino acids 176 through 191 at the C-terminal end of the human growth hormone (hGH) molecule. This 16-amino-acid sequence was identified in research as the region of full-length GH responsible for the hormone's lipolytic (fat-burning) activity. By isolating and stabilizing this fragment, researchers produced a peptide that retains the fat-metabolism effects of growth hormone without the growth-promoting, insulin-desensitizing, or glucose-elevating properties of the intact molecule. The mechanism of action is concentrated at the adipocyte level. hGH Fragment 176-191 binds to receptors on fat cell membranes that are coupled to adenylate cyclase, triggering an increase in intracellular cyclic AMP (cAMP). Elevated cAMP activates protein kinase A (PKA), which in turn phosphorylates and activates hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL). These lipases catalyze the hydrolysis of stored triglycerides into free fatty acids and glycerol, a process called lipolysis. Simultaneously, the fragment downregulates lipogenic enzymes including acetyl-CoA carboxylase, reducing the rate of new fat synthesis. The combined effect is a net shift toward fat mobilization and away from fat storage, particularly in visceral and abdominal depots. Because this fragment lacks the domains of full-length hGH that stimulate the IGF-1 axis and promote cell proliferation and skeletal growth, it does not produce the side effects associated with exogenous GH therapy, including glucose dysregulation, joint pain, carpal tunnel syndrome, and acromegaloid features. This selectivity has made it an attractive research subject for targeted fat reduction. Animal studies have demonstrated dose-dependent lipolytic effects and weight loss, with evidence suggesting non-linear dose-response relationships. Published studies using oral and injectable forms of the fragment in both animal and early human models demonstrated significant reductions in lipogenic activity and corresponding increases in lipolytic activity in adipose tissue. Animal studies consistently showed reductions in body weight gain, with preferential loss from visceral fat rather than lean tissue. The fragment does not appear to impair insulin sensitivity or alter blood glucose homeostasis, which is a significant advantage over full-length GH and over many other lipolytic agents. It remains an unapproved research compound in the United States and most major regulatory jurisdictions. ## Dosage Route: Subcutaneous injection; fasted state preferred for optimal lipolytic effect ### Schedule | Period | Dose | | --- | --- | | Research fat loss protocols | 200-500 mcg/day once or twice daily, fasted state | | Clinical trial reference dose | 1 mg/day once daily, morning fasted | | Higher-end research use | 500 mcg to 3 mg/day split doses, pre-workout or fasted AM/PM | ### Reconstitution - Vial size: 5 mg - Water volume: 2.5 mL bacteriostatic water - Concentration: 2 mg/mL (2,000 mcg/mL) - Per unit: Each 0.1 mL (10 units on a U-100 syringe) = 200 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 200 mcg | 0.1 mL | 10 units | | 250 mcg | 0.125 mL | 12.5 units | | 500 mcg | 0.25 mL | 25 units | | 1 mg | 0.5 mL | 50 units | ### Tips - Add bacteriostatic water slowly, directing the stream along the side of the vial rather than directly onto the powder - Swirl gently to dissolve; do not shake - Refrigerate reconstituted solution and use within 30 days; protect from light - Administer in a fasted state (before eating or 2 hours post-meal) for optimal lipolytic effect - Elevated insulin blunts fat cell responsiveness to lipolytic signals; avoid dosing after meals - Morning and pre-exercise timing is commonly reported in research protocols - Rotate injection sites to avoid lipoatrophy from repeated dosing at the same site ## Side Effects ### Common - Injection site reactions: redness, mild swelling, or irritation at the subcutaneous injection site - Localized fat loss at repeated injection sites (lipoatrophy) if same site is used repeatedly; rotate sites - Transient fatigue or lightheadedness (especially if administered in a deeply fasted state) - Mild hypoglycemia: possible in combination with fasting or caloric restriction; monitor blood glucose ### Severe / Theoretical Risks - **Hypersensitivity reactions**: Though rare, peptide injections can cause allergic reactions including rash or, in very rare cases, anaphylaxis. Discontinue and seek emergency care if systemic allergic reaction develops. - **Unknown long-term safety profile**: No multi-year human safety data exist. Potential effects on lipid trafficking, hormone signaling, or adipose tissue architecture over years of use are not established. - **Interactions with insulin or metabolic medications**: Additive effects on glucose metabolism could be clinically significant in diabetic patients or those on insulin therapy. ### Contraindications - Active malignancy (theoretical concern regarding fat mobilization supporting tumor energy metabolism, though no specific evidence exists for this fragment) - Pregnancy or breastfeeding - Known hypersensitivity to growth hormone peptides - Severe hypoglycemia history or brittle diabetes without medical supervision ## FAQ ### What is hGH Fragment 176-191 and how does it burn fat? hGH Fragment 176-191 is a 16-amino acid peptide from the lipolytic region of human growth hormone. It activates fat cell lipase pathways to mobilize stored triglycerides while downregulating lipogenic enzymes, all without affecting the IGF-1 axis, insulin sensitivity, or blood glucose homeostasis. ### How much fat loss can you expect from hGH Fragment 176-191? Preclinical studies in animal models have examined dose-response relationships, with some evidence suggesting non-linear effects where intermediate doses produce robust outcomes. However, published human clinical efficacy data for this peptide remains limited. ### What is the hGH Fragment 176-191 dosage? Research fat loss protocols use 200 to 500 mcg once or twice daily in a fasted state. The clinical trial reference dose was 1 mg daily administered in the morning while fasted. Higher-end protocols use up to 3 mg daily in split doses, taken pre-workout or during fasted morning and evening windows. ### Why must hGH Fragment 176-191 be taken while fasting? Elevated insulin blunts fat cell responsiveness to lipolytic signals. Since hGH Fragment 176-191 works by activating lipase pathways in fat cells, injecting after meals when insulin is elevated significantly reduces its effectiveness. Administering before eating or at least two hours post-meal ensures optimal fat-burning activity. ### Does hGH Fragment 176-191 cause the side effects of HGH? No. Because this fragment lacks the domains of full-length hGH that stimulate IGF-1 and promote cell proliferation, it does not produce glucose dysregulation, joint pain, carpal tunnel syndrome, or acromegaloid features associated with exogenous GH therapy. This selectivity is its primary advantage over full-length GH. ### What are hGH Fragment 176-191 side effects? Common side effects include injection site reactions, localized fat loss at repeated injection sites if not rotated, transient fatigue or lightheadedness when deeply fasted, and mild hypoglycemia with caloric restriction. Serious risks are minimal compared to full-length HGH but include rare allergic reactions and unknown long-term safety. ## References 1. Heffernan M, Summers RJ, Thorburn A, et al.. "The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out mice." *Endocrinology*, 2001. PMID: 11713213. https://pubmed.ncbi.nlm.nih.gov/11713213/ 2. Heffernan MA, Thorburn AW, Fam B, et al.. "Effects of oral administration of a synthetic fragment of human growth hormone on lipid metabolism." *Am J Physiol Endocrinol Metab*, 2000. PMID: 10950816. https://pubmed.ncbi.nlm.nih.gov/10950816/ 3. Ng FM, Sun J, Sharma L, et al.. "Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone." *Horm Res*, 2000. PMID: 11146367. https://pubmed.ncbi.nlm.nih.gov/11146367/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. hGH Fragment 176-191 has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/hgh-fragment-176-191 --- # Epithalon **Epithalon (Epitalon / AEDG Tetrapeptide)** Category: Longevity > Pineal Tetrapeptide for Longevity and Telomere Support Epithalon is a synthetic tetrapeptide (Ala-Glu-Asp-Gly) developed from the active components of the bovine pineal gland. Its primary studied mechanism is telomerase activation and telomere elongation in human somatic cells. Over 25 years of research, primarily from St. Petersburg, suggests antioxidant, neuroprotective, and antimutagenic effects alongside geroprotective action. ## Key Facts - **Molecular weight:** 390.35 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/219042/property/MolecularFormula,MolecularWeight,IUPACName/JSON) - **Molecular formula:** C14H22N4O9 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/219042/property/MolecularFormula,MolecularWeight,IUPACName/JSON) - **Sequence length:** 4 amino acids (Ala-Glu-Asp-Gly) (source: https://pubchem.ncbi.nlm.nih.gov/compound/219042) - **Primary target:** Telomerase (hTERT catalytic subunit) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC11943447/) - **Mechanism class:** Telomerase activator (geroprotective bioregulatory peptide) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC11943447/) - **Route of administration:** Subcutaneous or intramuscular injection (studies also used intranasal, sublingual, and parabulbar routes) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC11943447/) - **Regulatory status:** Not FDA-approved; research-use-only. No FDA-labeled drug product exists (DailyMed returns 0 results). (source: https://dailymed.nlm.nih.gov/dailymed/search.cfm?query=epitalon) - **CAS number:** 307297-39-8 (alternate: 64082-79-7) (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/219042/JSON?heading=CAS) ## Overview Epithalon (also rendered as Epitalon or Epithalone) is a synthetic tetrapeptide with the amino acid sequence Ala-Glu-Asp-Gly (AEDG). It was developed by the St. Petersburg Institute of Bioregulation and Gerontology in Russia, where researcher Vladimir Khavinson and colleagues synthesized it based on the active components of epithalamin, a polypeptide extract from the bovine pineal gland. The pineal gland is the body's principal source of melatonin and plays a central role in circadian regulation and aging. The most studied mechanism of Epithalon's action involves telomerase activation. Telomeres are the protective caps at the ends of chromosomes that shorten with each cell division; critically short telomeres trigger cell senescence or apoptosis, contributing to tissue aging. Research published in the Bulletin of Experimental Biology and Medicine found that adding Epithalon to cultures of telomerase-negative human fetal fibroblasts induced expression of hTERT (the catalytic subunit of telomerase), enzymatic telomerase activity, and measurable telomere elongation. Human clinical research, while limited in scale, has produced some notable results. A long-term clinical study in elderly persons found that Epithalamin reduced mortality by 1.6-1.8-fold and decreased incidence of age-related conditions including cardiovascular, endocrine, and metabolic dysfunction. A clinical trial in retinitis pigmentosa patients found that Epithalon produced a positive clinical effect in 90% of treated subjects. Additional research suggests antioxidant, neuroprotective, and antimutagenic effects, as well as modulation of neuroendocrine function including melatonin synthesis. The research base for Epithalon spans over 25 years and includes in vitro, in vivo, and in silico methods. However, the vast majority of primary studies come from a single Russian research group, and independent replication in Western academic institutions remains sparse. The peptide is not approved by any major regulatory body and is sold strictly as a research compound. ## Dosage Route: Subcutaneous or intramuscular injection ### Schedule | Period | Dose | | --- | --- | | Research standard | 10 mg/day for 10-20 consecutive days, 2-3 times per year | | Conservative | 5 mg/day for 10 days, 2 times per year | | Aggressive research | 20 mg/day for 20 days, 3 times per year | ### Reconstitution - Vial size: 10 mg - Water volume: 2 mL - Concentration: 5 mg/mL - Per unit: Each 1.0 mL = 5 mg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 5 mg | 1.0 mL | Full dose (5 mg/mL) | | 10 mg | 2.0 mL | Use two injections | | 2.5 mg | 0.5 mL | Half dose | ### Tips - Use a 29-31 gauge insulin syringe for subcutaneous injection - Inject into abdominal fat, rotating sites daily - Store reconstituted vial refrigerated and use within 28 days - Nasal spray formulations exist but have no human clinical data supporting bioavailability or efficacy - Adhere to cycle schedules rather than continuous use ## Side Effects ### Common - Injection site redness, bruising, or swelling - Fatigue during active cycle days - Mild headache - Transient changes in sleep patterns (often described as deeper sleep) ### Severe / Theoretical Risks - **Unknown long-term safety**: No long-term (multi-year) human safety studies have been published; chronic telomerase activation carries theoretical oncologic risk because cancer cells exploit telomerase to achieve replicative immortality. - **Potential tumor promotion**: Indiscriminate telomerase activation in cells with subclinical mutations could theoretically accelerate tumor progression; this risk is theoretical but biologically plausible and unresolved by current data. - **Hormonal modulation**: Effects on the pineal-pituitary axis are plausible given the pineal tissue origin of the parent compound; full endocrine impact is unstudied. ### Contraindications - Active or prior malignancy (telomerase activation is contraindicated in cancer contexts) - Pregnancy or breastfeeding - Autoimmune conditions with proliferative components - Concurrent use of immunosuppressive therapies (potential interactions unstudied) ## FAQ ### What is Epithalon and how does it work? Epithalon is a synthetic tetrapeptide (Ala-Glu-Asp-Gly) derived from the bovine pineal gland. Its primary mechanism is telomerase activation, which elongates telomeres on chromosomes. Shorter telomeres trigger cell aging and death, so Epithalon may slow cellular aging by maintaining telomere length. ### Does Epithalon really activate telomerase? Published research found that Epithalon induced hTERT expression, enzymatic telomerase activity, and measurable telomere elongation in human fetal fibroblast cultures. Clinical studies in elderly patients showed increased telomere lengths in blood cells compared to controls. However, most data comes from a single Russian research group. ### What is the standard Epithalon dosage protocol? The standard research protocol is 10 mg per day for 10 to 20 consecutive days, repeated two to three times per year. Conservative protocols use 5 mg daily for 10 days twice yearly. The peptide is injected subcutaneously into abdominal fat using an insulin syringe. ### Is Epithalon safe for long-term use? No multi-year human safety studies have been published. The primary theoretical concern is that chronic telomerase activation could promote tumor growth, since cancer cells exploit telomerase to achieve replicative immortality. Individuals with active or prior malignancy should avoid Epithalon entirely. ### What are the side effects of Epithalon? Common side effects include injection site redness, fatigue during active cycle days, mild headache, and transient changes in sleep patterns often described as deeper sleep. Serious risks are theoretical but include potential tumor promotion from indiscriminate telomerase activation in cells with existing mutations. ### How long before Epithalon shows results? Epithalon effects on telomere length are measured over months to years, not days or weeks. Reported subjective effects like improved sleep quality may appear during active dosing cycles. Research protocols repeat cycles two to three times per year for ongoing telomere maintenance. ## References 1. Khavinson VKh, Bondarev IE, Butyugov AA. "Epithalon peptide induces telomerase activity and telomere elongation in human somatic cells." *Bull Exp Biol Med*, 2003. PMID: 12937682. https://pubmed.ncbi.nlm.nih.gov/12937682/ 2. Anisimov VN, Khavinson VKh, Popovich IG, et al.. "Effect of Epitalon on biomarkers of aging, life span and spontaneous tumor incidence in female Swiss-derived SHR mice." *Biogerontology*, 2003. PMID: 14501183. https://pubmed.ncbi.nlm.nih.gov/14501183/ 3. Khavinson VKh, Morozov VG. "Peptides of pineal gland and thymus prolong human life." *Neuro Endocrinol Lett*, 2003. PMID: 14523363. https://pubmed.ncbi.nlm.nih.gov/14523363/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Epithalon has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/epithalon --- # NAD+ **NAD+ (Nicotinamide Adenine Dinucleotide)** Category: Longevity > Essential Coenzyme for Energy, DNA Repair, and Longevity NAD+ is a coenzyme essential to hundreds of metabolic reactions in every living cell. Beyond its role as an electron carrier in cellular respiration, it functions as a substrate for sirtuins (gene regulation and mitochondrial biogenesis), PARPs (DNA repair), and CD38. Cellular NAD+ levels decline approximately 50% between ages 40 and 60, correlating with mitochondrial dysfunction and accelerated aging. Injectable NAD+ produces more immediate and pronounced tissue increases than oral precursors and is used in longevity, addiction recovery, and cognitive optimization protocols. ## Key Facts - **Molecular weight:** 663.4 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/925/property/MolecularFormula,MolecularWeight/JSON) - **Molecular formula:** C21H27N7O14P2 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/925/property/MolecularFormula,MolecularWeight/JSON) - **Primary target:** NAD+-dependent enzymes: sirtuins (SIRT1-7), poly(ADP-ribose) polymerases (PARPs), and CD38; also the mitochondrial electron transport chain as a redox cofactor (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC7963035/) - **Mechanism class:** Coenzyme / redox cofactor (electron carrier) and substrate for NAD+-consuming enzymes (sirtuin deacetylases, PARPs, CD38); not a receptor agonist (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC7963035/) - **Route of administration:** Subcutaneous injection or intravenous infusion (IV clinic-supervised) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC6751327/) - **Regulatory status:** Not FDA-approved for any indication; injectable NAD+ is not a dietary supplement and is available only via pharmacy compounding (a nominated bulk drug substance under FDA review); considered research/wellness-use only with FDA adverse-event reports on record (source: https://www.fda.gov/drugs/human-drug-compounding/bulk-drug-substances-used-compounding-under-section-503a-fdc-act) - **CAS number:** 53-84-9 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/925/JSON?heading=CAS) ## Overview Nicotinamide adenine dinucleotide (NAD+) is a coenzyme found in every living cell and is essential to hundreds of metabolic reactions. While technically a coenzyme rather than a peptide in the traditional sense, NAD+ is widely categorized alongside peptide therapies in regenerative and longevity medicine due to its injectable administration protocols and overlapping clinical applications. NAD+ exists in two interconvertible forms: the oxidized form (NAD+) and the reduced form (NADH). Its primary biological role is as an electron carrier in cellular respiration, shuttling electrons from metabolic substrates to the mitochondrial electron transport chain to generate ATP. Beyond energy metabolism, NAD+ functions as a critical signaling molecule and substrate for several enzyme classes. Sirtuins (SIRT1-7), a family of NAD+-dependent deacetylases, use NAD+ to regulate gene expression, DNA repair, mitochondrial biogenesis, and metabolic homeostasis. Poly(ADP-ribose) polymerases (PARPs), which repair DNA strand breaks, are also major consumers of cellular NAD+. CD38, an enzyme involved in immune cell signaling and calcium homeostasis, is another significant NAD+ consumer that becomes increasingly active with age and chronic inflammation, further depleting available NAD+. A central finding driving clinical interest in NAD+ supplementation is the well-documented decline of cellular NAD+ levels with age. Tissue NAD+ levels fall progressively across the lifespan, and this decline is mechanistically linked to mitochondrial dysfunction, impaired DNA repair capacity, increased oxidative stress, and the accumulation of senescent cells. Animal studies in which NAD+ was restored pharmacologically showed reversal of multiple aging biomarkers, extension of lifespan in some models, and improvements in physical function, cognition, and metabolic health. Clinical research in humans is more limited but encouraging. A pharmacokinetic study showed that oral nicotinamide riboside (NR) is uniquely and bioavailable in humans and produces dose-dependent increases in blood NAD+ levels. Injectable NAD+ produces more immediate and pronounced increases in tissue NAD+ levels compared to oral precursors, which must be converted through multiple enzymatic steps. Patients in clinical settings frequently report rapid improvements in energy, mental clarity, and sleep quality within 24-48 hours of intravenous or subcutaneous NAD+ administration, consistent with acute mitochondrial activation and nervous system recalibration. ## Dosage Route: Subcutaneous injection or intravenous infusion (IV must be clinic-supervised) ### Schedule | Period | Dose | | --- | --- | | Introductory (subcutaneous) | 50 mg, once weekly for 4 weeks | | Standard maintenance (subcutaneous) | 100 mg, once weekly | | Intensive (IV infusion) | 250-500 mg, once weekly or bi-weekly | | High-dose IV (clinic-supervised) | 500-1,000 mg per infusion session | ### Reconstitution - Vial size: 500 mg - Water volume: 5 mL sterile or bacteriostatic water - Concentration: 100 mg/mL - Per unit: Each 1.0 mL = 100 mg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 50 mg | 0.5 mL | SC | | 100 mg | 1.0 mL | SC | | 200 mg | 2.0 mL | SC or IV | ### Tips - Swirl gently; do not shake. The powder dissolves readily at room temperature - Subcutaneous injections are administered into the lower abdomen or thigh using a 27-30 gauge needle - IV infusions should be administered by trained medical personnel; slow infusion rates (over 2-4 hours) significantly reduce common side effects - Store refrigerated at 2-8 degrees Celsius; use within 30 days of reconstitution - Use bacteriostatic water if the vial will be used over multiple sessions ## Side Effects ### Common - Flushing and warmth: common with IV administration, especially at faster infusion rates; slowing the infusion rate usually resolves this promptly - Nausea: reported more frequently with IV than subcutaneous routes; typically mild and transient - Fatigue: some users experience paradoxical fatigue after initial sessions, often resolving after 1-2 treatments - Headache: usually mild; related to transient vasodilation - Muscle cramping or tightness: occasionally reported with subcutaneous injections at or near the injection site - Increased heart rate: transient tachycardia reported with faster IV infusion rates; generally self-limiting ### Severe / Theoretical Risks - **Hypoglycemia risk**: NAD+ supplementation can enhance insulin sensitivity over time. Individuals on blood glucose-lowering medications should monitor glucose levels closely when initiating therapy. - **Allergic reactions**: Rare but possible, as with any injectable compound. Emergency protocols should be available when administering IV formulations. - **Drug interactions**: NAD+ metabolism intersects with niacin pathways. Individuals taking high-dose niacin should use caution and consult a physician to avoid additive effects. ### Contraindications - Active malignancy (NAD+ supports cellular proliferation; implications for cancer biology are not fully characterized) - Pregnancy and breastfeeding (insufficient safety data) - Severe liver or kidney disease - Known allergy to any component of the formulation - Current use of medications that significantly alter NAD+ metabolism, without physician oversight ## FAQ ### What is NAD+ and why does it decline with age? NAD+ is a coenzyme essential to hundreds of metabolic reactions in every cell, functioning as an electron carrier and substrate for sirtuins, PARPs, and CD38. Cellular NAD+ levels decline approximately 50% between ages 40 and 60 due to increased CD38 activity, chronic inflammation, and reduced biosynthesis. ### What are the benefits of NAD+ injections vs oral supplements? Injectable NAD+ produces more immediate and pronounced tissue increases compared to oral precursors like NR or NMN, which must be converted through multiple enzymatic steps. Patients frequently report rapid improvements in energy, mental clarity, and sleep quality within 24 to 48 hours of IV or subcutaneous administration. ### What is the standard NAD+ injection dosage? Introductory subcutaneous doses start at 50 mg once weekly for four weeks. Standard maintenance is 100 mg weekly. Intensive IV infusions range from 250 to 500 mg once weekly or bi-weekly. High-dose clinic-supervised IV sessions use 500 to 1,000 mg per infusion administered slowly over two to four hours. ### What are NAD+ IV therapy side effects? Common side effects include flushing and warmth (especially with fast IV rates), nausea, paradoxical fatigue after initial sessions, mild headache, muscle cramping, and transient increased heart rate. Slowing the IV infusion rate usually resolves most acute side effects promptly during the session. ### How often should you get NAD+ therapy? Subcutaneous maintenance protocols typically involve 100 mg weekly on an ongoing basis. IV infusion protocols vary from weekly to bi-weekly sessions. Some clinicians recommend an intensive loading phase of three to five consecutive daily IV sessions followed by weekly or monthly maintenance treatments. ### Is NAD+ safe for people with cancer? NAD+ is generally contraindicated for people with active malignancy because it supports cellular proliferation and the implications for cancer biology are not fully characterized. NAD+ fuels energy production in all cells, including potentially cancerous ones. Consult an oncologist before considering NAD+ therapy. ## References 1. Yoshino J, Baur JA, Imai SI.. "NAD+ Intermediates: The Biology and Therapeutic Potential of NMN and NR." *Cell Metabolism*, 2018. PMID: 29249689. https://pubmed.ncbi.nlm.nih.gov/29249689/ 2. Covarrubias AJ, Perrone R, Grozio A, Verdin E.. "NAD+ metabolism and its roles in cellular processes during ageing." *Nature Reviews Molecular Cell Biology*, 2021. PMID: 33353981. https://pubmed.ncbi.nlm.nih.gov/33353981/ 3. Trammell SAJ, Schmidt MS, Weidemann BJ, et al.. "Nicotinamide riboside is uniquely and orally bioavailable in mice and humans." *Nature Communications*, 2016. PMID: 27721479. https://pubmed.ncbi.nlm.nih.gov/27721479/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. NAD+ has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/nad-plus --- # Humanin **Humanin (Mitochondrial-Derived Peptide)** Category: Longevity > Endogenous Mitochondrial Peptide for Longevity Humanin is a 24-amino acid endogenous peptide encoded within the mitochondrial genome. Circulating humanin levels decline with advancing age and correlate inversely with metabolic dysfunction, cardiovascular disease, and cognitive decline. Research has linked higher humanin levels to exceptional longevity in centenarian offspring. It exerts cytoprotective effects through PI3K/Akt activation, BAX inactivation, and reduction of reactive oxygen species. ## Key Facts - **Molecular weight:** 2687.2 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/16131438/property/MolecularFormula,MolecularWeight,IUPACName/JSON) - **Molecular formula:** C119H204N34O32S2 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/16131438/property/MolecularFormula,MolecularWeight,IUPACName/JSON) - **Sequence length:** 24 amino acids (source: https://rest.uniprot.org/uniprotkb/Q8IVG9.txt) - **Primary target:** Pro-apoptotic protein BAX (sequesters/inhibits); also binds IGFBP-3 and signals via the CNTFR/WSX-1/gp130 receptor complex and formyl peptide receptors FPR2/FPR3 (source: https://rest.uniprot.org/uniprotkb/Q8IVG9.txt) - **Mechanism class:** Mitochondrial-derived peptide (cytoprotective/anti-apoptotic signaling peptide) (source: https://www.uniprot.org/uniprotkb/Q8IVG9/entry) - **Half-life:** ~30 minutes (HNG analog, IP, wild-type mice); >4 hours in rats -- species- and IGFBP-3-binding-dependent (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC3776863/) - **Route of administration:** Injection -- subcutaneous or intravenous (research use); intraperitoneal in animal models (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC3776863/) - **Regulatory status:** Not FDA approved for any indication; research-use-only / investigational, no completed human clinical trials (source: https://pubchem.ncbi.nlm.nih.gov/compound/16131438) - **CAS number:** 330936-69-1 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/16131438/synonyms/JSON) ## Overview Humanin is a 24-amino acid endogenous peptide encoded within the 16S ribosomal RNA region of the mitochondrial genome. It was first identified in 2001 as a neuroprotective factor capable of suppressing the neuronal cell death induced by proteins associated with familial Alzheimer's disease. Since that discovery, humanin has been recognized as a founding member of a broader class called mitochondrial-derived peptides (MDPs), small signaling molecules that communicate mitochondrial stress states to distant tissues. Circulating humanin levels decline with advancing age and correlate inversely with multiple markers of metabolic dysfunction, cardiovascular disease, and cognitive decline. Research from USC's Leonard Davis School of Gerontology found that offspring of centenarians have significantly higher humanin levels than age-matched controls, providing human evidence linking this peptide to exceptional longevity. Long-lived species such as the naked mole rat maintain high humanin levels across decades of life, while short-lived rodent models show steep declines within the first 16 months. Mechanistically, humanin exerts cytoprotective effects through several interconnected pathways. It activates the PI3K/Akt survival pathway in cardiomyocytes, inactivates the pro-apoptotic protein BAX, and upregulates the anti-apoptotic protein BCL-2. In neurons, it blocks amyloid-beta toxicity and prevents tau hyperphosphorylation. It also reduces reactive oxygen species (ROS) production in multiple cell types, limiting the oxidative damage that accumulates with age. Animal studies demonstrated that treating middle-aged mice with the potent humanin analog HNG (S14G-humanin) twice weekly improved metabolic healthspan parameters and reduced systemic inflammatory markers. Chronic treatment of aged female mice over 14 months with HNG prevented age-related myocardial fibrosis. Human clinical evidence remains limited, and humanin therapy is currently an investigational research tool, not an approved medical treatment. ## Dosage Route: Subcutaneous or intravenous injection ### Schedule | Period | Dose | | --- | --- | | Animal model (HNG analog) | 4 mg/kg intraperitoneally twice weekly | | Human subcutaneous (investigational) | 1-4 mg per injection, 1-3 times weekly | ### Reconstitution - Vial size: Varies by supplier - Water volume: Bacteriostatic water per vial labeling - Concentration: Per vial labeling - Per unit: Varies by reconstitution volume ### Tips - Reconstitute lyophilized humanin or HNG powder with bacteriostatic water using sterile technique - Store reconstituted peptide refrigerated at 2-8 degrees Celsius and use within 30 days - The synthetic analog HNG (S14G-humanin) is significantly more potent than native humanin due to a single amino acid substitution at position 14 - Cycle length of 4-12 weeks with off periods is used in investigational research contexts - Human dosing data are not established through clinical trials; protocols are extrapolations from animal research ### Cycling - On period: 4-12 weeks - Off period: Variable - Notes: Off periods are incorporated in investigational research use; no standardized human protocol exists ## Side Effects ### Common - Injection site reactions (redness, swelling, mild discomfort at subcutaneous injection sites) - Fatigue or mild lethargy (reported anecdotally in some research contexts) - Headache (uncommon, typically mild) - Transient nausea (more common with higher doses or IV administration) ### Severe / Theoretical Risks - **Hypoglycemia risk**: Humanin has demonstrated insulin-sensitizing effects; use caution in individuals on insulin or secretagogues. - **Unknown immunological effects**: Pharmacological doses exceeding endogenous levels may produce immunological effects that are not yet characterized. - **Potential interference with apoptotic regulation**: Theoretical oncological concern given anti-apoptotic activity in rapidly dividing tissues; not demonstrated in research. ### Contraindications - Active malignancy (theoretical concern given anti-apoptotic activity) - Known hypersensitivity to humanin or any excipient in the formulation - Pregnancy or breastfeeding (no safety data available) - Concurrent use of drugs affecting mitochondrial function (interactions unknown) - Type 1 diabetes without close glucose monitoring ## FAQ ### What is Humanin and why is it linked to longevity? Humanin is a 24-amino acid peptide encoded within the mitochondrial genome that declines with age. Research from USC found that offspring of centenarians have significantly higher humanin levels than age-matched controls. It exerts cytoprotective effects through PI3K/Akt activation and BAX inactivation. ### How does Humanin protect cells from aging? Humanin activates the PI3K/Akt survival pathway, inactivates the pro-apoptotic protein BAX, upregulates anti-apoptotic BCL-2, blocks amyloid-beta toxicity in neurons, prevents tau hyperphosphorylation, and reduces reactive oxygen species production. These combined mechanisms protect cells from age-related damage and death. ### What is HNG and how does it relate to Humanin? HNG (S14G-humanin) is a synthetic analog of humanin with a single amino acid substitution at position 14 that makes it significantly more potent than native humanin. Animal studies using HNG twice weekly improved metabolic healthspan parameters, reduced systemic inflammatory markers, and prevented age-related myocardial fibrosis. ### What is the Humanin dosage? Animal model doses use 4 mg/kg of the HNG analog intraperitoneally twice weekly. Investigational human subcutaneous doses range from 1 to 4 mg per injection, one to three times weekly, with cycle lengths of 4 to 12 weeks. Human dosing has not been established through clinical trials. ### What are Humanin side effects? Common effects include injection site reactions, mild fatigue, uncommon headache, and transient nausea at higher doses. Theoretical risks include hypoglycemia from insulin-sensitizing effects, unknown immunological effects at pharmacological doses, and potential interference with normal apoptotic regulation in rapidly dividing tissues. ### Is Humanin safe for people with cancer? Humanin is generally contraindicated for people with active malignancy due to its anti-apoptotic activity. By blocking programmed cell death pathways and activating survival signaling, it could theoretically protect cancer cells from normal elimination mechanisms. No clinical data exist to clarify this risk. ## References 1. Hashimoto Y, Niikura T, Tajima H, et al.. "Detailed characterization of neuroprotection by a rescue factor humanin against various Alzheimer's disease-relevant insults." *J Neurosci*, 2001. PMID: 11717357. https://pubmed.ncbi.nlm.nih.gov/11717357/ 2. Yen K, Wan J, Mehta HH, et al.. "The mitochondrial derived peptide humanin is a regulator of lifespan and healthspan." *Aging (Albany NY)*, 2020. PMID: 32575074. https://pubmed.ncbi.nlm.nih.gov/32575074/ 3. Karachaliou C, Livaniou E, Evangelou A. "Neuroprotective Action of Humanin and Humanin Analogues: Research Findings and Perspectives." *Biology (Basel)*, 2023. PMID: 38132360. https://pubmed.ncbi.nlm.nih.gov/38132360/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Humanin has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/humanin --- # FOXO4-DRI **FOXO4-DRI (D-Retro-Inverso Senolytic Peptide)** Category: Longevity > Senolytic Peptide for Longevity FOXO4-DRI is a synthetic senolytic peptide engineered to selectively eliminate senescent cells from aging tissues by disrupting the FOXO4-p53 interaction that keeps zombie cells alive. Built from D-amino acids in a retro-inverso topology, it resists enzymatic degradation. Animal studies demonstrated restored physical fitness, improved fur density, and improved renal function following treatment. ## Key Facts - **Molecular weight:** 5358.15 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/167312269) - **Molecular formula:** C228H388N86O64 (source: https://pubchem.ncbi.nlm.nih.gov/compound/167312269) - **Sequence length:** 46 amino acids (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/167312269/JSON) - **Primary target:** FOXO4-p53 protein-protein interaction (competitively disrupts FOXO4 binding to p53 in senescent cells) (source: https://pubmed.ncbi.nlm.nih.gov/28340339/) - **Mechanism class:** Senolytic peptide (FOXO4-p53 interaction inhibitor; induces p53-mediated apoptosis selectively in senescent cells) (source: https://pubmed.ncbi.nlm.nih.gov/28340339/) - **Route of administration:** Preclinical studies used intraperitoneal and intravenous injection in mice; subcutaneous injection in investigational human use (no clinical PK established) (source: https://pubmed.ncbi.nlm.nih.gov/28340339/) - **Regulatory status:** Not FDA approved for any indication; no registered human clinical trials; research-use-only / not approved for human use (source: https://clinicaltrials.gov/api/v2/studies?query.term=FOXO4-DRI&format=json) - **CAS number:** 2460055-10-9 (source: https://pubchem.ncbi.nlm.nih.gov/compound/167312269) ## Overview FOXO4-DRI is a synthetic senolytic peptide engineered to selectively eliminate senescent cells, commonly referred to as zombie cells, from aging tissues. Senescent cells are cells that have permanently exited the cell cycle in response to damage, oncogenic stress, or replicative exhaustion. Rather than dying through programmed cell death (apoptosis), they persist and secrete a destructive mixture of pro-inflammatory cytokines, proteases, and growth factors known as the senescence-associated secretory phenotype (SASP). Accumulation of senescent cells is a major driver of age-related tissue dysfunction, chronic inflammation, and organ decline. The peptide is designed using D-retro-inverso (DRI) topology, meaning it is built from D-amino acids arranged in a reversed sequence relative to the native FOXO4 protein. This configuration confers exceptional resistance to enzymatic degradation by proteases, giving FOXO4-DRI superior in vivo stability compared to peptides constructed from standard L-amino acids. The DRI designation is integral to the molecule's function, not merely a nomenclatural detail. The mechanism of action targets the molecular survival circuit that keeps senescent cells alive. The transcription factor FOXO4 interacts with the tumor suppressor p53 within senescent cells, sequestering p53 in the nucleus and preventing it from triggering apoptosis. FOXO4-DRI competitively disrupts this FOXO4-p53 interaction. Once unbound, p53 translocates from the nucleus to the cytoplasm, where it activates the pro-apoptotic protein BAX, initiating the execution phase of apoptosis specifically in senescent cells. In vitro studies demonstrated an 11.73-fold difference in cytotoxicity between senescent and healthy control cells, confirming that healthy cells are largely spared. Published animal studies have shown compelling results. In naturally aged and chemotherapy-induced aging mouse models, FOXO4-DRI treatment restored physical fitness, improved fur density and appearance, and improved renal function. Studies on aged male mice showed that FOXO4-DRI improved the testicular microenvironment and partially restored testosterone secretion by eliminating senescent Leydig cells. A 2025 study in Nature Communications further characterized the structural basis of the FOXO4-p53 interaction and validated the peptide's mechanism using biophysical methods. ## Dosage Route: Subcutaneous injection (investigational human use) ### Schedule | Period | Dose | | --- | --- | | Animal study protocol | 5 mg/kg intraperitoneally, every other day for 3 total administrations over 5 days | | Investigational human range | 1-5 mg subcutaneous, 2-3 times per week during active cycle | ### Reconstitution - Vial size: Varies by supplier - Water volume: Bacteriostatic water or sterile saline per vial labeling - Concentration: Per vial labeling - Per unit: Varies by reconstitution volume ### Tips - Reconstitute lyophilized FOXO4-DRI with bacteriostatic water or sterile saline - Due to the D-amino acid composition, the peptide is stable under standard refrigeration (2-8 degrees Celsius) for extended periods - Protect from light during storage - Human investigational protocols typically cycle 1-2 weeks per quarter - Human dosing has not been established through clinical trials; all protocols are extrapolated from animal research ### Cycling - On period: 1-2 weeks - Off period: Approximately 3 months (quarterly cycle) - Notes: Investigational human protocols report quarterly cycles of 1-2 weeks of active administration ## Side Effects ### Common - Injection site reactions (local redness, swelling, discomfort) - Transient fatigue following administration cycles - Mild flu-like symptoms (possibly related to clearance of senescent cells and associated SASP reduction) - Transient gastrointestinal upset ### Severe / Theoretical Risks - **Off-target apoptosis in healthy cells**: Selectivity established in vitro but human tissue response at pharmacological doses is uncertain. - **Inflammatory surge**: Simultaneous release of SASP factors as senescent cells die may produce an inflammatory surge similar to a Herxheimer-type reaction. - **Interaction with cancer treatments**: Unknown interactions with active cancer treatments; apoptosis modulation may interfere with chemotherapy mechanisms. - **Immune dysregulation**: Senescent cells serve signaling functions in wound healing and tissue homeostasis; wholesale clearance may disrupt these processes. ### Contraindications - Active cancer treatment (theoretical interaction with apoptosis-based therapeutic mechanisms) - Post-surgical recovery (senescent cells contribute to acute wound healing signaling) - Pregnancy or breastfeeding (no data; apoptosis induction is contraindicated in fetal development contexts) - Known hypersensitivity to the peptide or formulation excipients - Severe immunodeficiency (SASP clearance may alter immune signaling unpredictably) ## FAQ ### What is FOXO4-DRI and how does it fight aging? FOXO4-DRI is a synthetic senolytic peptide that selectively eliminates senescent (zombie) cells from aging tissues. It disrupts the FOXO4-p53 interaction that keeps damaged cells alive, releasing p53 to trigger apoptosis specifically in senescent cells. Built from D-amino acids, it resists enzymatic degradation for superior stability. ### How does FOXO4-DRI selectively kill senescent cells? In senescent cells, FOXO4 sequesters p53 in the nucleus, preventing apoptosis. FOXO4-DRI competitively disrupts this interaction, freeing p53 to activate the pro-apoptotic protein BAX. In vitro studies showed an 11.73-fold difference in cytotoxicity between senescent and healthy cells, confirming selective targeting. ### What results did FOXO4-DRI show in animal studies? In naturally aged and chemotherapy-induced aging mouse models, FOXO4-DRI treatment restored physical fitness, improved fur density and appearance, improved renal function, and partially restored testosterone secretion. These results demonstrate meaningful functional rejuvenation through targeted senescent cell clearance. ### What is the FOXO4-DRI dosage? Animal studies used 5 mg/kg intraperitoneally every other day for three total administrations over five days. Investigational human protocols use 1 to 5 mg subcutaneous two to three times per week during active cycles. Typical human cycling is one to two weeks per quarter with approximately three months between cycles. ### What are FOXO4-DRI side effects? Common effects include injection site reactions, transient fatigue, mild flu-like symptoms from senescent cell clearance, and gastrointestinal upset. Potential serious risks include off-target apoptosis in healthy cells, inflammatory surge from simultaneous SASP release, and immune dysregulation from removing cells that serve signaling functions. ### Is FOXO4-DRI safe for humans? Human safety data are extremely limited. FOXO4-DRI has not entered formal clinical trials and all human protocols are investigational extrapolations from animal research. The peptide's selectivity for senescent cells was established in vitro, but human tissue response at pharmacological doses remains uncertain. No FDA approval exists. ## References 1. Baar MP, Brandt RMC, Putavet DA, et al.. "Targeted Apoptosis of Senescent Cells Restores Tissue Homeostasis in Response to Chemotoxicity and Aging." *Cell*, 2017. PMID: 28340339. https://pubmed.ncbi.nlm.nih.gov/28340339/ 2. Huang Y, He Y, Makarcyzk MJ, et al.. "Senolytic Peptide FOXO4-DRI Selectively Removes Senescent Cells From in vitro Expanded Human Chondrocytes." *Front Bioeng Biotechnol*, 2021. PMID: 33996787. https://pubmed.ncbi.nlm.nih.gov/33996787/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. FOXO4-DRI has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/fox04-dri --- # SS-31 **SS-31 (Elamipretide)** Category: Cellular Health > Mitochondria-Targeting Peptide for Cellular Health SS-31, known generically as elamipretide, is a synthetic tetrapeptide that selectively accumulates in the inner mitochondrial membrane by binding to cardiolipin. It stabilizes mitochondrial electron transport chain function, reduces reactive oxygen species production, and improves ATP synthesis -- making it a subject of clinical investigation in heart failure, Barth syndrome, and age-related mitochondrial dysfunction. ## Key Facts - **Molecular weight:** 639.8 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/11764719) - **Molecular formula:** C32H49N9O5 (source: https://pubchem.ncbi.nlm.nih.gov/compound/11764719) - **Sequence length:** 4 (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC11816484/) - **Primary target:** Cardiolipin (inner mitochondrial membrane phospholipid) (source: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=146bf34c-76f2-48db-ac07-fb29cce2cd75) - **Mechanism class:** Mitochondria-targeting peptide / cardiolipin binder (mitochondrial function stabilizer) (source: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=146bf34c-76f2-48db-ac07-fb29cce2cd75) - **Route of administration:** Subcutaneous injection (approved product, 40 mg once daily); intravenous infusion in clinical trials (source: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=146bf34c-76f2-48db-ac07-fb29cce2cd75) - **Regulatory status:** FDA accelerated approval Sept 19, 2025 as FORZINITY (elamipretide HCl) to improve muscle strength in Barth syndrome patients >=30 kg; all other uses (anti-aging, HFpEF, general mitochondrial support) investigational/not approved (source: https://www.fda.gov/news-events/press-announcements/fda-grants-accelerated-approval-first-treatment-barth-syndrome) - **CAS number:** 736992-21-5 (source: https://pubchem.ncbi.nlm.nih.gov/compound/11764719) ## Overview SS-31, known generically as elamipretide, is a synthetic tetrapeptide with the sequence D-Arg-dimethylTyr-Lys-Phe-NH2. It belongs to the Szeto-Schiller (SS) family of mitochondria-targeting peptides developed by Hazel Szeto and Peter Schiller. The compound was designed with a specific architectural purpose: to selectively accumulate in the inner mitochondrial membrane by binding to cardiolipin, a unique phospholipid found almost exclusively in that membrane. No other cellular membrane contains cardiolipin in significant quantities, making it an exquisitely specific molecular address for targeted drug delivery to mitochondria without requiring a conventional targeting signal sequence. The selectivity of SS-31 for the inner mitochondrial membrane is achieved through an alternating sequence of basic amino acid residues (D-Arg, Lys) and aromatic residues (dimethylTyr, Phe). The basic residues drive membrane association through electrostatic interactions, while the aromatic residues provide additional binding affinity through pi-electron interactions with the lipid bilayer. Importantly, despite bearing a net positive charge, SS-31 maintains excellent cell permeability, which research suggests is due to charge shielding by the electron-rich aromatic ring systems. This combination of membrane permeability and mitochondrial selectivity is unusual among pharmacological agents. Once bound to cardiolipin at the inner mitochondrial membrane, SS-31 stabilizes the cardiolipin-cytochrome c interaction. Cytochrome c is a key electron carrier in the mitochondrial electron transport chain (ETC); when cardiolipin is oxidized or peroxidized (as occurs during oxidative stress and aging), cytochrome c shifts from its electron carrier role to a peroxidase activity that generates damaging reactive oxygen species (ROS). SS-31 binding prevents this peroxidase shift, protecting the ETC from self-inflicted oxidative damage. The downstream effects include normalized electron transport chain efficiency, reduced mitochondrial ROS production, improved ATP synthesis, reduced mitochondrial membrane potential dysregulation, and protection against mitochondria-initiated apoptosis. Research published in PNAS identified that SS-31's interacting proteins cluster specifically around ATP synthase and the 2-oxoglutarate metabolic pathway. Preclinical studies using SS-31 have produced compelling results across multiple disease models. Eight weeks of SS-31 treatment at 3 mg/kg/day in aged mice substantially reversed cardiac diastolic dysfunction, normalized proton leak, and reduced mitochondrial ROS production in heart muscle cells. In skeletal muscle, prolonged SS-31 treatment reversed age-related energetic deficits, improved resting and dynamic muscle function, and restored redox homeostasis. Kidney disease models (including ischemia-reperfusion injury) showed significant protection. SS-31 (as elamipretide) has entered human clinical trials under the pharmaceutical company Stealth BioTherapeutics, including trials in Barth syndrome (a rare mitochondrial cardiomyopathy) and heart failure with preserved ejection fraction (HFpEF), reflecting its therapeutic potential in mitochondrial dysfunction. ## Dosage Route: Subcutaneous injection or intravenous infusion, once daily ### Schedule | Period | Dose | | --- | --- | | Research low dose | 5-10 mg subcutaneous once daily | | Research standard dose | 10-20 mg subcutaneous once daily | | Clinical trial range | Up to 40 mg/day subcutaneous or IV per protocol | | Animal model equivalent | 3 mg/kg/day subcutaneous once daily | ### Reconstitution - Vial size: 10 mg - Water volume: 1 mL (or 2 mL for lower doses) - Concentration: 10 mg/mL (or 5 mg/mL for easier low-dose measurement) - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 1 mg at 10 mg/mL ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 5 mg | 0.50 mL | 50 units | | 10 mg | 1.00 mL | 100 units | | 20 mg | 2.00 mL | Split into two injection sites | ### Tips - For volumes above 1 mL subcutaneously, split the dose between two injection sites (e.g., both sides of the lower abdomen) - Use a 25-27 gauge needle for larger volumes - IV administration should be performed by trained medical personnel using diluted infusion solutions - Refrigerate at 2-8 degrees Celsius and protect from light - Use within 4 weeks of reconstitution - Swirl gently until fully dissolved -- the solution should be clear and colorless ## Side Effects ### Common - Injection site reactions (transient redness, warmth, mild pain) - Mild, brief facial or body flushing shortly after injection - Mild nausea, more likely with higher doses - Mild fatigue in initial days of a new dosing cycle ### Severe / Theoretical Risks - **Injection site reactions (severe)**: In some Phase 2 trial participants, more pronounced local tissue reactions occurred at injection sites with prolonged daily use. Appropriate site rotation and injection technique minimize this risk. - **Cardiovascular effects**: As a compound that directly modulates mitochondrial function in cardiac cells, monitoring is warranted in individuals with significant heart disease, though the compound's primary studied application is improving cardiac mitochondrial function. ### Contraindications - Known hypersensitivity to SS-31 or any formulation component - Pregnancy and breastfeeding (insufficient safety data) - Active mitochondrial disease states that require specialist oversight before adding any mitochondria-modulating compound - Children and adolescents (insufficient safety data in this population) ## FAQ ### What is SS-31 and how does it target mitochondria? SS-31 (elamipretide) is a synthetic tetrapeptide that selectively accumulates in the inner mitochondrial membrane by binding to cardiolipin, a phospholipid unique to that membrane. It stabilizes electron transport chain function, reduces reactive oxygen species production, and improves ATP synthesis in aging or damaged cells. ### What conditions is SS-31 being studied for? SS-31 has entered human clinical trials for Barth syndrome (a rare mitochondrial cardiomyopathy) and heart failure with preserved ejection fraction. Preclinical studies show benefits in age-related cardiac dysfunction, skeletal muscle energetic deficits, kidney ischemia-reperfusion injury, and general mitochondrial dysfunction. ### What is the SS-31 dosage for anti-aging? Research low doses range from 5 to 10 mg subcutaneously once daily. Standard research doses are 10 to 20 mg daily. Clinical trial protocols have used up to 40 mg per day. For volumes above 1 mL subcutaneously, splitting the dose between two injection sites is recommended. ### What are SS-31 side effects? Common side effects include transient injection site redness, mild flushing, nausea at higher doses, and mild fatigue in initial days. More pronounced injection site reactions occurred in some Phase 2 trial participants with prolonged daily use. Appropriate site rotation minimizes local tissue reactions. ### How does SS-31 reverse aging at the cellular level? SS-31 prevents cytochrome c from shifting to a damaging peroxidase activity that occurs during aging and oxidative stress. By stabilizing the cardiolipin-cytochrome c interaction, it normalizes electron transport chain efficiency, reduces self-inflicted mitochondrial oxidative damage, and improves cellular energy production. ### Is SS-31 FDA approved? Yes, for one specific rare disease. On September 19, 2025, the FDA granted accelerated approval to FORZINITY (elamipretide HCl), made by Stealth BioTherapeutics, to improve muscle strength in adult and pediatric patients with genetically confirmed Barth syndrome weighing at least 30 kg -- the first approved therapy for Barth syndrome and the first approved mitochondria-targeted drug. This approval is limited to Barth syndrome and its continuation depends on confirmatory trials. All other uses discussed here -- anti-aging, heart failure with preserved ejection fraction (HFpEF), and general mitochondrial support -- are NOT FDA approved and remain off-label or investigational. Outside the approved Barth syndrome indication, SS-31 is used only as a research compound and is not intended for self-administration. ## References 1. Zhao K, Zhao GM, Wu D, et al.. "Cell-permeable peptide antioxidants targeted to inner mitochondrial membrane inhibit mitochondrial swelling, oxidative cell death, and reperfusion injury." *J Biol Chem*, 2004. PMID: 15178689. https://pubmed.ncbi.nlm.nih.gov/15178689/ 2. Birk AV, Liu S, Soong Y, et al.. "The mitochondrial-targeted compound SS-31 re-energizes ischemic mitochondria by interacting with cardiolipin." *J Am Soc Nephrol*, 2013. PMID: 23813215. https://pubmed.ncbi.nlm.nih.gov/23813215/ 3. Szeto HH. "First-in-class cardiolipin-protective compound as a therapeutic agent to restore mitochondrial bioenergetics." *Br J Pharmacol*, 2014. PMID: 24117165. https://pubmed.ncbi.nlm.nih.gov/24117165/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. SS-31 (elamipretide) received FDA accelerated approval on September 19, 2025 as FORZINITY (elamipretide HCl) solely to improve muscle strength in patients with Barth syndrome weighing at least 30 kg; it has NOT been approved by the FDA for anti-aging, heart failure, general mitochondrial support, or any other use, all of which remain off-label or investigational. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/ss-31 --- # Selank **Selank (TKPRPGP)** Category: Cognitive > Anxiolytic and Nootropic Peptide with Benzodiazepine-Comparable Anxiety Relief Selank is a synthetic heptapeptide (TKPRPGP) developed as a stabilized analog of the immunomodulatory tetrapeptide tuftsin. It modulates GABA-A receptor sensitivity to produce anxiolytic effects comparable to low-dose benzodiazepines without sedation, tolerance, or physical dependence. It also upregulates BDNF in the hippocampus and modulates serotonin, dopamine, and immune signaling. Registered in Russia for generalized anxiety disorder under the brand name Selanc. ## Key Facts - **Molecular weight:** 751.9 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/11765600) - **Molecular formula:** C33H57N11O9 (source: https://pubchem.ncbi.nlm.nih.gov/compound/11765600) - **Sequence length:** 7 (source: https://pubchem.ncbi.nlm.nih.gov/compound/11765600) - **Primary target:** GABA-A receptor (positive modulation of sensitivity); also inhibits enkephalin-degrading enzymes (enkephalinases) (source: https://pubmed.ncbi.nlm.nih.gov/11550013/) - **Mechanism class:** Anxiolytic/nootropic heptapeptide; synthetic tuftsin analog (GABAergic modulator with enkephalinase inhibition) (source: https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2016.00031/full) - **Route of administration:** Intranasal (nasal mucosa); also intravenous/subcutaneous injection (source: https://en.wikipedia.org/wiki/Selank) - **Regulatory status:** Not FDA approved; research-use-only in the US. Registered/approved in Russia for generalized anxiety disorder and neurasthenia (brand name Selank/Selanc) (source: https://en.wikipedia.org/wiki/Selank) - **CAS number:** 129954-34-3 (source: https://pubchem.ncbi.nlm.nih.gov/compound/11765600) ## Overview Selank is a synthetic heptapeptide with the amino acid sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP). It was developed by the Institute of Molecular Genetics of the Russian Academy of Sciences as an analogue of tuftsin, a naturally occurring tetrapeptide (Thr-Lys-Pro-Arg) produced by enzymatic cleavage of the IgG immunoglobulin heavy chain. By appending the stabilizing tripeptide Pro-Gly-Pro to the native tuftsin sequence, researchers created a compound with substantially greater metabolic stability and prolonged biological activity. Selank has been studied and registered in Russia as a pharmaceutical treatment for generalized anxiety disorder (GAD) and neurasthenia under the brand name Selanc. The mechanisms by which Selank produces its anxiolytic and nootropic effects involve multiple interconnected neurotransmitter systems. Primary among these is modulation of the GABAergic system: Selank upregulates GABA-A receptor sensitivity and influences the expression of genes involved in GABA synthesis, transport, and receptor subunit composition. The resulting anxiolytic effect is comparable in magnitude to low-dose benzodiazepines. Critically, this GABAergic activity does not produce the sedation, muscle relaxation, tolerance, physical dependence, or withdrawal phenomena associated with conventional benzodiazepine anxiolytics. Published head-to-head clinical trials comparing Selank to the benzodiazepine medazepam found equivalent anxiety reduction alongside additional antiasthenic effects (relief of fatigue and weakness) and mild psychostimulation with Selank, effects absent with the benzodiazepine. Beyond GABA, Selank rapidly upregulates brain-derived neurotrophic factor (BDNF) expression in the hippocampus. BDNF is a key promoter of synaptic plasticity, neurogenesis, and long-term potentiation, making it a central target for cognitive enhancement research. Animal studies demonstrate that Selank-induced BDNF elevation occurs within hours of administration. Selank also modulates serotonin and dopamine neurotransmission, contributing to its reported effects on mood, motivation, and stress resilience. Gene expression studies have shown that Selank affects transcripts related to both GABAergic neurotransmission and immune signaling, reflecting the dual heritage of its parent compound tuftsin. The evidence base for Selank is predominantly from Russian and CIS research institutions, creating gaps in the international peer-reviewed literature and limiting independent validation. However, the available controlled clinical data, combined with a well-characterized multi-target mechanism and a consistently favorable safety profile across both animal and human studies, has generated substantial interest from the research community, clinicians practicing integrative psychiatry, and individuals exploring nootropic and anxiolytic compounds. Long-term safety data beyond the durations studied in published trials (typically a few weeks) remain unavailable. ## Dosage Route: Intranasal spray (preferred for CNS entry) or subcutaneous injection ### Schedule | Period | Dose | | --- | --- | | Conservative starting dose | 250 mcg intranasal or SC, once daily | | Standard anxiolytic dose | 500 mcg intranasal or SC, once daily | | Higher cognitive/mood dose | 750-1,000 mcg intranasal or SC, once daily | | Cycle duration | 10-14 days on, 7-14 days off | ### Reconstitution - Vial size: 10 mg - Water volume: 2 mL bacteriostatic water - Concentration: 5 mg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 500 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 250 mcg | 0.05 mL | 5 units on insulin syringe | | 500 mcg | 0.10 mL | 10 units | | 1,000 mcg | 0.20 mL | 20 units | ### Tips - For intranasal administration, tilt the head slightly forward and spray into one or both nostrils while gently sniffing - Allow 5-10 minutes after intranasal administration for mucosal absorption before assessing initial effects - Rotating nostrils with each administration reduces local irritation - For nasal atomizer use: load reconstituted 5 mg/mL solution; each 0.1 mL actuation delivers approximately 500 mcg - Refrigerate reconstituted solution at 2-8 degrees Celsius; stable for approximately 4 weeks ### Cycling - On period: 10-14 days - Off period: 7-14 days - Notes: Cycling protocols are used empirically to preserve receptor sensitivity; long-term continuous use has not been systematically studied. ## Side Effects ### Common - Mild sedation or relaxation: more pronounced at higher doses or in individuals with high baseline anxiety; generally considered a desired rather than adverse effect - Nasal irritation or congestion: local mucosal irritation with intranasal administration; usually resolves within minutes and diminishes with continued use - Mild fatigue: some users report fatigue in the first few administrations of a new cycle; typically resolves after the initial 2-3 days - Mild euphoria or mood elevation: dose-dependent; generally mild at standard research doses ### Severe / Theoretical Risks - **Additive CNS depression**: Combining Selank with alcohol, benzodiazepines, opioids, or other CNS depressants may produce additive sedation beyond what either substance produces alone. - **Immune modulation**: Tuftsin and its analogues have immunomodulatory properties. The clinical significance of Selank's immunological activity in individuals with autoimmune conditions has not been systematically studied. ### Contraindications - Pregnancy and breastfeeding (insufficient safety data) - Concurrent use of CNS depressants without medical supervision - Known hypersensitivity to tuftsin or related compounds - Individuals under 18 years of age - Epilepsy or seizure disorders (insufficient data to establish safety) ## FAQ ### What is Selank and what does it do? Selank is a synthetic heptapeptide derived from the naturally occurring tetrapeptide tuftsin. Developed at the Institute of Molecular Genetics in Russia, it functions as an anxiolytic and nootropic compound. Researchers study its effects on anxiety, cognitive function, and immune modulation through GABAergic and BDNF pathways. ### How does Selank compare to benzodiazepines for anxiety? Clinical trials comparing Selank to the benzodiazepine medazepam found equivalent anxiety reduction. Critically, Selank does not produce sedation, muscle relaxation, tolerance, physical dependence, or withdrawal phenomena associated with benzodiazepines. It additionally provides antiasthenic effects and mild psychostimulation. ### What is the recommended Selank dosage? The standard anxiolytic dose is 500 mcg intranasal or subcutaneous once daily. Conservative starting dose is 250 mcg daily, while higher cognitive and mood doses reach 750 to 1,000 mcg daily. Typical cycling is 10 to 14 days on followed by 7 to 14 days off to preserve receptor sensitivity. ### Can Selank be used as a nasal spray? Yes. Intranasal administration is the preferred route for Selank because it provides direct CNS access via olfactory pathways. Reconstituted solution at 5 mg/mL is loaded into a nasal atomizer, with each 0.1 mL actuation delivering approximately 500 mcg. Effects are typically noticed within 5 to 10 minutes. ### What are Selank side effects? Common effects include mild sedation or relaxation, nasal irritation with intranasal use, mild fatigue during the first few days, and mild euphoria at standard doses. Selank should not be combined with alcohol, benzodiazepines, or opioids due to risk of additive CNS depression. ### Is Selank FDA approved? Selank is not FDA approved. It is registered in Russia for generalized anxiety disorder under the brand name Selanc. The evidence base is predominantly from Russian research institutions, and independent replication in Western academic institutions remains limited. Long-term safety data are unavailable. ## References 1. Zozulia AA, Neznamov GG, Siuniakov TS, et al.. "Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia." *Zh Nevrol Psikhiatr Im S S Korsakova*, 2008. PMID: 18454096. https://pubmed.ncbi.nlm.nih.gov/18454096/ 2. Volkova A, Sharova E, Nevzorova T, et al.. "Selank Administration Affects the Expression of Some Genes Involved in GABAergic Neurotransmission." *Front Pharmacol*, 2016. PMID: 26924987. https://pubmed.ncbi.nlm.nih.gov/26924987/ 3. Kolik LG, Nadorova AV, Seredenin SB. "Selank, Peptide Analogue of Tuftsin, Protects Against Ethanol-Induced Memory Impairment by Regulating of BDNF Content in the Hippocampus and Prefrontal Cortex in Rats." *Bull Exp Biol Med*, 2019. PMID: 31625062. https://pubmed.ncbi.nlm.nih.gov/31625062/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Selank has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/selank --- # Semax **Semax (MEHFPGP)** Category: Cognitive > ACTH-Derived Neuroprotective Peptide for Cognitive Enhancement Semax is a synthetic heptapeptide (MEHFPGP) derived from the ACTH(4-10) sequence with stabilizing Pro-Gly-Pro additions. It retains the neurotrophic properties of ACTH without stimulating cortisol release. Semax upregulates BDNF and TrkB in the hippocampus, modulates dopaminergic, serotonergic, and cholinergic systems, and suppresses neuroinflammatory gene expression. It has been registered in Russia and CIS countries for decades for stroke recovery, traumatic brain injury, and cognitive decline. ## Key Facts - **Molecular weight:** 813.9 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/9811102/property/MolecularFormula,MolecularWeight/JSON) - **Molecular formula:** C37H51N9O10S (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/9811102/property/MolecularFormula,MolecularWeight/JSON) - **Sequence length:** 7 (source: https://pubchem.ncbi.nlm.nih.gov/compound/9811102) - **Primary target:** BDNF/TrkB signaling in the hippocampus (upregulates BDNF and its TrkB receptor); modulates dopaminergic, serotonergic and cholinergic systems (source: https://pubmed.ncbi.nlm.nih.gov/16996037/) - **Mechanism class:** ACTH(4-10)/melanocortin-derived neuroprotective and nootropic heptapeptide (neurotrophic factor inducer); does not stimulate cortisol release (source: https://pubmed.ncbi.nlm.nih.gov/16996037/) - **Route of administration:** Intranasal (primary); also subcutaneous injection (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC12755871/) - **Regulatory status:** Not approved by FDA or EMA; research-use-only in the US. Registered as a pharmaceutical in Russia (1994) and CIS countries for cerebrovascular/cognitive indications and on Russia's list of vital essential drugs. (source: https://en.wikipedia.org/wiki/Semax) - **CAS number:** 80714-61-0 (source: https://pubchem.ncbi.nlm.nih.gov/compound/9811102) ## Overview Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP). It is a structural analogue and fragment of adrenocorticotropic hormone (ACTH), specifically derived from the ACTH(4-10) sequence with stabilizing Pro-Gly-Pro additions that extend its bioactivity and resistance to enzymatic degradation. Crucially, while Semax retains the neurotrophic properties of the ACTH fragment, it lacks the hormonal activity of full-length ACTH and does not stimulate cortisol release from the adrenal glands. This separation of neurotrophic from hormonal effects makes Semax pharmacologically unique. It has been registered as a pharmaceutical in Russia and CIS countries for decades, where it is clinically prescribed for stroke recovery, traumatic brain injury, optic nerve disease, and cognitive decline. Semax operates through several distinct neurobiological mechanisms that collectively explain its cognitive-enhancing and neuroprotective profile. Most prominently, Semax significantly upregulates brain-derived neurotrophic factor (BDNF) and its receptor TrkB in the hippocampus. A single administration of Semax at 50 mcg/kg produced a 1.4-fold increase in BDNF protein and a 3-fold increase in BDNF mRNA expression in published rodent studies. BDNF is the primary driver of synaptic plasticity and long-term potentiation, making its upregulation central to improved memory formation and learning. Semax also modulates serotonin, dopamine, and acetylcholine neurotransmitter systems, suppresses neuroinflammatory gene expression, and activates expression of genes related to neurotransmission. In the context of ischemic brain injury, Semax has demonstrated particularly robust effects. Genome-wide transcriptional analysis following middle cerebral artery occlusion (pMCAO) in rats revealed that Semax significantly regulates expression of immune response genes, enhancing antigen presentation signaling and intensifying interferon signaling pathways while affecting cytokine, stress response, and ribosomal protein-encoding genes. In a photothrombosis model, six daily administrations of Semax at 250 mcg/kg reduced infarction size and improved performance on cognitive tasks. Semax also has the notable property of interacting with copper ions (Cu2+), potentially interfering with the formation of beta-amyloid-copper complexes implicated in Alzheimer's disease pathology, though this mechanism remains a subject of ongoing investigation. Clinical use of Semax in Russia has been documented over more than two decades, with applications in stroke rehabilitation, optic nerve atrophy, peptic ulcer disease, and cognitive decline in aging. A pilot study in 24 healthy subjects found that intranasal 1% Semax (total dose 1.2 mg) increased resting fMRI signal in the default mode network compared to placebo, suggesting measurable central nervous system effects at doses relevant to cognitive enhancement use. The compound is not approved by the FDA or EMA, and the published evidence base, while mechanistically compelling, lacks the large-scale randomized controlled trials that would be required for regulatory approval in Western countries. ## Dosage Route: Intranasal spray (primary) or subcutaneous injection ### Schedule | Period | Dose | | --- | --- | | Cognitive support (0.1% solution) | 200-600 mcg intranasal, once daily, 5-14 days on / 14 days off | | Neuroprotection/recovery (1% solution) | 600-1,200 mcg intranasal, once to twice daily, 5-10 days | | Injectable (subcutaneous) | 250-500 mcg SC, once daily, 5-14 days | | Research doses (healthy subjects) | 250-1,000 mcg/kg intranasal per protocol | ### Reconstitution - Vial size: 10 mg - Water volume: 2 mL bacteriostatic water - Concentration: 5 mg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 500 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 250 mcg | 0.05 mL | 5 units on insulin syringe | | 500 mcg | 0.10 mL | 10 units | | 1,000 mcg | 0.20 mL | 20 units | ### Tips - Swirl gently until fully dissolved; the solution should be clear; discard if cloudy or particulate - For intranasal use, tilt the head slightly forward; administer drops or sprays into each nostril while gently sniffing to maximize mucosal absorption - Most users report onset of cognitive effects (improved focus and clarity) within 20-40 minutes of intranasal administration - Rotating nostrils between administrations reduces local irritation - Refrigerate at 2-8 degrees Celsius; stable for approximately 4 weeks after reconstitution - Morning administration is recommended to minimize sleep disturbances ### Cycling - On period: 5-14 days - Off period: 14 days - Notes: Cycling protocols reflect standard clinical practice in Russian use; longer off periods are used to prevent neuroadaptation and maintain response. ## Side Effects ### Common - Mild stimulation or anxiety: particularly at higher doses or in users sensitive to nootropic compounds; usually transient and dose-dependent - Nasal irritation: local discomfort, dryness, or transient congestion with intranasal use; rotating nostrils between administrations reduces local irritation - Sleep disturbances: insomnia or vivid dreams occasionally reported, especially when dosing is taken later in the day; morning administration is recommended - Headache: mild, usually resolving within hours; more common at the start of a cycle - Mild euphoria: reported by some users, consistent with dopaminergic and serotonergic activity; generally brief ### Severe / Theoretical Risks - **Excessive neurological stimulation**: High doses could theoretically produce anxiety, agitation, or in extreme cases seizure activity, particularly in individuals with pre-existing seizure disorders. - **Interactions with psychoactive medications**: Semax modulates monoaminergic neurotransmission; caution is warranted when combining with SSRIs, MAOIs, or other neuroactive compounds. ### Contraindications - Pregnancy and breastfeeding (insufficient safety data) - Epilepsy or seizure disorders - Known hypersensitivity to ACTH or related peptides - Concurrent use of MAOIs or serotonergic medications without medical supervision - Children and adolescents (insufficient safety data) ## FAQ ### What is Semax and what does it do? Semax is a synthetic heptapeptide derived from the ACTH(4-10) sequence that retains neurotrophic properties without stimulating cortisol release. It upregulates BDNF and TrkB in the hippocampus, modulates dopamine, serotonin, and acetylcholine systems, and suppresses neuroinflammatory gene expression for cognitive enhancement. ### How fast does Semax work for cognitive enhancement? Most users report onset of cognitive effects including improved focus and clarity within 20 to 40 minutes of intranasal administration. A single administration produced a 1.4-fold increase in BDNF protein and 3-fold increase in BDNF mRNA in rodent studies, supporting rapid neurotrophin-mediated effects. ### What is the best Semax dosage for focus? For cognitive support, the standard protocol is 200 to 600 mcg intranasal once daily using a 0.1% solution, cycled 5 to 14 days on with 14 days off. For neuroprotection, higher doses of 600 to 1,200 mcg daily using a 1% solution are used for 5 to 10 day cycles. ### How does Semax compare to Selank? Semax is primarily a cognitive enhancer and neuroprotectant derived from ACTH, while Selank is primarily an anxiolytic derived from tuftsin. Semax tends toward stimulation and focus, while Selank tends toward calm and anxiety relief. Some research protocols combine both for complementary nootropic and anxiolytic effects. ### What are Semax side effects? Common side effects include mild stimulation or anxiety at higher doses, nasal irritation with intranasal use, sleep disturbances if dosed late in the day, mild headache at cycle start, and brief euphoria. Morning administration is recommended to minimize sleep disruption from its stimulating properties. ### Is Semax safe with antidepressants? Caution is warranted when combining Semax with SSRIs, MAOIs, or other neuroactive compounds because Semax modulates monoaminergic neurotransmission. The potential for serotonin syndrome or other interactions has not been systematically studied. Medical supervision is essential for anyone on psychiatric medications. ## References 1. Gusev EI, Skvortsova VI, Chukanova EI. "Effectiveness of semax in acute period of hemispheric ischemic stroke (a clinical and electrophysiological study)." *Zh Nevrol Psikhiatr Im S S Korsakova*, 1997. PMID: 11517472. https://pubmed.ncbi.nlm.nih.gov/11517472/ 2. Dolotov OV, Karpenko EA, Inozemtseva LS, et al.. "Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus." *Brain Res*, 2006. PMID: 16996037. https://pubmed.ncbi.nlm.nih.gov/16996037/ 3. Eremin KO, Kudrin VS, Grivennikov IA, et al.. "Semax, an ACTH(4-10) analogue with nootropic properties, activates dopaminergic and serotoninergic brain systems in rodents." *Neurochem Res*, 2005. PMID: 16362768. https://pubmed.ncbi.nlm.nih.gov/16362768/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Semax has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/semax --- # Cerebrolysin **Cerebrolysin (Porcine Brain-Derived Neuropeptide Preparation)** Category: Cognitive > Neurotrophic Peptide Preparation for Cognitive Enhancement Cerebrolysin is a neuropeptide preparation derived from porcine brain tissue that mimics endogenous neurotrophic factors including BDNF, NGF, and GDNF. Its low-molecular-weight peptide fragments cross the blood-brain barrier, and clinical evidence supports its use in stroke recovery, traumatic brain injury, and Alzheimer's disease in countries where it holds regulatory approval. ## Key Facts - **Primary target:** Neurotrophic signaling pathways; mimics endogenous neurotrophic factors (BDNF/NGF/GDNF-like activity). Specific molecular target not clearly defined. (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC3019019/) - **Route of administration:** Intravenous (IV) infusion (primary) or intramuscular (IM) injection (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC3019019/) - **Regulatory status:** Not FDA-approved in the United States (research-use-only in US). Approved in several European and Asian countries (e.g., Austria, Germany, Russia, China, South Korea) for stroke/post-apoplectic complications, traumatic brain injury, and dementia. Marketing Authorisation Holder: EVER Neuro Pharma GmbH (Austria). (source: https://en.wikipedia.org/wiki/Cerebrolysin) - **CAS number:** 12656-61-0 (source: https://www.chemicalbook.com/ChemicalProductProperty_EN_CB01326626.htm) ## Overview Cerebrolysin is a neuropeptide preparation derived from porcine brain tissue through a controlled enzymatic hydrolysis process. The resulting compound is a mixture of low-molecular-weight peptide fragments and free amino acids, the most therapeutically significant of which can cross the blood-brain barrier. This capacity for central nervous system penetration distinguishes Cerebrolysin from many other neurological compounds and is central to its proposed mechanism of action. The peptide mixture is believed to mimic the activity of endogenous neurotrophic factors, including brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and glial cell line-derived neurotrophic factor (GDNF). These proteins regulate neuronal survival, synaptic plasticity, and the growth and maintenance of neurons throughout the brain. Because the peptide fragments in Cerebrolysin are small enough to cross the blood-brain barrier where full-sized growth factors cannot, researchers have investigated whether Cerebrolysin can effectively deliver neurotrophic signaling to the central nervous system. Preclinical and clinical research has examined Cerebrolysin in the context of stroke recovery, traumatic brain injury (TBI), Alzheimer's disease, and general cognitive aging. A meta-analysis pooling six randomized, double-blind, placebo-controlled trials in mild-to-moderate Alzheimer's disease found Cerebrolysin was significantly more effective than placebo for cognitive function at four weeks, with effect sizes comparable to approved cholinesterase inhibitors. Research published in 2025 further explored its role in modulating secondary injury mechanisms following TBI, with investigators noting its potential to support neuronal survival and functional recovery. Despite these findings, Cerebrolysin remains non-approved in the United States. A 2013 Cochrane review rated the overall evidence quality as very low, citing small sample sizes, short follow-up periods, high risk of bias, and predominantly manufacturer-funded studies. It is currently approved in a number of European and Asian countries for neurological indications. Researchers and clinicians working with Cerebrolysin in the United States treat it strictly as a research compound outside of any approved therapeutic context. ## Dosage Route: Intravenous (IV) infusion (primary) or intramuscular (IM) injection ### Schedule | Period | Dose | | --- | --- | | Cognitive support (low) | 5 mL (1076 mg) daily for 10 days | | Neurological recovery (moderate) | 10-20 mL daily for 20-28 days | | Clinical trial dose (Alzheimer's) | 30 mL daily IV infusion for 4 weeks | | Maintenance cycle | 5-10 mL daily for 5-10 days, 1-3x per year | ### Reconstitution - Vial size: 5 mL or 10 mL ampoule (supplied as solution for injection -- no reconstitution required) - Water volume: Dilute in normal saline for IV administration - Concentration: 215.2 mg/mL (1076 mg per 5 mL ampoule) - Per unit: Dilute in 100-250 mL normal saline for IV infusion over 20-60 minutes ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 5 mL (1076 mg) | 5 mL IM or diluted IV | Low cognitive support dose | | 10 mL (2152 mg) | Dilute in normal saline for IV | Moderate neurological dose | | 30 mL (6456 mg) | Dilute in normal saline for IV | Clinical trial dose (Alzheimer's) | ### Tips - Cerebrolysin should not be self-administered without medical supervision - IV preparation and administration requires sterile technique and clinical oversight - Administer IV infusion slowly over 20-60 minutes to minimize side effects - Cycles of 10-20 daily injections followed by a rest period are the most common clinical approach - For cognitive support in non-pathological settings, use 5-10 mL in cycles of 10 days, repeated 1-3x per year - Higher doses (30 mL/day) do not consistently outperform moderate doses and may carry higher side effect burden ## Side Effects ### Common - Dizziness or lightheadedness following IV infusion - Fatigue or somnolence, particularly after higher doses - Mild headache - Injection site reactions with IM administration (pain, redness, swelling) - Nausea, especially with faster infusion rates - Transient elevation in body temperature ### Severe / Theoretical Risks - **Allergic or anaphylactic reactions**: Cerebrolysin is derived from animal tissue and carries a risk of hypersensitivity reactions. Reactions may range from mild urticaria to anaphylaxis. Emergency treatment should be immediately available during administration. - **Seizures**: Rare reports of seizure activity exist, particularly in individuals with pre-existing seizure disorders. - **Severe hypotension**: Rapid IV infusion has been associated with significant drops in blood pressure. ### Contraindications - Known allergy to pork or porcine-derived products - Epilepsy or active seizure disorders (use with extreme caution) - Renal failure (excretion may be impaired) - Pregnancy and breastfeeding (safety not established) - Active psychosis or acute psychiatric disturbance - Concurrent use with MAO inhibitors or antidepressants (additive CNS effects possible) ## FAQ ### What is Cerebrolysin and how does it work? Cerebrolysin is a neuropeptide preparation derived from porcine brain tissue through controlled enzymatic hydrolysis. Its low-molecular-weight peptide fragments cross the blood-brain barrier and mimic endogenous neurotrophic factors including BDNF, NGF, and GDNF, supporting neuronal survival and synaptic plasticity. ### Is Cerebrolysin effective for Alzheimer's disease? A meta-analysis of six randomized, double-blind, placebo-controlled trials found Cerebrolysin significantly more effective than placebo for cognitive function at four weeks, with effect sizes comparable to approved cholinesterase inhibitors. However, a Cochrane review rated overall evidence quality as very low due to small samples and bias. ### How is Cerebrolysin administered? Cerebrolysin is given by IV infusion (primary route) or intramuscular injection. It comes as a pre-made solution requiring no reconstitution. Cognitive support doses are 5 mL daily for 10 days. Neurological recovery uses 10 to 20 mL daily for 20 to 28 days. IV infusion should be administered slowly over 20 to 60 minutes. ### What are Cerebrolysin side effects? Common side effects include dizziness, fatigue, mild headache, injection site reactions, nausea, and transient temperature elevation. Serious risks include allergic or anaphylactic reactions (it is derived from animal tissue), rare seizure activity in predisposed individuals, and severe hypotension with rapid IV infusion. ### Is Cerebrolysin approved in the United States? No. Cerebrolysin is not approved by the FDA and remains a research compound in the United States. It is approved in several European and Asian countries for neurological indications including stroke recovery and cognitive decline. US researchers and clinicians use it strictly outside any approved therapeutic context. ### Can people allergic to pork use Cerebrolysin? No. Cerebrolysin is derived from porcine brain tissue and is contraindicated for anyone with a known allergy to pork or porcine-derived products. The animal tissue origin also carries inherent risk of hypersensitivity reactions, and emergency treatment should be immediately available during administration. ## References 1. Muresanu DF, Heiss WD, Hoemberg V, et al.. "Cerebrolysin and Recovery After Stroke (CARS): A Randomized, Placebo-Controlled, Double-Blind, Multicenter Trial." *Stroke*, 2016. PMID: 26564102. https://pubmed.ncbi.nlm.nih.gov/26564102/ 2. Bornstein NM, Guekht A, Vester J, et al.. "Safety and efficacy of Cerebrolysin in early post-stroke recovery: a meta-analysis of nine randomized clinical trials." *Neurol Sci*, 2018. PMID: 29248999. https://pubmed.ncbi.nlm.nih.gov/29248999/ 3. Gauthier S, Proano JV, Jia J, et al.. "Cerebrolysin in mild-to-moderate Alzheimer's disease: a meta-analysis of randomized controlled clinical trials." *Dement Geriatr Cogn Disord*, 2015. PMID: 25832905. https://pubmed.ncbi.nlm.nih.gov/25832905/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Cerebrolysin has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/cerebrolysin --- # P-21 **P-21 (P021)** Category: Cognitive > Synthetic Tetrapeptide for Cognitive Health P-21 is a synthetic tetrapeptide derived from the biologically active region of human ciliary neurotrophic factor (CNTF). Engineered with an adamantane modification for blood-brain barrier penetration, it promotes hippocampal neurogenesis and upregulates BDNF, with preclinical results showing disease-modifying effects in Alzheimer's disease models. ## Key Facts - **Molecular weight:** 578.7 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/56589645/property/MolecularFormula,MolecularWeight/JSON) - **Molecular formula:** C27H42N6O8 (source: https://pubchem.ncbi.nlm.nih.gov/compound/56589645) - **Sequence length:** 4 (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC9599095/) - **Primary target:** Leukemia inhibitory factor (LIF) signaling / BDNF-TrkB pathway (with downstream GSK3-beta inhibition) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC9599095/) - **Mechanism class:** CNTF-derived neurotrophic peptide mimetic (neurogenesis-promoting / BDNF-upregulating) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC9599095/) - **Half-life:** >3 hours (plasma) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC9599095/) - **Route of administration:** Oral (preclinical); intraperitoneal/subcutaneous and intranasal also studied (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC9599095/) - **Regulatory status:** Not FDA approved; preclinical / early clinical development for Alzheimer's disease (Phanes Biotech); research-use-only (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC9599095/) - **CAS number:** 1246751-68-7 (source: http://glixxlabs.com/chemical-products/bioactive-screen-leads-p6/GLXC-21260) ## Overview P-21 (also designated P021) is a synthetic tetrapeptide (four amino acids: Ac-DGGLAG-NH2) derived from the biologically active region of human ciliary neurotrophic factor (CNTF). CNTF is a naturally occurring cytokine that supports neuronal survival and differentiation, but native CNTF is too large to cross the blood-brain barrier efficiently and produces systemic side effects at therapeutic doses. P-21 was engineered to retain the neurotrophic activity of CNTF's active domain while incorporating an adamantylated glycine residue at the C-terminal end. This adamantane modification serves two critical purposes: it increases the molecule's lipophilicity to improve blood-brain barrier penetration, and it protects against degradation by exopeptidases, extending the peptide's functional half-life in biological tissues. The central mechanism of P-21 involves two complementary actions on neurotrophin signaling. First, P-21 inhibits leukemia inhibitory factor (LIF) signaling, which normally acts as a brake on adult neurogenesis. By suppressing LIF's inhibitory effect, P-21 removes a significant barrier to new neuron formation in the hippocampus, a region critical for learning, memory consolidation, and spatial navigation. Second, P-21 upregulates the expression of brain-derived neurotrophic factor (BDNF), activating the downstream BDNF/TrkB/PI3-K/AKT/GSK3-beta signaling cascade. BDNF is often described as a master regulator of neuroplasticity, promoting synaptic strengthening, dendritic branching, and neuronal survival throughout the adult brain. Animal research has produced particularly compelling results in Alzheimer's disease models. In the triple-transgenic mouse model of Alzheimer's disease (3xTg-AD), P-21 treatment initiated at 9-10 months of age and continued for 6-12 months produced multiple disease-modifying effects: rescued deficits in hippocampal neurogenesis, restored synaptic density to near-normal levels, normalized BDNF expression and glutamate receptor levels, and reversed cognitive impairments across multiple memory tasks. Crucially, P-21 also inhibited the formation of amyloid-beta plaques and tau hyperphosphorylation, two of the hallmark pathological features of Alzheimer's disease, addressing disease biology rather than merely symptomatic expression. P-21 is under active clinical development by Phanes Biotech (PA, USA) as a potential disease-modifying therapy for Alzheimer's disease and other neurodegenerative conditions. As of early 2026, no human clinical trial results have been published. The peptide is classified as a research compound and is not approved for any human therapeutic indication. Interest in P-21 has grown alongside broader interest in neurogenesis-promoting strategies as an alternative to amyloid clearance approaches that have shown variable results in late-stage clinical trials. ## Dosage Route: Intranasal (preferred) or subcutaneous injection ### Schedule | Period | Dose | | --- | --- | | Animal research (chronic) | 60 nmol/g feed for 6-12 months | | Investigational human range | 1-5 mg per administration, daily or every other day | ### Reconstitution - Vial size: Variable - Water volume: Per supplier instructions - Concentration: Concentrated for intranasal or standard for subcutaneous - Per unit: Use nasal atomizer for intranasal delivery ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 1 mg | 0.5 mL | 50 units (from 2 mg/mL solution) | | 5 mg | 2.5 mL | 250 units (from 2 mg/mL solution) | ### Tips - Reconstitute with bacteriostatic water or sterile saline - The adamantane modification confers additional stability - Store reconstituted peptide at 2-8 degrees Celsius - Use within 30 days of reconstitution - Intranasal administration may use a lower-volume concentrated solution delivered with a nasal atomizer device - Human dosing has not been established through clinical trials; all protocols are investigational ### Cycling - On period: 2-4 weeks - Off period: Variable; off periods observed in animal models - Notes: Cycle length based on investigational human protocols; no clinical data available ## Side Effects ### Common - Injection site reactions (redness, swelling, mild discomfort with subcutaneous administration) - Nasal irritation or mild burning sensation with intranasal administration - Transient headache - Mild fatigue or drowsiness, particularly at the start of treatment - Appetite changes (CNTF analogs have shown anorectic effects at higher doses in some research contexts) ### Severe / Theoretical Risks - **Excessive neurogenesis**: Long-term pharmacological upregulation of adult neurogenesis may disrupt established memory circuits, as new neuron integration is a competitive process. - **Appetite suppression**: CNTF pathway activation has produced clinically significant appetite suppression and weight loss at higher doses in prior clinical programs. - **Unknown oncogenic risk**: Chronic LIF pathway inhibition or BDNF overexpression in tissues beyond the brain may carry unknown oncogenic risk not yet characterized in humans. - **Epileptogenic potential**: BDNF can increase neuronal excitability. At very high doses there may be a risk of lowering seizure threshold. ### Contraindications - Active seizure disorder or epilepsy (BDNF potentiation may lower seizure threshold) - Active malignancy affecting the CNS (neurogenesis stimulation in a tumor-bearing brain is contraindicated) - Pregnancy or breastfeeding (neurotrophic factor modulation is contraindicated during fetal neurodevelopment) - Known hypersensitivity to P-21, adamantane-based compounds, or any component of the formulation - Concurrent use of drugs affecting BDNF/TrkB signaling (potential additive or antagonistic interactions not characterized) ## FAQ ### What is P-21 peptide and what does it do? P-21 (P021) is a synthetic tetrapeptide derived from human ciliary neurotrophic factor engineered with an adamantane modification for blood-brain barrier penetration. It promotes hippocampal neurogenesis by inhibiting LIF signaling and upregulates BDNF, showing disease-modifying effects in Alzheimer's disease animal models. ### Can P-21 help with Alzheimer's disease? In triple-transgenic Alzheimer's mouse models, P-21 rescued neurogenesis deficits, restored synaptic density, normalized BDNF expression, reversed cognitive impairments, and inhibited both amyloid-beta plaque formation and tau hyperphosphorylation. These are disease-modifying effects, not merely symptomatic improvements. Human trials are pending. ### How is P-21 administered? P-21 can be given intranasally (preferred for direct CNS access via nasal atomizer) or by subcutaneous injection. Investigational human doses range from 1 to 5 mg per administration, daily or every other day. The adamantane modification improves blood-brain barrier penetration and extends the peptide's functional half-life. ### What are P-21 side effects? Potential side effects include injection site reactions, nasal irritation with intranasal use, transient headache, mild fatigue, and appetite changes from CNTF pathway activation. Theoretical risks include excessive neurogenesis disrupting established memory circuits, appetite suppression at higher doses, and lowered seizure threshold from BDNF potentiation. ### Is P-21 FDA approved? P-21 has not been approved by the FDA for any medical condition. It is under active clinical development by Phanes Biotech as a potential disease-modifying therapy for Alzheimer's disease. As of early 2026, no human clinical trial results have been published and it remains a research compound. ### Who should not use P-21? P-21 is contraindicated for people with active seizure disorders (BDNF may lower seizure threshold), CNS malignancies (neurogenesis stimulation in tumor-bearing brain is dangerous), pregnancy (neurotrophic factor modulation risks fetal neurodevelopment), and those on drugs affecting BDNF/TrkB signaling. ## References 1. Li B, Wanka L, Bhatt RR, et al.. "Neurotrophic peptides incorporating adamantane improve learning and memory, promote neurogenesis and synaptic plasticity in mice." *FEBS Lett*, 2010. PMID: 20600002. https://pubmed.ncbi.nlm.nih.gov/20600002/ 2. Kazim SF, Blanchard J, Dai CL, et al.. "Disease modifying effect of chronic oral treatment with a neurotrophic peptidergic compound in a triple transgenic mouse model of Alzheimer's disease." *Neurobiol Dis*, 2014. PMID: 25046994. https://pubmed.ncbi.nlm.nih.gov/25046994/ 3. Bolognin S, Bhatt RR, Bhatt DK, et al.. "An experimental rat model of sporadic Alzheimer's disease and rescue of cognitive impairment with a neurotrophic peptide." *Acta Neuropathol*, 2012. PMID: 22083255. https://pubmed.ncbi.nlm.nih.gov/22083255/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. P-21 has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/p-21 --- # PE-22-28 **PE-22-28 (Optimized Spadin Analog)** Category: Cognitive > TREK-1 Inhibitor for Cognitive Health PE-22-28 is a synthetic heptapeptide developed as an optimized analog of spadin, a naturally occurring antidepressant-like molecule derived from the TREK-1 potassium channel propeptide. It achieves superior TREK-1 channel binding affinity (IC50 0.12 nM vs. 40-60 nM for spadin), extended action duration up to 23 hours, and promotes adult hippocampal neurogenesis within days of treatment. ## Key Facts - **Molecular weight:** 773.9 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/165437303) - **Molecular formula:** C35H55N11O9 (source: https://pubchem.ncbi.nlm.nih.gov/compound/165437303) - **Sequence length:** 7 amino acids (source: https://pubchem.ncbi.nlm.nih.gov/compound/165437303) - **Primary target:** TREK-1 potassium channel (TWIK-related K+ channel 1; IC50 0.12 nM) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC5601071/) - **Mechanism class:** TREK-1 channel inhibitor (spadin analog) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC5601071/) - **Regulatory status:** Not FDA approved; no registered human clinical trials; preclinical research-use only, not approved for human use (source: https://clinicaltrials.gov/search?term=PE-22-28) - **CAS number:** 1801959-12-5 (source: https://pubchem.ncbi.nlm.nih.gov/compound/165437303) ## Overview PE-22-28 is a synthetic heptapeptide (seven amino acids) developed as an optimized analog of spadin, a naturally occurring peptide derived from the propeptide of the TREK-1 potassium channel. Spadin was identified in the early 2010s as an endogenous antidepressant-like molecule, but its short duration of action (approximately 7 hours) and relatively low receptor affinity limited its therapeutic potential. PE-22-28 was engineered to address these limitations, achieving superior TREK-1 channel binding affinity, extended action duration (up to 23 hours), and improved in vivo stability. The primary target of PE-22-28 is the TREK-1 channel (TWIK-related potassium channel 1), a two-pore-domain potassium channel expressed abundantly in neurons of the hippocampus, cortex, and other brain regions relevant to mood and cognition. TREK-1 channels regulate neuronal excitability by controlling potassium ion flow across the cell membrane. When TREK-1 is overactive, it hyperpolarizes neurons and dampens neurotransmitter release, contributing to a state associated with depressive behavior. PE-22-28 binds to and inhibits TREK-1, reversing this hyperpolarization and restoring more normal patterns of neuronal excitability and neurotransmitter signaling. Preclinical research has generated compelling behavioral data. Mice with TREK-1 gene knockout are resistant to depressive-like states in standard models including the forced swimming test and tail suspension test. PE-22-28 and related spadin analogs replicating TREK-1 inhibition produced significant reductions in immobility time in the forced swimming test, a validated behavioral marker of antidepressant activity. Research published in a PMC peer-reviewed study confirmed that PE-22-28 displayed a better TREK-1 specificity and affinity (IC50 of 0.12 nM) compared to the parent molecule spadin (IC50 40-60 nM). Beyond mood regulation, PE-22-28 has shown neurogenic effects. It appears to stimulate adult hippocampal neurogenesis within a few days of treatment, promoting the formation of new neurons in a brain region critical for memory encoding, pattern separation, and emotional regulation. Multiple behavioral paradigms have shown improvements in memory formation, learning ability, and recall in rodents treated with TREK-1 inhibitors, suggesting relevance to conditions beyond depression including age-related cognitive decline. ## Dosage Route: Subcutaneous injection ### Schedule | Period | Dose | | --- | --- | | Preclinical rodent protocol | 3.0 mcg/kg subcutaneous for 4 days | | Investigational human range | 0.5-2 mg subcutaneous per administration, daily or every other day for 2-4 weeks | ### Reconstitution - Vial size: Varies by supplier - Water volume: Bacteriostatic water per vial labeling - Concentration: Per vial labeling - Per unit: Varies by reconstitution volume ### Tips - Reconstitute lyophilized PE-22-28 with bacteriostatic water to the desired concentration - Store reconstituted peptide at 2-8 degrees Celsius and use within 30 days of reconstitution - Duration of action is up to 23 hours per dose, supporting once-daily administration - Human clinical dosing has not been established; all protocols are from preclinical research or investigational reports ## Side Effects ### Common - Injection site reactions (redness, swelling, discomfort at the subcutaneous injection site) - Possible transient drowsiness or sedation (consistent with neuronal membrane stabilization) - Headache - Mild gastrointestinal discomfort ### Severe / Theoretical Risks - **Cardiovascular effects from TREK-1 inhibition**: TREK-1 channels are expressed in cardiac tissue; inhibition could theoretically affect cardiac rhythm at high doses. - **Excessive neuronal excitability**: CNS effects at suprapharmacological doses could result if TREK-1 is inhibited beyond the optimal therapeutic range. - **Drug interactions with potassium channel modulators**: Interaction with other potassium channel-modulating drugs may produce additive or antagonistic effects. - **Unknown long-term neurological consequences**: The long-term consequences of sustained adult hippocampal neurogenesis stimulation have not been characterized. ### Contraindications - Cardiac arrhythmia or known channelopathy (TREK-1 channel activity in cardiac tissue; safety unknown) - Concurrent use of antiarrhythmic drugs affecting potassium channels - Bipolar disorder (stimulation of neurogenesis and neuronal excitability may destabilize mood in bipolar individuals) - Pregnancy or breastfeeding (no data; CNS-active agents are generally avoided) - Known hypersensitivity to PE-22-28 or any component of the formulation ## FAQ ### What is PE-22-28 and how does it work? PE-22-28 is a synthetic heptapeptide that inhibits the TREK-1 potassium channel in neurons. When TREK-1 is overactive, it dampens neurotransmitter release contributing to depressive states. PE-22-28 reverses this hyperpolarization, restoring normal neuronal excitability with an IC50 of 0.12 nM and action lasting up to 23 hours. ### Does PE-22-28 promote new brain cell growth? Yes. PE-22-28 stimulates adult hippocampal neurogenesis within days of treatment, promoting formation of new neurons in a brain region critical for memory encoding and emotional regulation. Multiple behavioral studies show improvements in memory formation, learning ability, and recall in rodents treated with TREK-1 inhibitors. ### How does PE-22-28 compare to traditional antidepressants? PE-22-28 works through an entirely different mechanism than SSRIs or SNRIs, targeting potassium channels rather than monoamine reuptake. Preclinical data show rapid onset of antidepressant-like effects within days rather than weeks. However, no human clinical trials have been conducted to validate these findings in people. ### What is the PE-22-28 dosage? Preclinical rodent protocols use 3.0 mcg/kg subcutaneously for 4 days. Investigational human ranges are 0.5 to 2 mg subcutaneous per administration, daily or every other day for 2 to 4 weeks. The 23-hour duration of action supports once-daily dosing. Human clinical dosing has not been formally established. ### What are PE-22-28 side effects? Potential side effects include injection site reactions, drowsiness, headache, and mild gastrointestinal discomfort. Theoretical risks include cardiovascular effects from TREK-1 inhibition in cardiac tissue, excessive neuronal excitability at high doses, and unknown long-term consequences of sustained hippocampal neurogenesis stimulation. ### Is PE-22-28 safe for people with bipolar disorder? PE-22-28 is contraindicated for individuals with bipolar disorder. Stimulation of neurogenesis and neuronal excitability through TREK-1 inhibition may destabilize mood cycling in bipolar individuals. The compound is also contraindicated for people with cardiac arrhythmias or those taking antiarrhythmic drugs affecting potassium channels. ## References 1. Djillani A, Pietri M, Mazella J, et al.. "Shortened Spadin Analogs Display Better TREK-1 Inhibition, In Vivo Stability and Antidepressant Activity." *Front Pharmacol*, 2017. PMID: 28955242. https://pubmed.ncbi.nlm.nih.gov/28955242/ 2. Mazella J, Petrault O, Lucas G, et al.. "Spadin, a sortilin-derived peptide, targeting rodent TREK-1 channels: a new concept in the antidepressant drug design." *PLoS Biol*, 2010. PMID: 20405001. https://pubmed.ncbi.nlm.nih.gov/20405001/ 3. Djillani A, Mazella J, Heurteaux C, et al.. "Fighting against depression with TREK-1 blockers: Past and future. A focus on spadin." *Pharmacol Ther*, 2019. PMID: 30291907. https://pubmed.ncbi.nlm.nih.gov/30291907/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. PE-22-28 has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/pe-22-28 --- # DSIP **DSIP (Delta Sleep-Inducing Peptide)** Category: Sleep > Neuropeptide for Sleep Induction and Stress Modulation DSIP is a nine-amino acid neuropeptide first isolated in 1974 that produces spindle and delta EEG activity characteristic of deep, restorative sleep. Found endogenously in the hypothalamus, limbic system, and pituitary, it also appears to modulate melatonin release, suppress stress arousal pathways, and regulate circadian rhythms. Clinical evidence is limited but promising. ## Key Facts - **Molecular weight:** 848.8 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/68816) - **Molecular formula:** C35H48N10O15 (source: https://pubchem.ncbi.nlm.nih.gov/compound/68816) - **Sequence length:** 9 amino acids (Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu / WAGGDASGE) (source: https://pubchem.ncbi.nlm.nih.gov/compound/68816) - **Mechanism class:** Endogenous sleep-modulating neuropeptide (nonapeptide); no defined receptor-agonist pharmacological class (source: https://pubmed.ncbi.nlm.nih.gov/16539679/) - **Half-life:** ~15 minutes (in vitro, due to aminopeptidase-like enzyme degradation) (source: https://pubmed.ncbi.nlm.nih.gov/6548966/) - **Route of administration:** Subcutaneous injection (intravenous used in early human clinical studies) (source: https://pubmed.ncbi.nlm.nih.gov/3622582/) - **CAS number:** 62568-57-4 (source: https://pubchem.ncbi.nlm.nih.gov/compound/68816) ## Overview Delta Sleep-Inducing Peptide (DSIP) is a neuropeptide consisting of nine amino acids in the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE). It was first isolated in 1974 by Swiss researchers who identified it in the cerebral venous blood of rabbits during slow-wave sleep induction. When infused into the mesodiencephalic ventricle of recipient animals, the peptide reliably produced spindle and delta EEG activity characteristic of deep, restorative sleep. DSIP is found endogenously in the hypothalamus, limbic system, pituitary, and peripheral organs, suggesting broad physiological roles beyond sleep alone. The precise mechanism by which DSIP promotes sleep remains incompletely understood. In vitro, the peptide has a very short half-life of roughly 15 minutes due to degradation by aminopeptidase-like enzymes. Proposed mechanisms include enhancement of slow-wave delta sleep, modulation of melatonin release, and dampening of corticotropin-releasing factor (CRF)-mediated stress arousal pathways. Some research also implicates DSIP in regulating circadian rhythm entrainment and reducing basal corticosterone levels. Human clinical data on DSIP is limited and the results are mixed. A double-blind study in chronic insomnia patients found that DSIP substantially improved night sleep with the first and repeated doses, with sleep efficiency reaching normal control levels and alertness/daytime performance increasing significantly. A separate study found some evidence of benefit on sleep architecture in the night following infusion. Researchers have also observed potential stress-buffering effects, and animal studies suggest neuroprotective and antioxidant properties. The research base for DSIP is substantially thinner than for better-studied sleep peptides, and no well-powered phase III human trials have been completed. The peptide's instability in plasma complicates both its study and its therapeutic application. Users should understand that its clinical utility for insomnia remains unproven by rigorous standards. ## Dosage Route: Subcutaneous injection, administered 30-60 minutes before sleep ### Schedule | Period | Dose | | --- | --- | | Conservative starting dose | 100 mcg subcutaneous, evening | | Standard research dose | 100-300 mcg subcutaneous, 30-60 min before sleep | ### Reconstitution - Vial size: 5 mg - Water volume: 2.5 mL - Concentration: 2000 mcg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 200 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 100 mcg | 0.05 mL | 5 units | | 200 mcg | 0.10 mL | 10 units | | 300 mcg | 0.15 mL | 15 units | ### Tips - Inject into abdominal subcutaneous fat - Administer 30-60 minutes before intended sleep time - Use an insulin syringe for accurate measurement at small volumes - Store reconstituted solution refrigerated and use within 28 days - Start at the lowest dose (100 mcg) to assess individual response ## Side Effects ### Common - Drowsiness or sedation (expected effect) - Mild headache - Brief nausea following injection - Dizziness when standing quickly after injection - Injection site irritation ### Severe / Theoretical Risks - **Unknown long-term toxicity**: No long-term human safety data exists; chronic use parameters are entirely unstudied. - **Hormonal disruption**: DSIP modulates corticosterone and pituitary hormone axes; prolonged use could theoretically perturb endocrine function. - **Rapid plasma degradation and unpredictable dosing**: Short half-life means bioavailability from subcutaneous injection is highly variable and difficult to predict. ### Contraindications - Pregnancy or breastfeeding - Active CNS disorders or epilepsy (potential EEG-modulating effects) - Concurrent use of sedative medications or benzodiazepines (additive CNS depression risk) - Known hypersensitivity to neuropeptides ## FAQ ### What is DSIP and what does it do? DSIP (Delta Sleep-Inducing Peptide) is a nine-amino acid neuropeptide first isolated in 1974 that promotes deep, restorative sleep. Found naturally in the hypothalamus and pituitary, it produces spindle and delta EEG activity, modulates melatonin release, and suppresses stress arousal pathways. ### How does DSIP improve sleep? DSIP enhances slow-wave delta sleep, the deepest and most restorative sleep phase. It also modulates melatonin release, dampens corticotropin-releasing factor stress pathways, and helps regulate circadian rhythm entrainment. These combined mechanisms promote deeper, more structured sleep architecture. ### What is the recommended DSIP dosage for sleep? The standard research dose is 100 to 300 mcg injected subcutaneously 30 to 60 minutes before intended sleep time. Starting at the lowest dose of 100 mcg is recommended to assess individual response. The peptide has a very short plasma half-life of roughly 15 minutes. ### What are the side effects of DSIP? Common side effects include expected drowsiness, mild headache, brief nausea after injection, dizziness when standing quickly, and injection site irritation. No long-term human safety data exists, and the peptide's hormonal effects on cortisol and pituitary axes are not fully characterized. ### Is DSIP safe to use with other sleep medications? DSIP should not be combined with sedative medications or benzodiazepines due to the risk of additive central nervous system depression. The peptide's EEG-modulating effects also make it potentially risky for individuals with epilepsy or other CNS disorders. Medical supervision is essential. ### How does DSIP compare to melatonin for sleep? DSIP works through different mechanisms than melatonin, targeting delta wave sleep induction and stress pathway suppression rather than circadian signaling alone. However, DSIP has substantially less clinical evidence supporting its use, a very short half-life, and no regulatory approval in any country. ## References 1. Graf MV, Kastin AJ. "Delta-sleep-inducing peptide (DSIP): a review." *Neurosci Biobehav Rev*, 1984. PMID: 6145137. https://pubmed.ncbi.nlm.nih.gov/6145137/ 2. Graf MV, Kastin AJ. "Delta-sleep-inducing peptide (DSIP): an update." *Peptides*, 1986. PMID: 3550726. https://pubmed.ncbi.nlm.nih.gov/3550726/ 3. Schneider-Helmert D, Schoenenberger GA. "Effects of delta-sleep-inducing peptide on 24-hour sleep-wake behaviour in severe chronic insomnia." *Eur Neurol*, 1987. PMID: 3622582. https://pubmed.ncbi.nlm.nih.gov/3622582/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. DSIP has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/dsip --- # Thymosin Alpha-1 **Thymosin Alpha-1 (Thymalfasin)** Category: Immune > Thymic Peptide for Immune System Support Thymosin Alpha-1 (Ta1) is a 28-amino acid peptide naturally produced by the thymus gland that modulates both innate and adaptive immunity. Approved in over 35 countries as Zadaxin for chronic hepatitis B, chronic hepatitis C, and immune enhancement, it activates T cells, NK cells, and dendritic cells through Toll-like receptor signaling. ## Key Facts - **Molecular weight:** 3108.3 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/16130571) - **Molecular formula:** C129H215N33O55 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16130571) - **Sequence length:** 28 amino acids (source: https://pubchem.ncbi.nlm.nih.gov/compound/16130571) - **Primary target:** Toll-like receptors (TLR-2, TLR-4, TLR-9) on immune cells (source: https://www.rxlist.com/zadaxin-drug.htm) - **Mechanism class:** Immunomodulator / thymic peptide (T-cell modulator, TLR agonist) (source: https://www.rxlist.com/zadaxin-drug.htm) - **Half-life:** approximately 2 hours (serum half-life, subcutaneous) (source: https://www.rxlist.com/zadaxin-drug.htm) - **Route of administration:** Subcutaneous injection (should not be given intravenously) (source: https://www.rxlist.com/zadaxin-drug.htm) - **Regulatory status:** Not FDA-approved; approved as Zadaxin (thymalfasin) in 35+ countries for chronic hepatitis B/C and immune enhancement; used in the US only as research/off-label compounded formulation (source: https://pubchem.ncbi.nlm.nih.gov/compound/16130571) - **CAS number:** 62304-98-7 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16130571) ## Overview Thymosin Alpha-1 (Ta1), also known as thymalfasin, is a 28-amino acid peptide that occurs naturally in the thymus gland. It was first isolated in 1977 by Allan Goldstein at George Washington University from thymosin fraction 5, a preparation of calf thymus extracts that had shown immunomodulatory properties. The thymus is the primary organ responsible for the maturation and education of T lymphocytes, and Thymosin Alpha-1 is one of the key thymic peptides mediating this process. Concentrations of Thymosin Alpha-1 in blood decline with age as the thymus undergoes progressive involution, a parallel that has fueled interest in its potential role in age-related immune decline. The immune-modulating mechanisms of Thymosin Alpha-1 are broad and operate across both innate and adaptive immunity. At the molecular level, Ta1 binds to Toll-like receptors TLR-2, TLR-4, and TLR-9 on immune cells, activating downstream NF-kappaB and IRF3 signaling pathways. This signaling promotes the proliferation and functional activation of key immune cell types including T helper cells, cytotoxic T cells, natural killer (NK) cells, dendritic cells, and macrophages. The net effect is a coordinated enhancement of cell-mediated immune responses, which are particularly critical for defense against viral infections, intracellular bacterial pathogens, and cancer surveillance. Thymosin Alpha-1 stimulates the differentiation of naive T-cell progenitors and promotes their maturation into functional effector and memory T cells. It also upregulates surface expression of T-cell markers including CD3, CD4, and CD8, increasing the functional competence of existing T-cell populations. In the context of cancer immunotherapy, Thymosin Alpha-1 activates dendritic cells (the primary antigen-presenting cells that initiate adaptive immune responses) and augments NK cell cytotoxicity against tumor cells. This has made it a subject of investigation as an adjunct to conventional oncological treatments, particularly in hepatocellular carcinoma, renal cell carcinoma, and non-small cell lung cancer. The clinical evidence base for Thymosin Alpha-1 is among the most substantial of any research peptide currently available. The synthetic form, thymalfasin, is approved in more than 35 countries (under the brand name Zadaxin) for the treatment of chronic hepatitis B, chronic hepatitis C, and as an immune enhancer in various disease states. Randomized controlled trials have demonstrated meaningful improvements in viral clearance rates in chronic hepatitis B and C when thymalfasin is combined with antiviral therapies. The compound has also been studied in sepsis, COVID-19-associated severe illness, as a vaccine adjuvant, and in oncological settings. The FDA has not approved thymalfasin, and it is currently used in the United States only in research and off-label compounded formulations. ## Dosage Route: Subcutaneous injection ### Schedule | Period | Dose | | --- | --- | | Immune support (maintenance) | 1.0-1.5 mg twice weekly for 4-8 weeks | | Hepatitis B (approved protocol) | 1.6 mg twice weekly for 26-52 weeks | | Hepatitis C (combined with IFN) | 1.6 mg twice weekly for 26-52 weeks | | Oncology adjunct | 1.6 mg 2-3x weekly per oncologist guidance | | Acute immune support | 1.6 mg daily for 3-5 days, then twice weekly | ### Reconstitution - Vial size: 10 mg - Water volume: 2 mL - Concentration: 5 mg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 0.5 mg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 1.0 mg | 0.20 mL | 20 units | | 1.5 mg | 0.30 mL | 30 units | | 1.6 mg | 0.32 mL | 32 units | ### Tips - Administer subcutaneously into the lower abdomen, outer thigh, or upper arm - Rotate injection sites with each injection - Use a 27-30 gauge needle - Pinch the skin to form a fold before inserting the needle at a 45-degree angle - Refrigerate at 2-8 degrees Celsius and protect from light - Use within 4-6 weeks of reconstitution -- do not freeze reconstituted solution ## Side Effects ### Common - Mild, transient redness, swelling, or discomfort at the injection site - Transient fatigue, mild fever, or general malaise in early administrations (consistent with immune activation, usually resolves within 24-48 hours) - Occasional mild headache ### Severe / Theoretical Risks - **Autoimmune exacerbation**: Because Ta1 broadly potentiates immune responses, there is theoretical concern about flares in individuals with pre-existing autoimmune conditions. Clinical evidence for this risk is limited, but caution is warranted. - **Cytokine release**: Robust immune activation in severely immunocompromised individuals who receive Ta1 may trigger more pronounced cytokine responses than anticipated. Clinical supervision is recommended in severe immunosuppression. ### Contraindications - Known autoimmune disease (use only under physician supervision; risk of immune exacerbation) - Known hypersensitivity to thymalfasin or any formulation component - Organ transplant recipients on immunosuppressive therapy (Ta1 may counter immunosuppressive regimens) - Pregnancy and breastfeeding (insufficient safety data) - Active severe infection without concurrent antimicrobial coverage ## FAQ ### What is Thymosin Alpha-1 and what does it do? Thymosin Alpha-1 is a 28-amino acid peptide naturally produced by the thymus gland that modulates both innate and adaptive immunity. It activates T cells, NK cells, and dendritic cells through Toll-like receptor signaling. It is approved in over 35 countries as Zadaxin for chronic hepatitis B and C. ### Is Thymosin Alpha-1 approved anywhere in the world? Yes. Thymalfasin (synthetic Thymosin Alpha-1) is approved in more than 35 countries under the brand name Zadaxin for chronic hepatitis B, chronic hepatitis C, and as an immune enhancer. The FDA has not approved it, so it is used in the United States only in research and off-label compounded formulations. ### What is the Thymosin Alpha-1 dosage for immune support? For general immune support, the maintenance dose is 1.0 to 1.5 mg injected subcutaneously twice weekly for 4 to 8 weeks. The approved hepatitis protocol uses 1.6 mg twice weekly for 26 to 52 weeks. Acute immune support protocols use 1.6 mg daily for 3 to 5 days, then twice weekly. ### What are Thymosin Alpha-1 side effects? Side effects are generally mild and include transient injection site reactions, temporary fatigue or low-grade fever in early administrations consistent with immune activation, and occasional mild headache. These immune activation symptoms typically resolve within 24 to 48 hours and diminish with continued use. ### Can Thymosin Alpha-1 worsen autoimmune conditions? Because Thymosin Alpha-1 broadly potentiates immune responses, there is theoretical concern about flares in individuals with pre-existing autoimmune conditions. Clinical evidence for this risk is limited, but caution is warranted. Use in autoimmune disease should only occur under physician supervision. ### How does Thymosin Alpha-1 help fight infections? Thymosin Alpha-1 enhances cell-mediated immune responses by promoting T-cell proliferation, increasing NK cell cytotoxicity, and activating dendritic cells for better antigen presentation. It upregulates CD3, CD4, and CD8 markers on T cells, increasing their functional competence against viral and intracellular bacterial pathogens. ## References 1. Tuthill C, Rios I, McBeath R. "Thymosin alpha 1: past clinical experience and future promise." *Ann N Y Acad Sci*, 2010. PMID: 20536460. https://pubmed.ncbi.nlm.nih.gov/20536460/ 2. Romani L, Bistoni F, Gaziano R, et al.. "Thymosin alpha 1 activates dendritic cells for antifungal Th1 resistance through toll-like receptor signaling." *Blood*, 2004. PMID: 14982877. https://pubmed.ncbi.nlm.nih.gov/14982877/ 3. Costantini C, Bellet MM, Pariano M, et al.. "A Reappraisal of Thymosin Alpha1 in Cancer Therapy." *Front Oncol*, 2019. PMID: 31555601. https://pubmed.ncbi.nlm.nih.gov/31555601/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Thymosin Alpha-1 has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/thymosin-alpha-1 --- # Thymalin **Thymalin (Thymic Peptide Bioregulator)** Category: Immune > Natural Thymic Peptide Bioregulator for Immune Support Thymalin is a natural peptide bioregulator extracted from the thymus glands of young calves, developed in the 1970s at the Institute of Gerontology in the Soviet Union. It supports T-cell differentiation, restores IL-2 production, and recalibrates immune function toward a more youthful baseline. Longitudinal research showed up to a 2-fold reduction in mortality in aging populations receiving thymalin therapy. ## Key Facts - **Primary target:** T-lymphocyte differentiation / gene expression via peptide binding to DNA and histone proteins; restores IL-2 and CD4+/CD8+/CD3+ T-cell populations (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC8654498/) - **Mechanism class:** Immunomodulator (thymic polypeptide bioregulator) with geroprotective activity (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC8365293/) - **Route of administration:** Intramuscular (IM) injection; subcutaneous (SubQ) also used (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC8654498/) - **Regulatory status:** Registered/approved in Russia as an immunomodulator (Ministry of Health reg. no. LS-000267, Feb 26 2010); NOT approved by FDA or EMA (research/unapproved in US & EU) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC8654498/) ## Overview Thymalin is a natural peptide bioregulator extracted from the thymus glands of young calves. It was developed in the 1970s at the Institute of Gerontology in the former Soviet Union by researchers Vladimir Khavinson and Vyacheslav Morozov, who were investigating the biological basis of immune aging and its connection to overall longevity. Thymalin belongs to a family of short peptide bioregulators that work not as blunt pharmacological agents but as precise regulators of gene expression in target tissues. The thymus gland is central to the education and maturation of T-lymphocytes, the immune cells responsible for adaptive immunity. With age, the thymus undergoes progressive involution, shrinking in size and reducing its output of naive T-cells. This thymic decline is considered a primary driver of immunosenescence, the gradual deterioration of immune function that makes older individuals more vulnerable to infection, cancer, and autoimmune dysregulation. Thymalin works by supplying the signaling peptides the aging thymus can no longer produce in sufficient quantities. At the molecular level, thymalin's short peptide sequences bind to double-stranded DNA and histone proteins, modulating gene expression in immune cells. This mechanism supports T-cell differentiation, restores interleukin-2 (IL-2) production, and regulates calcium-driven activation cascades in thymocytes and macrophages. The peptide reduces receptor-mediated and mitochondrial apoptosis in blood lymphocytes, extending their functional lifespan during replicative aging. In effect, it recalibrates the immune system toward a more youthful functional baseline rather than simply stimulating or suppressing it. Longitudinal research has demonstrated substantial geroprotective effects. Studies in aging populations showed up to a 2-fold reduction in mortality rates for subjects receiving thymalin therapy. A landmark study on COVID-19 in elderly patients, published in 2021, found that thymalin significantly improved immune status markers and clinical outcomes in older patients with severe disease. Thymalin has been clinically used for over 40 years in Russia and Eastern Europe and remains unavailable and unapproved in the United States and European Union. ## Dosage Route: Intramuscular (IM) or subcutaneous (SubQ) injection ### Schedule | Period | Dose | | --- | --- | | Standard protocol (per cycle) | 10 mg per day for 5-10 consecutive days; repeat every 6 months | | Maintenance protocol | 5 mg per day for 5 days; repeat every 3-4 months | ### Reconstitution - Vial size: Varies by supplier - Water volume: Sterile water for injection or bacteriostatic water - Concentration: Per vial labeling - Per unit: Varies by reconstitution volume ### Tips - Thymalin is supplied as a lyophilized powder; reconstitute with sterile water for injection or bacteriostatic water - Use within 5-7 days of reconstitution when refrigerated - Do not freeze reconstituted peptide - Standard protocol based on the Khavinson clinical protocol established through decades of Russian research ### Cycling - On period: 5-10 consecutive days - Off period: 3-6 months between cycles - Notes: Biannual dosing (every 6 months) is the standard protocol; some maintenance protocols use every 3-4 months at lower doses ## Side Effects ### Common - Injection site reactions (redness, mild swelling, brief discomfort) - Transient low-grade fever in the first day or two of a cycle (indicating immune activation) - Mild fatigue or malaise, particularly at the start of the first cycle - Occasional mild headache ### Severe / Theoretical Risks - **Allergic or hypersensitivity reactions**: Rare; may manifest as urticaria, pruritus, or in severe cases, anaphylaxis. - **Autoimmune flare**: Theoretical risk from broadly enhanced T-cell activity in individuals with pre-existing autoimmune conditions. - **Immune dysregulation in lymphoproliferative disorders**: Enhanced immune activity may be contraindicated in individuals with lymphoma or leukemia. ### Contraindications - Active autoimmune disease (stimulation of T-cell activity may worsen conditions such as rheumatoid arthritis, lupus, or multiple sclerosis) - Known allergy to thymus-derived preparations or bovine proteins - Active lymphoma or leukemia (immune stimulation contraindicated) - Pregnancy or breastfeeding (no safety data available) - Concurrent use of immunosuppressant medications (may antagonize therapeutic intent of those drugs) ## FAQ ### What is Thymalin and how does it work? Thymalin is a natural peptide bioregulator extracted from the thymus glands of young calves, developed in the 1970s in the Soviet Union. It supports T-cell differentiation, restores IL-2 production, and recalibrates immune function toward a more youthful baseline by supplying signaling peptides the aging thymus no longer produces. ### Can Thymalin extend lifespan? Longitudinal research showed up to a 2-fold reduction in mortality rates for aging populations receiving thymalin therapy. Long-term animal studies demonstrated slowed spontaneous tumor development and extended lifespan. However, these results come primarily from Soviet-era research with limited independent Western replication. ### What is the Thymalin dosage protocol? The standard protocol is 10 mg per day intramuscularly or subcutaneously for 5 to 10 consecutive days, repeated every 6 months. A maintenance protocol uses 5 mg per day for 5 days, repeated every 3 to 4 months. These cycles follow the Khavinson bioregulator philosophy of periodic recalibration. ### What are Thymalin side effects? Common effects include injection site reactions, transient low-grade fever in the first day or two indicating immune activation, mild fatigue at cycle start, and occasional headache. Serious risks include rare allergic reactions and theoretical autoimmune flare from broadly enhanced T-cell activity in predisposed individuals. ### Who should not use Thymalin? Thymalin is contraindicated for people with active autoimmune disease, known allergy to thymus-derived or bovine proteins, active lymphoma or leukemia, and those on immunosuppressant medications. The enhanced T-cell activity could worsen autoimmune conditions or antagonize immunosuppressive drug therapy. ### Is Thymalin available in the United States? Thymalin has been clinically used for over 40 years in Russia and Eastern Europe but remains unavailable and unapproved in the United States and European Union. The FDA has not reviewed it for any indication. It can only be obtained as a research compound in Western countries. ## References 1. Khavinson VKh, Morozov VG. "Geroprotective effect of thymalin and epithalamin." *Adv Gerontol*, 2002. PMID: 12577695. https://pubmed.ncbi.nlm.nih.gov/12577695/ 2. Khavinson VKh, Morozov VG. "Peptides of pineal gland and thymus prolong human life." *Neuro Endocrinol Lett*, 2003. PMID: 14523363. https://pubmed.ncbi.nlm.nih.gov/14523363/ 3. Khavinson VKh. "Peptides and Ageing." *Neuro Endocrinol Lett*, 2002. PMID: 12374906. https://pubmed.ncbi.nlm.nih.gov/12374906/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Thymalin has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/thymalin --- # Vilon **Vilon (L-Lys-L-Glu Dipeptide Bioregulator)** Category: Immune > Dipeptide Bioregulator for Immune Support Vilon (lysylglutamate) is a synthetic dipeptide composed of just two amino acids: lysine and glutamate. Despite its minimal structure, it is among the most biologically active peptide bioregulators known. It operates at the epigenetic level, binding to DNA and histone proteins to reactivate genes silenced by aging. It promotes T-lymphocyte proliferation, boosts IL-2 signaling, and provides vascular protective effects in animal research. ## Key Facts - **Molecular weight:** 275.30 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/7010502/property/MolecularFormula,MolecularWeight,IUPACName/JSON) - **Molecular formula:** C11H21N3O5 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/7010502/property/MolecularFormula,MolecularWeight,IUPACName/JSON) - **Sequence length:** 2 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/7010502/property/MolecularFormula,MolecularWeight,IUPACName/JSON) - **Primary target:** Genomic DNA / histone chromatin (epigenetic gene-expression modulation) and thymic/immune-cell targets driving T-lymphocyte (CD5/CD8) proliferation and IL-2 signaling (source: https://pubmed.ncbi.nlm.nih.gov/15105581/) - **Mechanism class:** Peptide bioregulator (short-peptide immunomodulator / geroprotector); acts as an epigenetic transcriptional regulator rather than via a classical receptor (source: https://pubmed.ncbi.nlm.nih.gov/10944717/) - **Route of administration:** Subcutaneous injection (also reported intranasal/peroral in Russian research); parenteral (source: https://pubmed.ncbi.nlm.nih.gov/11586413/) - **Regulatory status:** Not FDA/EMA approved; sold research-use-only in US/EU; clinical use only in Russia/Eastern Europe (no registered Western human trials) (source: https://pubmed.ncbi.nlm.nih.gov/10944717/) - **CAS number:** 45234-02-4 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/7010502/synonyms/JSON) ## Overview Vilon (L-Lys-L-Glu, or lysylglutamate) is a synthetic dipeptide composed of just two amino acids: lysine and glutamate. Despite its remarkably simple structure, it is considered one of the most biologically active peptide bioregulators known, demonstrating that molecular size does not limit biological potency. Vilon is modeled after signaling peptides found in thymus extracts and belongs to the same family of geroprotective bioregulators developed by the Khavinson group in the Soviet Union beginning in the 1970s. Vilon's primary mechanism of action operates at the epigenetic level. Its short peptide chain can bind directly to double-stranded DNA and histone proteins, modulating chromatin accessibility and reactivating genes that have been silenced through the epigenetic changes associated with aging. This capacity to alter gene expression without modifying the underlying DNA sequence places Vilon among a class of molecules with genuine epigenetic regulatory activity. Research has documented its ability to modulate the expression of more than 36 different genes in cardiac tissue, suggesting systemic regulatory reach from a structurally minimal molecule. On the immune side, Vilon promotes proliferation of T-lymphocyte subpopulations, particularly CD5 T-cells and cytotoxic CD8 T-cells. CD5 T-cells regulate immune self-tolerance and prevent autoimmune reactions, while CD8 T-cells form the primary antimicrobial and antiviral defense. Vilon also boosts interleukin-2 (IL-2) signaling, a key cytokine for T-cell activation and survival, and stimulates calcium-driven activation cascades in thymocytes and macrophages. The combined effect rebalances immune function rather than bluntly stimulating it. Beyond immune modulation, Vilon has demonstrated vascular protective effects in animal research. In kidney tissue, it reduces transforming growth factor-beta-1 (TGF-beta-1) concentration and decreases microvascular permeability, both of which are markers of age-related vascular dysfunction. Long-term animal studies have shown that Vilon treatment can prolong lifespan, slow spontaneous tumor development, and support metabolic and vascular homeostasis. As with other peptide bioregulators, human clinical data are limited and the peptide is not approved for use outside Russia and Eastern Europe. ## Dosage Route: Subcutaneous injection ### Schedule | Period | Dose | | --- | --- | | Per cycle | 67-670 mcg per day for 5 consecutive days; repeat every 3-6 months | ### Reconstitution - Vial size: Varies by supplier - Water volume: Bacteriostatic water per vial labeling - Concentration: 6.67 mg/mL is a common reconstitution target - Per unit: At 6.67 mg/mL, 1 unit (0.01 mL on U-100 syringe) delivers approximately 66.7 mcg ### Tips - Vilon is supplied as a lyophilized powder; reconstitute with bacteriostatic water to the desired concentration - Refrigerate at 2-8 degrees Celsius after reconstitution and use within 30 days - A common starting approach begins at the lower end (67-100 mcg/day) for the first cycle to assess tolerability - Use a U-100 insulin syringe for precise small-volume dosing - Administer in short cycles consistent with the bioregulator philosophy of periodic recalibration rather than chronic supplementation ### Cycling - On period: 5 consecutive days - Off period: 3-6 months between cycles - Notes: Short cycle administration every 3-6 months is the established protocol for bioregulator use ## Side Effects ### Common - Injection site reactions (local redness, minor bruising, brief discomfort) - Transient fatigue at cycle initiation - Mild headache (uncommon) - Slight increase in body temperature at treatment onset (consistent with immune activation) ### Severe / Theoretical Risks - **Immune hyperstimulation**: Theoretical risk from T-cell proliferative effects in immunologically sensitive individuals. - **Autoimmune aggravation**: Broad T-cell rebalancing could exacerbate existing autoimmune pathology in predisposed individuals. - **Unknown interactions with immunosuppressive therapies**: The full safety profile is not established given the limited scope of controlled Western clinical trials. ### Contraindications - Active autoimmune disease (enhanced T-cell activity may worsen symptoms) - Active lymphoproliferative malignancy (immune stimulation contraindicated) - Known hypersensitivity to lysine, glutamate, or any component of the formulation - Pregnancy or breastfeeding (insufficient safety data) - Concurrent immunosuppressant therapy (may directly counteract therapeutic intent) ## FAQ ### What is Vilon and how does it work? Vilon (L-Lys-L-Glu) is a synthetic dipeptide composed of just two amino acids that operates at the epigenetic level. It binds directly to DNA and histone proteins to reactivate genes silenced by aging. Despite its minimal structure, it modulates the expression of more than 36 different genes in cardiac tissue alone. ### How does Vilon support the immune system? Vilon promotes proliferation of T-lymphocyte subpopulations, particularly CD5 T-cells (regulating immune self-tolerance) and cytotoxic CD8 T-cells (antimicrobial defense). It boosts interleukin-2 signaling for T-cell activation and stimulates calcium-driven activation cascades in thymocytes and macrophages. ### What is the Vilon dosage? The standard protocol is 67 to 670 mcg per day subcutaneously for 5 consecutive days, repeated every 3 to 6 months. A common starting approach begins at the lower end of 67 to 100 mcg daily for the first cycle to assess tolerability. Use a U-100 insulin syringe for precise measurement. ### How does Vilon compare to Thymalin? Both are Khavinson bioregulators targeting immune function, but Vilon is a synthetic dipeptide while Thymalin is extracted from calf thymus. Vilon has additional documented vascular protective effects and gene expression modulation beyond immune function. Both use short cyclic dosing protocols repeated every 3 to 6 months. ### What are Vilon side effects? Common effects include injection site reactions, transient fatigue at cycle initiation, mild headache, and slight temperature increase at treatment onset consistent with immune activation. Theoretical risks include immune hyperstimulation and autoimmune aggravation in predisposed individuals. Side effects are generally mild and brief. ### Is Vilon FDA approved? Vilon is not FDA-approved and is unavailable through regulated pharmaceutical channels in the United States or European Union. The full safety profile is not established given the limited scope of controlled Western clinical trials. Human clinical data are limited and the peptide remains a research compound. ## References 1. Khavinson VKh, Morozov VG, Anisimov VN. "A synthetic dipeptide vilon (L-Lys-L-Glu) inhibits growth of spontaneous tumors [^1] and increases life span of mice." *Dokl Biol Sci*, 2000. PMID: 10944717. https://pubmed.ncbi.nlm.nih.gov/10944717/ 2. Lezhava TA, Monaselidze JR, Kadzhaia MV, et al.. "Bioregulator Vilon-induced reactivation of chromatin in cultured lymphocytes from old people." *Biogerontology*, 2004. PMID: 15105581. https://pubmed.ncbi.nlm.nih.gov/15105581/ 3. Ias'kevich VB, Deev AI, Buianovskaia OA. "Application of peptide bioregulator in complex treatment of elderly cancer patients." *Adv Gerontol*, 2005. PMID: 16075684. https://pubmed.ncbi.nlm.nih.gov/16075684/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Vilon has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/vilon --- # Kisspeptin-10 **Kisspeptin-10 (KISS1 C-Terminal Fragment)** Category: Sexual Health > Upstream Hormonal Activator for Sexual and Reproductive Health Kisspeptin-10 is the shortest biologically active fragment of the kisspeptin family, encoded by the KISS1 gene. It acts through GPR54 receptors on GnRH neurons in the hypothalamus to trigger pulsatile release of LH and FSH, driving endogenous testosterone production in men and ovulation in women. Human clinical trials have demonstrated dose-dependent increases in LH and testosterone, and the compound has research applications in hypogonadism and hypothalamic amenorrhea. ## Key Facts - **Molecular weight:** 1302.4 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/25240297/property/MolecularFormula,MolecularWeight/JSON) - **Molecular formula:** C63H83N17O14 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/25240297/property/MolecularFormula,MolecularWeight/JSON) - **Sequence length:** 10 amino acids (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/25240297/JSON?heading=Depositor-Supplied+Synonyms) - **Primary target:** KISS1R (GPR54) on hypothalamic GnRH neurons (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC3232613/) - **Mechanism class:** KISS1R (GPR54) agonist; stimulates hypothalamic GnRH release, driving pituitary LH/FSH secretion (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC3232613/) - **Half-life:** ~4 minutes (in vivo plasma; ~55 seconds in vitro) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC4507333/) - **Route of administration:** Intravenous (clinical research); subcutaneous injection (extrapolated research use) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC3232613/) - **Regulatory status:** Not FDA/EMA approved; investigational / research-use-only. Active clinical trials in reproductive medicine; no approved indication. (source: https://clinicaltrials.gov/search?term=kisspeptin) - **CAS number:** 374675-21-5 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/25240297/JSON?heading=CAS) ## Overview Kisspeptin-10 is the shortest biologically active fragment of the kisspeptin family of neuropeptides, encoded by the KISS1 gene. The KISS1 gene was originally identified as a metastasis suppressor in melanoma, but its endocrine role was established when researchers discovered that kisspeptin neurons in the hypothalamus serve as master regulators of the reproductive hormone axis. Kisspeptin-10 specifically refers to the 10-amino acid C-terminal fragment (Tyr-Asn-Trp-Asn-Ser-Phe-Gly-Leu-Arg-Phe-NH2) that retains full receptor binding activity. It acts through the G-protein coupled receptor GPR54 (also called KISS1R), which is expressed primarily on gonadotropin-releasing hormone (GnRH) neurons in the hypothalamus. The mechanistic cascade initiated by Kisspeptin-10 binding to GPR54 is well characterized. Receptor activation triggers the release of GnRH in pulsatile bursts, which in turn stimulates the anterior pituitary to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH). In men, LH drives Leydig cell production of testosterone; in women, the LH surge triggers ovulation and supports progesterone synthesis. This makes Kisspeptin-10 a proximal upstream activator of the entire gonadal hormone axis. Importantly, kisspeptin neurons integrate multiple peripheral signals (including leptin, estradiol, and metabolic status) into a single output: the GnRH pulse. This positions kisspeptin as a physiological gatekeeper of reproductive function responsive to body composition and nutritional state. Human clinical research on Kisspeptin-10 is more robust than for many research peptides. A landmark study published in the Journal of Clinical Endocrinology and Metabolism found that intravenous bolus doses of Kisspeptin-10 produced a rapid, dose-dependent rise in LH concentration, with maximal stimulation at 1 mcg/kg. Continuous IV infusion at 4 mcg/kg/hour for 22.5 hours raised mean LH significantly and increased serum testosterone from 16.6 to 24.0 nmol/L in healthy men. A lower dose infusion at 1.5 mcg/kg/hour increased LH pulse frequency from 0.7 to 1.0 pulses per hour. Additional research in men with type 2 diabetes and mild hypogonadism found that Kisspeptin-10 stimulated LH and testosterone secretion even in men with blunted baseline hormone output. Research at Imperial College London also found that kisspeptin administration increased activation in brain regions associated with sexual arousal, attraction, and olfactory cues in male volunteers, suggesting direct CNS effects beyond the hypothalamic-pituitary axis. Kisspeptin-10 research is particularly interesting in the context of hypothalamic amenorrhea (loss of menstrual function due to low body weight or stress), functional hypogonadotropic hypogonadism, and infertility. Unlike exogenous testosterone or gonadotropins, Kisspeptin-10 works by restoring the natural pulsatile signaling architecture rather than replacing downstream hormones. This makes it theoretically attractive as a means to preserve testicular or ovarian function and avoid the HPTA suppression associated with exogenous hormone use. ## Dosage Route: Subcutaneous injection (extrapolated); intravenous in clinical research ### Schedule | Period | Dose | | --- | --- | | IV bolus (research) | 1 mcg/kg, single or episodic | | IV continuous infusion | 1.5-4 mcg/kg/hr, up to 22.5 hours | | SC research use | 50-100 mcg, 2-3x/week | ### Reconstitution - Vial size: 10 mg - Water volume: 2 mL bacteriostatic water - Concentration: 5 mg/mL (5,000 mcg/mL) - Per unit: Each 0.01 mL (1 unit on a U-100 insulin syringe) = 50 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 50 mcg | 0.01 mL | 1 unit | | 100 mcg | 0.02 mL | 2 units | | 250 mcg | 0.05 mL | 5 units | ### Tips - The small injection volumes at typical doses require careful measurement with a precision insulin syringe - Consider diluting further (e.g., adding 10 mL BW for 1,000 mcg/mL) for easier dose measurement - Inject subcutaneously into the abdomen - Pulsatile dosing (not continuous) is critical to avoid receptor downregulation and paradoxical hormone suppression - Store reconstituted solution refrigerated and use within 28 days ## Side Effects ### Common - Flushing or warmth following injection - Mild nausea - Headache - Transient increases in libido or sexual arousal (expected pharmacodynamic effect) - Spontaneous erections in men (dose-dependent) ### Severe / Theoretical Risks - **Receptor desensitization with continuous use**: Sustained non-pulsatile kisspeptin stimulation paradoxically suppresses GnRH release through receptor downregulation; continuous use may ironically reduce testosterone rather than raise it. - **Hormonal overstimulation in women**: Supraphysiological LH stimulation risks ovarian hyperstimulation syndrome (OHSS) in women, particularly those with polycystic ovary syndrome; this is a potentially serious complication requiring medical management. - **Unknown long-term safety**: Human data is limited to relatively short research protocols; chronic effects on pituitary function, receptor sensitivity, and the reproductive axis are not established. ### Contraindications - Polycystic ovary syndrome (risk of ovarian hyperstimulation) - Pregnancy or breastfeeding - Hormone-sensitive cancers (breast, prostate, ovarian) - Active fertility treatment with gonadotropins (potential interaction) - Pediatric use (potential disruption of puberty timing) ## FAQ ### What is Kisspeptin-10 and what does it do? Kisspeptin-10 is the shortest biologically active fragment of the kisspeptin neuropeptide family. It acts through GPR54 receptors on GnRH neurons to trigger pulsatile release of LH and FSH, driving endogenous testosterone production in men and ovulation in women through natural hormonal signaling. ### Can Kisspeptin-10 increase testosterone naturally? Yes. Clinical research shows Kisspeptin-10 produces dose-dependent rises in LH concentration. Continuous IV infusion at 4 mcg/kg/hour increased serum testosterone from 16.6 to 24.0 nmol/L in healthy men. It works by restoring natural pulsatile signaling rather than replacing downstream hormones directly. ### How does Kisspeptin-10 compare to HCG or clomiphene? Kisspeptin-10 works upstream of both HCG and clomiphene by activating GnRH neurons directly. This preserves the entire natural pulsatile signaling architecture from hypothalamus through pituitary to gonads. It is theoretically more physiological but has less clinical evidence supporting long-term use. ### What are the side effects of Kisspeptin-10? Common effects include flushing, mild nausea, headache, transient increases in libido, and spontaneous erections in men. The most serious risk is receptor desensitization from continuous use, which paradoxically suppresses GnRH and reduces testosterone. Pulsatile dosing is critical to avoid this. ### Is Kisspeptin-10 safe for women? Women with polycystic ovary syndrome face particular risk because supraphysiological LH stimulation can trigger ovarian hyperstimulation syndrome. Kisspeptin-10 is also contraindicated during pregnancy, breastfeeding, and in women with hormone-sensitive cancers. Medical supervision is essential for female use. ### What is the correct Kisspeptin-10 dosage? Subcutaneous research doses are typically 50 to 100 mcg given two to three times weekly. Clinical research used IV bolus doses of 1 mcg/kg. Pulsatile dosing, not continuous, is critical to prevent receptor downregulation and paradoxical hormone suppression that defeats the purpose of treatment. ## References 1. Seminara SB, Messager S, Chatzidaki EE, et al.. "The GPR54 gene as a regulator of puberty." *N Engl J Med*, 2003. PMID: 14573733. https://pubmed.ncbi.nlm.nih.gov/14573733/ 2. de Roux N, Genin E, Carel JC, et al.. "Hypogonadotropic hypogonadism due to loss of function of the KiSS1-derived peptide receptor GPR54." *Proc Natl Acad Sci U S A*, 2003. PMID: 12944565. https://pubmed.ncbi.nlm.nih.gov/12944565/ 3. Dhillo WS, Chaudhri OB, Patterson M, et al.. "Kisspeptin-54 stimulates the hypothalamic-pituitary gonadal axis in human males." *J Clin Endocrinol Metab*, 2005. PMID: 16174713. https://pubmed.ncbi.nlm.nih.gov/16174713/ 4. George JT, Veldhuis JD, Roseweir AK, et al.. "Kisspeptin-10 is a potent stimulator of LH and increases pulse frequency in men." *J Clin Endocrinol Metab*, 2011. PMID: 21632807. https://pubmed.ncbi.nlm.nih.gov/21632807/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Kisspeptin-10 has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/kisspeptin-10 --- # Oxytocin **Oxytocin (Neuropeptide)** Category: Sexual Health > Neuropeptide for Sexual Response, Bonding, and Social Connection Oxytocin is a nine-amino acid neuropeptide produced in the hypothalamus and released by the posterior pituitary. It has dual release pathways: peripheral oxytocin drives uterine contractions and milk ejection, while central oxytocinergic signaling modulates sexual function, social bonding, stress response, and emotional memory. Controlled clinical trials using intranasal oxytocin have demonstrated enhanced orgasm intensity and sexual satiety in men, with women reporting increased relaxation and improved sexual communication. It is used clinically for labor induction (Pitocin) and is studied in sexual wellness and social neuroscience research. ## Key Facts - **Molecular weight:** 1007.2 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/439302) - **Molecular formula:** C43H66N12O12S2 (source: https://pubchem.ncbi.nlm.nih.gov/compound/439302) - **Sequence length:** 9 amino acids (source: https://pubchem.ncbi.nlm.nih.gov/compound/439302) - **Primary target:** Oxytocin receptor (OXTR), a Gq-coupled G-protein-coupled receptor (source: https://www.guidetopharmacology.org/GRAC/ObjectDisplayForward?objectId=369) - **Mechanism class:** Oxytocin receptor agonist / uterotonic (oxytocic agent) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=a9b62187-4141-487c-a9da-f42ad7f9b408&type=display) - **Half-life:** 3 to 5 minutes (plasma) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=a9b62187-4141-487c-a9da-f42ad7f9b408&type=display) - **Route of administration:** Intravenous infusion or intramuscular (FDA-approved obstetric use); intranasal or subcutaneous for off-label neuroscience/sexual-wellness use (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=a9b62187-4141-487c-a9da-f42ad7f9b408&type=display) - **Regulatory status:** FDA-approved (synthetic oxytocin, Pitocin) for antepartum labor induction/augmentation and postpartum control of uterine bleeding; sexual-wellness, social-bonding, and anxiety uses are off-label and not FDA-approved (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=a9b62187-4141-487c-a9da-f42ad7f9b408&type=display) - **CAS number:** 50-56-6 (source: https://pubchem.ncbi.nlm.nih.gov/compound/439302) ## Overview Oxytocin is a nine-amino acid neuropeptide produced in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the hypothalamus. It is stored and released by the posterior pituitary gland into the bloodstream, and it is also released directly within the brain from oxytocinergic neurons projecting to numerous brain regions. These two release pathways serve distinct functions: peripheral oxytocin drives physiological effects such as uterine contractions during labor and milk ejection during nursing, while central (brain) oxytocin modulates social behavior, stress response, emotional memory, and sexual function. The molecular structure of oxytocin was determined by Vincent du Vigneaud in 1953, work that earned the Nobel Prize in Chemistry in 1955. Synthetic oxytocin (Pitocin) has been used medically for decades to induce labor and control postpartum hemorrhage. More recently, scientific and clinical interest has expanded to oxytocin's roles in social bonding, anxiety regulation, and sexual response. Oxytocin levels rise during positive social contact, physical touch, and sexual activity, and peak concentrations are observed at orgasm in both men and women. This has led to popular descriptions of oxytocin as the love hormone or bonding hormone, a simplification that nonetheless reflects real and reproducible neuroscience. At the cellular level, oxytocin binds to its G-protein-coupled receptor (OXTR), which is expressed throughout the brain and body, including the hypothalamus, amygdala, brainstem, spinal cord, heart, kidney, uterus, and testes. In the context of sexual function, oxytocinergic neurons projecting to the spinal cord activate nitric oxide synthase (NOS), producing nitric oxide (NO). This signaling cascade facilitates penile erection in males and clitoral engorgement in females. Controlled clinical trials using intranasal oxytocin (which reaches the central nervous system via olfactory pathways, bypassing the blood-brain barrier) have demonstrated enhanced orgasm intensity in both sexes and increased sexual satiety in men. The research evidence for oxytocin's effect on orgasm quality appears more robust than its effect on initiating desire. The broader research literature on oxytocin and human sexual function is more nuanced than popular accounts suggest. Animal studies consistently support a facilitatory role in sexual behavior. Human clinical trials, particularly those examining effects on libido and sexual initiation with intranasal administration, have produced mixed results. Clinicians using oxytocin in sexual wellness settings typically administer it as a nasal spray or subcutaneous injection in the 30-60 minute window before anticipated sexual activity, targeting its acute neurochemical effects rather than any hormonal replacement-style mechanism. ## Dosage Route: Intranasal spray or subcutaneous injection; 30-60 minutes before activity ### Schedule | Period | Dose | | --- | --- | | Introductory (intranasal) | 10-12 IU (1-2 sprays), 30-60 min before activity | | Standard research dose | 24 IU intranasal, 30-60 min before activity | | Higher dose | 40 IU intranasal, 30-60 min before activity | | Subcutaneous (injectable) | 100-300 mcg, 30-60 min before activity | ### Reconstitution - Vial size: 2 mg - Water volume: 2 mL bacteriostatic water - Concentration: 1 mg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 100 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 100 mcg | 0.10 mL | 10 units on insulin syringe | | 200 mcg | 0.20 mL | 20 units | | 300 mcg | 0.30 mL | 30 units | ### Tips - Refrigerate reconstituted solution at 2-8 degrees Celsius; use within 4 weeks - Protect from light; oxytocin degrades with prolonged light exposure - For intranasal spray, tilt the head slightly forward and spray into each nostril while gently inhaling - Rotate nostrils with each dose to reduce local mucosal irritation with frequent use - Subcutaneous injections are delivered to the lower abdomen or lateral thigh - As-needed dosing (pre-activity rather than scheduled daily) is preferred to avoid receptor desensitization ## Side Effects ### Common - Nausea: mild, usually brief; more common at higher doses or in sensitive individuals - Headache: reported with both intranasal and subcutaneous routes, particularly at higher dose ranges - Nasal irritation: local mucosal irritation or transient congestion with repeated intranasal administration - Transient mood changes: some users report euphoria or increased sociability immediately post-administration; occasional reports of irritability or mild anxiety exist - Uterine contractions: a primary physiological action of peripheral oxytocin; this is a significant risk in pregnancy ### Severe / Theoretical Risks - **Hyponatremia (low sodium)**: Oxytocin has antidiuretic properties at higher doses and can cause water retention and dilutional hyponatremia. This is most relevant at clinical IV doses used in obstetrics but is a theoretical risk with high-dose injectable peptide use. - **Cardiovascular effects**: High doses can cause reflex tachycardia and hypotension via peripheral vasodilation. Clinically significant at obstetric doses; less established at research doses. - **Prostate effects in men**: Some clinicians advise against chronic daily use in men based on concerns about prostate tissue stimulation, though robust clinical data specific to low-dose peptide use in healthy men are lacking. ### Contraindications - Pregnancy (risk of premature or intensified uterine contractions) - Known allergy to oxytocin or any formulation component - Hyponatremia or conditions predisposing to low sodium levels - Severe cardiovascular disease - History of uterine surgery that may be sensitive to contractile agents ## FAQ ### What is oxytocin and what does it do? Oxytocin is a nine-amino acid neuropeptide produced in the hypothalamus that modulates sexual function, social bonding, stress response, and emotional memory. Peripheral oxytocin drives uterine contractions and milk ejection, while central oxytocin enhances orgasm intensity and social connection. ### Does oxytocin improve sexual function? Controlled clinical trials using intranasal oxytocin have demonstrated enhanced orgasm intensity in both sexes and increased sexual satiety in men. The evidence for oxytocin's effect on orgasm quality appears more robust than its effect on initiating desire. It is typically used 30 to 60 minutes before activity. ### How do you take oxytocin for sexual wellness? Oxytocin is administered as intranasal spray (10 to 40 IU) or subcutaneous injection (100 to 300 mcg) 30 to 60 minutes before anticipated sexual activity. As-needed dosing before activity is preferred over daily scheduling to avoid receptor desensitization that would reduce effectiveness over time. ### What are oxytocin side effects? Common side effects include mild nausea, headache, nasal irritation with intranasal use, transient mood changes, and uterine contractions (a significant risk in pregnancy). Serious risks include hyponatremia at higher doses, cardiovascular effects from vasodilation, and potential prostate tissue stimulation with chronic use. ### Is oxytocin safe during pregnancy? Oxytocin for sexual wellness purposes is contraindicated during pregnancy due to the risk of premature or intensified uterine contractions. Synthetic oxytocin (Pitocin) is used medically to induce labor, but only under direct obstetric supervision with continuous fetal monitoring in hospital settings. ### Is oxytocin FDA approved? Synthetic oxytocin (Pitocin) has been FDA-approved for decades to induce labor and control postpartum hemorrhage. However, its use for sexual wellness, social bonding, or anxiety reduction represents off-label application that has not been reviewed or approved by the FDA for those specific purposes. ## References 1. Kosfeld M, Heinrichs M, Zak PJ, et al.. "Oxytocin increases trust in humans." *Nature*, 2005. PMID: 15931222. https://pubmed.ncbi.nlm.nih.gov/15931222/ 2. Shamay-Tsoory SG, Fischer M, Dvash J, et al.. "Intranasal administration of oxytocin increases envy and schadenfreude (gloating)." *Biol Psychiatry*, 2009. PMID: 19640508. https://pubmed.ncbi.nlm.nih.gov/19640508/ 3. Hollander E, Bartz J, Chaplin W, et al.. "Oxytocin increases retention of social cognition in autism." *Biol Psychiatry*, 2007. PMID: 16904652. https://pubmed.ncbi.nlm.nih.gov/16904652/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Oxytocin has not been approved by the FDA for the indications described on this page. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/oxytocin --- # PT-141 **PT-141 (Bremelanotide)** Category: Sexual Health > FDA-Approved Central Nervous System Activator for Sexual Desire PT-141 (bremelanotide) is a synthetic cyclic heptapeptide derived from Melanotan 2 that selectively activates MC3R and MC4R receptors in the central nervous system. Unlike PDE5 inhibitors that act peripherally on genital blood flow, PT-141 acts centrally on the neural circuits governing sexual desire and arousal. It received FDA approval in 2019 as Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women, and is used off-label in men for desire-component erectile dysfunction. ## Key Facts - **Molecular weight:** 1025.2 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/9941379) - **Molecular formula:** C50H68N14O10 (source: https://pubchem.ncbi.nlm.nih.gov/compound/9941379) - **Sequence length:** 7 amino acids (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8c9607a2-5b57-4a59-b159-cf196deebdd9) - **Primary target:** Melanocortin receptors (MC1R and MC4R primary; also MC3R, MC5R, MC2R) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=8c9607a2-5b57-4a59-b159-cf196deebdd9) - **Mechanism class:** Melanocortin receptor agonist (nonselective) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=8c9607a2-5b57-4a59-b159-cf196deebdd9) - **Half-life:** 2.7 hours (range 1.9-4.0 hours), mean terminal half-life after single subcutaneous dose (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=8c9607a2-5b57-4a59-b159-cf196deebdd9) - **Route of administration:** Subcutaneous injection (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=8c9607a2-5b57-4a59-b159-cf196deebdd9) - **Regulatory status:** FDA-approved 2019 as Vyleesi for acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=8c9607a2-5b57-4a59-b159-cf196deebdd9) - **CAS number:** 189691-06-3 (source: https://pubchem.ncbi.nlm.nih.gov/compound/9941379) ## Overview PT-141, known generically as bremelanotide, is a synthetic cyclic heptapeptide derived from Melanotan 2 (MT-2). Its development emerged from an unexpected observation during early MT-2 clinical trials: the majority of male subjects reported spontaneous erections following administration. Researchers isolated the central nervous system mechanism responsible for this effect and developed a more targeted compound. Unlike MT-2, PT-141 is a cyclic peptide without the full melanocortin receptor activity profile of its predecessor, and it does not produce significant skin tanning under normal use conditions. PT-141 is a selective agonist at the melanocortin MC3R and MC4R receptors, which are expressed primarily within the central nervous system rather than at the genital tissue itself. This mechanism of action fundamentally distinguishes PT-141 from all prior treatments for sexual dysfunction. PDE5 inhibitors (sildenafil, tadalafil) and vasodilators act peripherally on genital blood flow. PT-141 acts centrally, on the neural circuits governing sexual desire and arousal within the brain itself. When PT-141 binds to MC4R in the hypothalamus and related limbic structures, it stimulates the release of dopamine and related neurochemicals involved in motivation and reward, effectively activating the brain's wanting and approach circuitry for sexual activity. This is why the compound can benefit individuals with low desire rather than solely vascular dysfunction. In 2019, the FDA approved bremelanotide under the brand name Vyleesi as an on-demand subcutaneous injection for premenopausal women with hypoactive sexual desire disorder (HSDD). This marked a milestone: the first centrally acting, non-hormonal pharmacological treatment approved specifically for sexual desire in women. The pivotal Phase 3 trials (RECONNECT studies) demonstrated statistically significant improvements in sexual desire scores and reductions in distress related to low desire compared to placebo. The responder rate in these trials was approximately 25 percent of treated women versus 17 percent in the placebo group, reflecting real but modest clinical benefit at the 1.75 mg approved dose. Off-label use of PT-141 in men is widespread and growing. Clinical data supporting efficacy in male sexual dysfunction are more limited than for women but consistent. Published studies and clinical observations suggest PT-141 is effective for erectile dysfunction, particularly in men who do not respond to or cannot tolerate PDE5 inhibitors, and in men whose dysfunction has a desire or psychogenic component rather than a purely vascular origin. The compound may augment the effect of PDE5 inhibitors when used in combination, though this approach has not been formally evaluated in large controlled trials. ## Dosage Route: Subcutaneous injection, 45-90 minutes before activity ### Schedule | Period | Dose | | --- | --- | | FDA-approved (women, HSDD) | 1.75 mg, 45 min before activity; max 1x/24h; max 8x/month | | Standard off-label (men) | 1.0-1.75 mg, 45-90 min before activity, as needed | | Conservative starting dose | 0.5-1.0 mg, 60 min before activity, as needed | | Maximum studied (research) | 1.75 mg per protocol | ### Reconstitution - Vial size: 10 mg - Water volume: 2 mL bacteriostatic water - Concentration: 5 mg/mL - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 0.5 mg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 0.5 mg | 0.10 mL | 10 units on insulin syringe | | 1.0 mg | 0.20 mL | 20 units | | 1.75 mg | 0.35 mL | 35 units | ### Tips - Swirl gently; do not vortex; the powder should dissolve fully within 1-2 minutes - Inject subcutaneously into the lower abdomen or outer thigh using a 29-31 gauge insulin syringe - Inject 45-90 minutes before anticipated sexual activity for optimal timing - Effects typically begin within 45-60 minutes and can persist for several hours; peak window of enhanced desire is typically 2-4 hours post-injection - Starting at lower doses (0.5-1.0 mg) substantially reduces nausea incidence - Refrigerate at 2-8 degrees Celsius; reconstituted solution is stable for approximately 4-6 weeks ## Side Effects ### Common - Nausea: the most frequently reported adverse effect, occurring in approximately 40 percent of subjects in Phase 3 clinical trials; usually mild to moderate and resolves within 1-2 hours - Flushing: typically brief and involves the face, neck, and upper chest; related to transient vasodilation via MC4R signaling; usually resolves within 30-60 minutes - Headache: mild to moderate; reported in approximately 11-12 percent of clinical trial subjects; responds to standard analgesics - Hyperpigmentation: focal darkening of the face, gums, and breasts has been reported with chronic repeated use; risk increases with dosing frequency beyond recommended guidelines - Transient blood pressure elevation: a mean systolic increase of approximately 6 mmHg and diastolic increase of 3 mmHg has been documented in trials, typically peaking within 30 minutes of injection and resolving within 12 hours in healthy subjects ### Severe / Theoretical Risks - **Serious cardiovascular events**: The blood pressure elevation, while generally modest in healthy individuals, can be clinically significant in persons with pre-existing hypertension or cardiovascular disease. - **Persistent hyperpigmentation**: Unlike temporary flushing, some individuals develop lasting darkening of skin and mucous membranes with chronic or high-frequency use. - **Potential interaction with antihypertensives**: PT-141 can potentiate blood pressure-lowering effects of antihypertensive medications. ### Contraindications - Known cardiovascular disease or uncontrolled hypertension - Current use of medications for hypertension (additive effects possible; consult physician) - Pregnancy (no safety data; avoid completely) - Known hypersensitivity to bremelanotide or formulation components - History of hyperpigmentation disorders or active skin conditions involving melanocytes ## FAQ ### What is PT-141 and how does it work? PT-141 (bremelanotide) is a synthetic cyclic heptapeptide that activates MC3R and MC4R receptors in the central nervous system. Unlike Viagra or Cialis which act on genital blood flow, PT-141 works centrally on brain circuits governing sexual desire and arousal by stimulating dopamine release in reward pathways. ### Is PT-141 FDA approved? Yes. PT-141 received FDA approval in 2019 as Vyleesi for premenopausal women with hypoactive sexual desire disorder (HSDD). It is the first centrally acting, non-hormonal treatment approved specifically for sexual desire in women. Off-label use in men is growing but not FDA-reviewed. ### What is the PT-141 dosage for men? Standard off-label doses for men range from 1.0 to 1.75 mg injected subcutaneously 45 to 90 minutes before anticipated activity. Conservative starting doses of 0.5 to 1.0 mg substantially reduce nausea incidence. Effects typically begin within 45 to 60 minutes and peak at two to four hours post-injection. ### What are PT-141 side effects? Nausea is the most common side effect, occurring in approximately 40% of clinical trial subjects. Other effects include flushing, headache, hyperpigmentation with chronic use, and transient blood pressure elevation averaging 6 mmHg systolic. Starting at lower doses significantly reduces nausea frequency. ### How does PT-141 compare to Viagra? PT-141 acts centrally on brain desire circuits while Viagra acts peripherally on genital blood flow. PT-141 is particularly effective for desire-component or psychogenic dysfunction, while Viagra targets vascular erectile dysfunction. Some clinicians use both together, though this combination lacks formal clinical evaluation. ### How often can you use PT-141? The FDA-approved label limits use to a maximum of once per 24 hours and no more than 8 times per month. These limits exist because chronic frequent use causes focal hyperpigmentation of the face, gums, and breasts. PT-141 is designed for on-demand use, not daily administration. ## References 1. Kingsberg SA, Clayton AH, Portman D, et al.. "Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials." *Obstet Gynecol*, 2019. PMID: 31599840. https://pubmed.ncbi.nlm.nih.gov/31599840/ 2. Diamond LE, Earle DC, Heiman JR, et al.. "An effect on the subjective sexual response in premenopausal women with sexual arousal disorder by bremelanotide (PT-141), a melanocortin receptor agonist [^3]." *J Sex Med*, 2006. PMID: 16839319. https://pubmed.ncbi.nlm.nih.gov/16839319/ 3. Pfaus JG, Sadiq B, Engel S, et al.. "The neurobiology of bremelanotide for the treatment of hypoactive sexual desire disorder in premenopausal women." *CNS Spectr*, 2022. PMID: 33455598. https://pubmed.ncbi.nlm.nih.gov/33455598/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. PT-141 is FDA-approved (as Vyleesi) only for hypoactive sexual desire disorder in premenopausal women. Off-label use in men or outside the approved indication has not been reviewed or approved by the FDA. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/pt-141 --- # Melanotan 1 **Melanotan 1 (Afamelanotide)** Category: Skin/Tanning > MC1R-Selective Tanning Peptide with FDA-Approved EPP Indication Melanotan 1 (afamelanotide) is a synthetic analog of alpha-MSH with enhanced receptor binding affinity and metabolic stability. It selectively activates MC1R on melanocytes, upregulating eumelanin production to produce photoprotective tanning with or without UV exposure. It is FDA-approved under the brand name Scenesse as a bioresorbable implant for prevention of phototoxicity in erythropoietic protoporphyria (EPP), making it one of the few peptides with genuine regulatory approval. ## Key Facts - **Molecular weight:** 1646.8 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/16197727) - **Molecular formula:** C78H111N21O19 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16197727) - **Sequence length:** 13 amino acids (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=94f53286-11dd-7fbb-e053-2a95a90a7c48) - **Primary target:** Melanocortin 1 receptor (MC1R) (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=94f53286-11dd-7fbb-e053-2a95a90a7c48) - **Mechanism class:** Melanocortin 1 receptor (MC1R) agonist; synthetic alpha-MSH analog (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=94f53286-11dd-7fbb-e053-2a95a90a7c48) - **Half-life:** ~15 hr (subcutaneous controlled-release implant) (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=94f53286-11dd-7fbb-e053-2a95a90a7c48) - **Route of administration:** Subcutaneous bioresorbable implant (FDA-approved); subcutaneous injection (research/off-label) (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=94f53286-11dd-7fbb-e053-2a95a90a7c48) - **Regulatory status:** FDA-approved (Scenesse), Oct 2019, for increasing pain-free light exposure in adults with erythropoietic protoporphyria (EPP); EMA-approved Jan 2015 for same indication (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=94f53286-11dd-7fbb-e053-2a95a90a7c48) - **CAS number:** 75921-69-6 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16197727) ## Overview Melanotan 1, known generically as afamelanotide, is a synthetic analog of alpha-melanocyte stimulating hormone (alpha-MSH). It was developed at the University of Arizona in the 1980s as part of a research program aimed at creating a pharmacological tanning agent that could reduce UV-induced skin damage. The peptide differs from native alpha-MSH by two structural modifications: a substitution of norleucine for methionine at position 4, and a D-isomer phenylalanine at position 7. These changes substantially increase receptor binding affinity and metabolic stability, giving afamelanotide a much longer effective half-life than the endogenous hormone. Melanotan 1 acts as a selective agonist at the melanocortin 1 receptor (MC1R), which is expressed on the surface of melanocytes, the pigment-producing cells of the skin. MC1R activation triggers a rise in intracellular cyclic AMP (cAMP) and subsequent activation of cAMP-dependent protein kinase A (PKA). This cascade upregulates the transcription factor MITF and increases the expression and activity of melanogenic enzymes, particularly tyrosinase. The net effect is a shift in melanin production toward eumelanin, the brown-black pigment that provides the most photoprotective qualities, as opposed to phaeomelanin, the red-yellow pigment associated with fair, UV-sensitive skin. Critically, this pigmentation occurs with or without UV exposure, though ultraviolet light acts synergistically to amplify the tanning response. The clinical development of afamelanotide is among the most complete of any research peptide. Phase I studies established safety at subcutaneous doses of 0.08-0.16 mg/kg. Phase II and III trials demonstrated both efficacy and a defined regulatory use. In tanning research, studies published in JAMA Dermatology found that subjects receiving Melanotan 1 combined with UV-B light had 47% fewer sunburn cells and significantly enhanced tanning compared to UV-B alone. The compound received its first regulatory approval from the Italian Medicines Agency (AIFA) in May 2010, followed by European Medicines Agency (EMA) approval in January 2015 under the brand name Scenesse, specifically indicated for prevention of phototoxicity in adults with erythropoietic protoporphyria (EPP), a rare genetic disorder causing severe pain upon sun exposure. The U.S. FDA approved Scenesse in October 2019 for the same indication, making afamelanotide one of the few peptides with a genuine FDA approval for a specific medical condition. The EPP indication is distinct from cosmetic tanning use. People with EPP cannot tolerate any sunlight exposure without pain due to accumulation of protoporphyrin IX in the skin. Afamelanotide dramatically increases their pain-free light exposure time. The approved delivery method for EPP treatment is a bioresorbable implant (16 mg) placed subcutaneously, not self-injection. Research-grade injectable Melanotan 1 sold as a peptide is chemically identical but its use for cosmetic tanning represents off-label, unapproved self-administration outside the controlled clinical framework. ## Dosage Route: Subcutaneous injection; bioresorbable implant (FDA-approved EPP indication) ### Schedule | Period | Dose | | --- | --- | | Phase I research | 0.08-0.16 mg/kg, daily x 10 days | | EPP approved (Scenesse) | 16 mg implant, every 2 months | | Cosmetic research | 0.25-1 mg SC, daily | | Conservative start | 0.25 mg SC, daily (first week) | ### Reconstitution - Vial size: 10 mg - Water volume: 10 mL bacteriostatic water - Concentration: 1 mg/mL - Per unit: Each 0.25 mL = 0.25 mg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 0.25 mg | 0.25 mL | 25 units | | 0.50 mg | 0.50 mL | 50 units | | 1.0 mg | 1.00 mL | 100 units | ### Tips - Use a 29-31 gauge insulin syringe; inject subcutaneously into abdominal fat - Rotate injection sites to avoid lipohypertrophy - Melanotan 1 works synergistically with UV light; low-level sun or tanning bed exposure amplifies the tanning response - Pigmentation begins within 1-2 weeks and peaks 4-6 weeks after starting - Store reconstituted solution refrigerated and use within 28 days ## Side Effects ### Common - Nausea (very common, particularly at higher doses or within the first injections; may affect more than 10% of users) - Flushing and facial warmth - Fatigue and yawning - Headache - Decreased appetite - Spontaneous erections in men (less common with MT-1 than MT-2 due to MC1R selectivity, but reported) - Darkening of existing moles ### Severe / Theoretical Risks - **Mole changes and melanoma risk**: Multiple case reports in fair-skinned individuals document new moles, changes in existing moles, and at least several cases of melanoma associated with Melanotan use; the MC1R pathway directly drives melanocyte activity, which could promote malignant transformation in atypical nevi; this risk is considered real and not merely theoretical. - **Unregulated pigmentation distribution**: Pigmentation may develop unevenly across the body; areas with existing nevi may darken disproportionately. - **Cardiovascular effects**: Alpha-MSH receptors are present in cardiovascular tissue; high-dose melanocortin stimulation has been associated with transient blood pressure changes. - **Unknown long-term oncologic risk**: Chronically elevated MC1R stimulation in the absence of supervised dermatologic monitoring carries an unquantified skin cancer risk, particularly in individuals with fair skin, red hair, or a family history of melanoma. ### Contraindications - Personal or family history of melanoma or other skin cancers - Multiple or atypical nevi (dysplastic nevus syndrome) - Fitzpatrick skin types I-II with high UV sensitivity (highest risk of adverse pigmentation outcomes) - Pregnancy or breastfeeding - Hypersensitivity to melanocortin analogs ## FAQ ### What is Melanotan 1 and is it FDA approved? Melanotan 1 (afamelanotide) is a synthetic analog of alpha-MSH that selectively activates MC1R on melanocytes to produce photoprotective tanning. It is FDA-approved under the brand name Scenesse as a bioresorbable implant specifically for preventing phototoxicity in erythropoietic protoporphyria, a rare genetic disorder. ### How does Melanotan 1 cause tanning? Melanotan 1 activates melanocortin 1 receptors on melanocytes, triggering a cAMP cascade that upregulates tyrosinase and shifts melanin production toward eumelanin, the protective brown-black pigment. This tanning occurs with or without UV exposure, though ultraviolet light acts synergistically to amplify the response. ### What is the difference between Melanotan 1 and Melanotan 2? Melanotan 1 selectively targets MC1R for tanning with minimal sexual side effects. Melanotan 2 non-selectively activates MC1R, MC3R, MC4R, and MC5R, causing tanning plus spontaneous erections, appetite suppression, and other effects. Only Melanotan 1 has received FDA approval for any indication. ### What are Melanotan 1 side effects? Common side effects include nausea (affecting over 10% of users), flushing, fatigue, headache, decreased appetite, and darkening of existing moles. Serious risks include changes to moles that mimic melanoma, unregulated pigmentation distribution, and unknown long-term skin cancer risk from chronic MC1R stimulation. ### How long does it take for Melanotan 1 to work? Pigmentation typically begins within one to two weeks of starting injections and peaks at four to six weeks. The tanning effect builds gradually with continued use. Results vary significantly by individual skin type, with Fitzpatrick types III through V generally responding more predictably than very fair skin. ### Is Melanotan 1 safe for people with moles? Melanotan 1 is contraindicated for individuals with multiple or atypical nevi, personal or family history of melanoma, or dysplastic nevus syndrome. The peptide stimulates melanocyte activity broadly, and multiple case reports document new moles and concerning mole changes associated with melanocortin peptide use. ## References 1. Langendonk JG, Balwani M, Anderson KE, et al.. "Afamelanotide for Erythropoietic Protoporphyria." *N Engl J Med*, 2015. PMID: 26132941. https://pubmed.ncbi.nlm.nih.gov/26132941/ 2. Lim HW, Grimes PE, Agbai O, et al.. "Afamelanotide and narrowband UV-B phototherapy for the treatment of vitiligo: a randomized multicenter trial." *JAMA Dermatol*, 2015. PMID: 25230094. https://pubmed.ncbi.nlm.nih.gov/25230094/ 3. Biolcati G, Marchesini E, Sorge F, et al.. "Long-term observational study of afamelanotide in 115 patients with erythropoietic protoporphyria." *Br J Dermatol*, 2015. PMID: 25494545. https://pubmed.ncbi.nlm.nih.gov/25494545/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Melanotan 1 is approved by the FDA only for the treatment of erythropoietic protoporphyria under the brand name Scenesse and is not approved for cosmetic tanning or any other purpose. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/melanotan-1 --- # Melanotan 2 **Melanotan 2 (MT-2)** Category: Skin/Tanning > Non-Selective Melanocortin Peptide for Tanning and Skin Pigmentation Melanotan 2 (MT-2) is a synthetic analog of alpha-MSH that acts as a non-selective agonist at MC1R, MC3R, MC4R, and MC5R. MC1R activation drives eumelanin production and skin darkening; MC4R agonism produces spontaneous erections and appetite suppression. Unlike Melanotan 1, MT-2 has not received FDA approval for any indication. It is widely used off-label for cosmetic tanning and was the precursor compound from which PT-141 was developed. ## Key Facts - **Molecular weight:** 1024.2 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/92432/property/MolecularFormula,MolecularWeight/JSON) - **Molecular formula:** C50H69N15O9 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/92432/property/MolecularFormula,MolecularWeight/JSON) - **Sequence length:** 7 amino acids (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/92432/synonyms/JSON) - **Primary target:** Melanocortin receptors MC1R, MC3R, MC4R, MC5R (non-selective; no significant MC2R) (source: https://www.guidetopharmacology.org/services/ligands/1323/interactions) - **Mechanism class:** Non-selective melanocortin receptor agonist (synthetic cyclic analog of alpha-MSH) (source: https://www.guidetopharmacology.org/services/ligands/1323/interactions) - **Route of administration:** Subcutaneous injection (source: https://pubmed.ncbi.nlm.nih.gov/8637402/) - **Regulatory status:** Not FDA-approved for any indication; unapproved for human use, sold research-use-only. Also not approved by EMA, MHRA, or TGA. (source: https://en.wikipedia.org/wiki/Melanotan_II) - **CAS number:** 121062-08-6 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/92432/synonyms/JSON) ## Overview Melanotan 2 (MT-2) is a synthetic analogue of alpha-melanocyte-stimulating hormone (alpha-MSH), a naturally occurring peptide that regulates skin pigmentation and other physiological processes. Developed originally at the University of Arizona in the 1980s as a potential tool for studying melanogenesis, MT-2 was designed to be a more potent and metabolically stable version of alpha-MSH. Researchers hoped the compound could reduce UV exposure required for tanning, thereby lowering skin cancer risk associated with sun-seeking behavior. MT-2 acts as a non-selective agonist at multiple melanocortin receptors: MC1R, MC3R, MC4R, and MC5R. Activation of MC1R on melanocytes triggers the upregulation of eumelanin production, the dark brown-black pigment responsible for skin darkening. Because MT-2 binds all four receptor subtypes rather than selectively targeting MC1R, it produces a range of effects beyond pigmentation, including spontaneous erections (via MC4R in the central nervous system), appetite suppression (MC3R and MC4R), and changes in sebaceous gland activity (MC5R). Early phase I clinical trials demonstrated increases in skin reflectance and visual pigmentation scores in subjects receiving subcutaneous MT-2 injections. In one landmark pilot trial published in Life Sciences (Dorr et al., 1996), 3 normal male volunteers experienced measurable tanning after only five low doses administered every other day. The same study documented that the male volunteers developed spontaneous penile erections after administration, an unexpected finding that eventually led researchers to develop PT-141 (bremelanotide) as a targeted sexual dysfunction treatment. Despite promising early data, MT-2 has never completed the full FDA approval process for any indication, and it remains unapproved for human therapeutic use in the United States, European Union, and most other jurisdictions. The compound is available through research peptide vendors and is widely used off-label by individuals seeking accelerated tanning, particularly those who tan poorly due to fair skin phenotypes (Fitzpatrick types I-II). Users must understand that the long-term safety profile of MT-2 is incompletely characterized, that the compound can cause changes to existing moles and nevi that mimic melanoma, and that its use is not endorsed by dermatology or endocrinology professional bodies. Responsible use requires pre-use dermatological evaluation and periodic skin monitoring throughout any course of administration. ## Dosage Route: Subcutaneous injection into lower abdomen or lateral thigh ### Schedule | Period | Dose | | --- | --- | | Loading (Week 1-2) | 0.25 mg once daily, evening | | Maintenance | 0.5-1.0 mg, 2-3x weekly | | Minimal effective (research) | 0.025 mg/kg every other day | | Maximum studied | 0.03 mg/kg per study day | ### Reconstitution - Vial size: 10 mg - Water volume: 2 mL bacteriostatic water - Concentration: 5 mg/mL (5,000 mcg/mL) - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 0.5 mg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 0.25 mg | 0.025 mL | 2.5 units on insulin syringe | | 0.5 mg | 0.05 mL | 5 units | | 1.0 mg | 0.10 mL | 10 units | ### Tips - Inject the water slowly against the side of the vial; do not shake, swirl gently to avoid denaturing the peptide - Injecting in the evening can reduce the impact of nausea, which tends to occur within 1-2 hours of dosing - Injections are administered subcutaneously into the lower abdomen or lateral thigh using a 27-31 gauge insulin syringe - Store reconstituted vials refrigerated at 2-8 degrees Celsius; use within 4-6 weeks - Alternatively, add 2 mL BAC water for a 5 mg/mL solution to make smaller doses easier to measure precisely ## Side Effects ### Common - Nausea: the most frequently reported side effect, occurring at nearly all dose levels in clinical trials; typically mild and transient, resolving within 1-2 hours - Flushing and facial redness: occurs shortly after injection due to vasodilatory effects mediated through melanocortin receptors in vascular smooth muscle - Spontaneous erections in men: a predictable pharmacological effect of MC4R agonism, often accompanied by a stretching and yawning complex; duration can range from 1-5 hours depending on dose - Fatigue and lethargy: reported by some users during the loading phase, typically resolving as the body adapts - Appetite suppression: MC3R and MC4R agonism reduces appetite in many users; this effect can be significant at higher doses - Changes in moles and skin lesions: MT-2 stimulates pigmentation broadly, including in pre-existing nevi; moles may darken or increase in size ### Severe / Theoretical Risks - **Melanoma risk**: Current evidence does not establish a direct causal link between MT-2 and melanoma development. However, the peptide stimulates melanocyte proliferation, and any increased cancer risk in users is likely mediated through increased UV-seeking behavior. Pre-use dermatological evaluation and ongoing skin monitoring are strongly advised. - **Cardiovascular effects**: MT-2 can cause transient increases in blood pressure and heart rate. These effects are generally mild but potentially significant in individuals with pre-existing cardiovascular disease. - **Psychiatric effects**: Anecdotal reports of mood changes and, rarely, psychiatric symptoms with high-dose use. ### Contraindications - Known or suspected melanoma or other skin cancers - Personal or family history of melanoma - Pregnancy or breastfeeding - Uncontrolled hypertension - Cardiovascular disease - Immunosuppression - Children and adolescents ## FAQ ### What is Melanotan 2 and how does it work? Melanotan 2 (MT-2) is a synthetic alpha-MSH analog that non-selectively activates MC1R, MC3R, MC4R, and MC5R receptors. MC1R activation drives skin darkening through eumelanin production. MC4R agonism causes spontaneous erections and appetite suppression. It has never received FDA approval for any indication. ### Does Melanotan 2 cause erections? Yes. In the pilot phase-I trial (Dorr et al., Life Sciences, 1996), the male volunteers developed spontaneous penile erections after MT-2 administration. This effect is driven by MC4R agonism in the central nervous system. This unexpected finding led researchers to develop PT-141 (bremelanotide) as a targeted sexual dysfunction treatment. ### What is the Melanotan 2 dosage for tanning? Loading doses typically start at 0.25 mg once daily for one to two weeks. Maintenance doses range from 0.5 to 1.0 mg administered two to three times weekly. Injecting in the evening can reduce nausea impact. The peptide is reconstituted with bacteriostatic water and injected subcutaneously. ### Is Melanotan 2 dangerous? MT-2 carries significant risks including mole changes that can mimic melanoma, cardiovascular effects like blood pressure and heart rate changes, and psychiatric effects at high doses. It stimulates melanocyte proliferation broadly, and pre-use dermatological evaluation with ongoing skin monitoring is strongly recommended. ### How long does Melanotan 2 tanning last? Tanning from MT-2 typically becomes visible within five to seven days and intensifies over two to four weeks. After discontinuation, the tan fades gradually over several weeks to months as tanned skin cells naturally turn over. Maintenance doses are needed to sustain the pigmentation effect long-term. ### What are common Melanotan 2 side effects? The most common side effect is nausea, occurring at nearly all dose levels. Other effects include facial flushing, spontaneous erections in men, fatigue, appetite suppression, and changes in existing moles. These side effects are dose-dependent and most pronounced during the initial loading phase. ## References 1. Dorr RT, Lines R, Levine N, et al.. "Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study." *Life Sci*, 1996. PMID: 8637402. https://pubmed.ncbi.nlm.nih.gov/8637402/ 2. Hadley ME, Dorr RT. "Melanocortin peptide therapeutics: historical milestones, clinical studies and commercialization." *Peptides*, 2006. PMID: 16412534. https://pubmed.ncbi.nlm.nih.gov/16412534/ 3. Wessells H, Fuciarelli K, Hansen J, et al.. "Melanocortin receptor agonists, penile erection, and sexual motivation: human studies with Melanotan II." *Int J Impot Res*, 2000. PMID: 11035391. https://pubmed.ncbi.nlm.nih.gov/11035391/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Melanotan 2 has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/melanotan-2 --- # Gonadorelin **Gonadorelin (GnRH)** Category: Hormonal > Bioidentical GnRH Peptide for Hormonal Health Gonadorelin is a synthetic decapeptide structurally identical to endogenous gonadotropin-releasing hormone (GnRH). It stimulates the anterior pituitary to release LH and FSH in a pattern-dependent manner -- pulsatile administration supports the HPG axis, while continuous exposure suppresses it. FDA-approved for HPG axis evaluation and ovulation induction, it is also widely used off-label to preserve testicular function during testosterone replacement therapy. ## Key Facts - **Molecular weight:** 1182.3 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/638793) - **Molecular formula:** C55H75N17O13 (source: https://pubchem.ncbi.nlm.nih.gov/compound/638793) - **Sequence length:** 10 (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=1451663c-b85a-4b45-8b27-6d572d0032f9) - **Primary target:** GnRH receptor (gonadotropin-releasing hormone receptor, GnRHR) on anterior pituitary gonadotrophs (source: https://www.guidetopharmacology.org/GRAC/ObjectDisplayForward?objectId=256) - **Mechanism class:** GnRH receptor agonist (gonadotropin-releasing hormone analogue) (source: https://www.ferring.ca/media/1230/lutrepulse-pm-control-no-127836-3-2mg-and-0-8-mg-en_17aug2010.pdf) - **Half-life:** 10 to 40 minutes (terminal elimination); distribution half-life ~2 to 10 minutes (source: https://www.ferring.ca/media/1230/lutrepulse-pm-control-no-127836-3-2mg-and-0-8-mg-en_17aug2010.pdf) - **Route of administration:** Intravenous or subcutaneous injection; pulsatile SQ infusion pump for therapeutic use (source: https://www.rxlist.com/factrel-drug.htm) - **Regulatory status:** FDA-approved (human) 1982 as Factrel for evaluating anterior pituitary gonadotrope function (GnRH stimulation test); now discontinued/withdrawn from US market. Separate veterinary FDA approval exists. Not currently marketed for human use. (source: https://pubchem.ncbi.nlm.nih.gov/compound/638793) - **CAS number:** 33515-09-2 (source: https://pubchem.ncbi.nlm.nih.gov/compound/638793) ## Overview Gonadorelin is a synthetic decapeptide that is structurally identical to endogenous gonadotropin-releasing hormone (GnRH), the hypothalamic hormone responsible for regulating the hypothalamic-pituitary-gonadal (HPG) axis. In its natural pulsatile form, GnRH signals the anterior pituitary to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which in turn stimulate the gonads to produce testosterone, estrogen, progesterone, and support gamete development. Because gonadorelin is bioidentical to the natural hormone, it provides a pharmacologically clean method of engaging this axis without introducing synthetic hormones directly. The pharmacological behavior of gonadorelin is highly dependent on the pattern of administration. Pulsatile delivery (mimicking the body's natural 60 to 120-minute secretion intervals) stimulates LH and FSH release from the pituitary, which is the basis for its use in hypogonadotropic hypogonadism, delayed puberty, and infertility treatment. Continuous or non-pulsatile exposure, by contrast, leads to GnRH receptor desensitization and a paradoxical suppression of LH and FSH, which is the mechanism exploited by long-acting GnRH agonists used in prostate cancer and endometriosis. Gonadorelin itself has a very short half-life (distribution half-life of 2 to 10 minutes; terminal half-life of 10 to 40 minutes), making continuous suppression unlikely at typical research doses. In men undergoing testosterone replacement therapy (TRT), gonadorelin has attracted substantial clinical interest as a means of preserving endogenous testosterone production and maintaining testicular size and function. Exogenous testosterone suppresses LH and FSH, leading to testicular atrophy and impaired spermatogenesis. Intermittent gonadorelin administration can stimulate the testes directly via the LH-receptor axis, potentially preserving fertility and testicular volume during TRT. This application is actively studied and represents one of the most common off-label uses of gonadorelin in the United States. Gonadorelin has established FDA-approved uses: it is indicated for the evaluation of hypothalamic-pituitary-gonadal axis function (the GnRH stimulation test) and for inducing ovulation in women with hypothalamic amenorrhea. These approvals give gonadorelin a more defined regulatory standing than many peptides used in research settings. ## Dosage Route: Intravenous (IV) bolus or subcutaneous (SQ) injection; pulsatile SQ infusion pump for therapeutic use ### Schedule | Period | Dose | | --- | --- | | Diagnostic (GnRH stimulation test) | 100 mcg adults / 2.5 mcg/kg children, single IV bolus | | Ovulation induction (pulsatile pump) | 5-20 mcg per pulse every 90-120 min via SQ infusion pump | | TRT adjunct (research protocol) | 50-100 mcg, 2-3x weekly SQ | | Hypogonadotropic hypogonadism | 100-250 mcg, 2-3x weekly SQ or IM | ### Reconstitution - Vial size: 2 mg - Water volume: 2 mL bacteriostatic water - Concentration: 1 mg/mL (1,000 mcg/mL) - Per unit: Each 0.1 mL (10 units on a U-100 insulin syringe) = 100 mcg ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 50 mcg | 0.05 mL | 5 units | | 100 mcg | 0.10 mL | 10 units | | 250 mcg | 0.25 mL | 25 units | ### Tips - Pulsatile delivery mimicking the hypothalamic rhythm of 60-120 minute intervals is most effective for sustained LH and FSH release - Due to gonadorelin's very short half-life (2-40 minutes), standard SQ injections 2-3x weekly maintain pulsatile signaling without continuous suppression - The first IV administration should occur in a clinical setting with emergency equipment available due to rare anaphylaxis risk - For ovulation induction, a portable infusion pump calibrated to deliver timed pulses is required - Rotate subcutaneous injection sites with each administration ## Side Effects ### Common - Injection site reactions (redness, swelling, mild pain at the subcutaneous administration site) - Flushing, headache, and mild nausea immediately following IV bolus administration (typically transient, resolving within 30 minutes) - Abdominal discomfort in women using gonadorelin for ovulation induction - Ovarian hyperstimulation syndrome (OHSS) in women with ovarian sensitivity: swollen, painful ovaries and fluid accumulation ### Severe / Theoretical Risks - **Anaphylaxis**: Although rare, severe allergic reactions have been reported. The first administration should occur in a clinical setting with emergency equipment available. - **Severe OHSS**: In women undergoing infertility treatment, severe hyperstimulation can result in serious fluid shifts, thromboembolism, and organ dysfunction requiring hospitalization. - **Luteal phase defect or multiple pregnancy**: When used for ovulation induction without proper monitoring, luteal phase abnormalities or multiple gestation may occur. ### Contraindications - Ovarian cysts or conditions that could be exacerbated by gonadotropin stimulation (in women) - Hypersensitivity to gonadorelin or any component of the formulation - Pregnancy (except as specifically indicated in assisted reproduction protocols under specialist supervision) - Hormone-sensitive cancers (gonadorelin-stimulated sex hormone production may worsen certain malignancies) - Any condition where sex hormone elevation is contraindicated ## FAQ ### What is Gonadorelin and what is it used for? Gonadorelin is a synthetic decapeptide structurally identical to endogenous gonadotropin-releasing hormone (GnRH). FDA-approved for HPG axis evaluation and ovulation induction, it is widely used off-label to preserve testicular function and fertility during testosterone replacement therapy by stimulating natural LH and FSH production. ### How does Gonadorelin help during TRT? Exogenous testosterone suppresses LH and FSH, causing testicular atrophy and impaired spermatogenesis. Gonadorelin administered 2 to 3 times weekly stimulates the pituitary to release LH, which directly activates Leydig cell testosterone production, potentially preserving testicular size, function, and fertility during TRT. ### What is the Gonadorelin dosage for TRT preservation? The typical TRT adjunct research protocol is 50 to 100 mcg subcutaneously two to three times weekly. For hypogonadotropic hypogonadism, 100 to 250 mcg is used two to three times weekly. Gonadorelin's very short half-life of 2 to 40 minutes means standard injections maintain pulsatile signaling without continuous suppression. ### What are Gonadorelin side effects? Common side effects include injection site reactions, flushing, headache, and mild nausea after IV administration. In women, ovarian hyperstimulation syndrome is a significant risk. Rare but serious anaphylaxis has been reported, so the first IV administration should occur in a clinical setting with emergency equipment available. ### How does Gonadorelin compare to HCG for TRT? Gonadorelin works upstream by stimulating the pituitary to release LH naturally, while HCG directly mimics LH at the testicular level. Gonadorelin preserves the entire HPG signaling cascade while HCG bypasses the pituitary entirely. Both can preserve testicular function, but through fundamentally different pharmacological mechanisms. ### Is Gonadorelin FDA approved? Yes. Gonadorelin has FDA-approved uses for evaluating hypothalamic-pituitary-gonadal axis function (the GnRH stimulation test) and for inducing ovulation in women with hypothalamic amenorrhea. Its use as a TRT adjunct for testicular preservation represents off-label but increasingly common clinical application. ## References 1. Hoffman AR, Crowley WF. "Induction of puberty in men by long-term pulsatile administration of low-dose gonadotropin-releasing hormone." *N Engl J Med*, 1982. PMID: 6813732. https://pubmed.ncbi.nlm.nih.gov/6813732/ 2. Kim HK, Kee SJ, Seo JY, et al.. "Gonadotropin-releasing hormone stimulation test for precocious puberty." *Korean J Lab Med*, 2011. PMID: 22016677. https://pubmed.ncbi.nlm.nih.gov/22016677/ 3. Sun Q, Li S, Zhang B, et al.. "Role of Gonadotropin-releasing Hormone Stimulation Test in Diagnosing Gonadotropin Deficiency in Both Males and Females with Delayed Puberty." *Chin Med J (Engl)*, 2015. PMID: 26365959. https://pubmed.ncbi.nlm.nih.gov/26365959/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Gonadorelin use outside of its FDA-approved indications is not sanctioned for medical practice. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/gonadorelin --- # HCG **Human Chorionic Gonadotropin (HCG)** Category: Hormonal > Glycoprotein Hormone for Hormonal Health Human chorionic gonadotropin (HCG) is a glycoprotein hormone composed of 237 amino acids with FDA-approved indications for cryptorchidism, hypogonadotropic hypogonadism, and ovulation induction. It exerts its primary effects by binding to the LH/HCG receptor on gonadal tissue, stimulating testosterone production in males and progesterone production in females. ## Key Facts - **Molecular weight:** ~36.7 kDa (protein core; ~37.9-39.5 kDa glycosylated intact hormone) (source: https://en.wikipedia.org/wiki/Human_chorionic_gonadotropin) - **Sequence length:** 237 (alpha subunit 92 + beta subunit 145) (source: https://www.drugs.com/monograph/choriogonadotropin-alfa.html) - **Primary target:** LH/hCG receptor (luteinizing hormone/choriogonadotropin receptor, GPCR) on Leydig cells and ovarian corpus luteum (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=dc604794-6dd6-43a7-85fa-2f04ed325c33) - **Mechanism class:** Gonadotropin / LH receptor agonist (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=dc604794-6dd6-43a7-85fa-2f04ed325c33) - **Half-life:** Recombinant (Ovidrel): terminal ~29 +/- 6 h SC, 26.5 +/- 2.5 h IV (initial ~4.5 +/- 0.5 h). Urinary (Pregnyl): biphasic ~11 h initial, ~23 h terminal (source: https://www.accessdata.fda.gov/drugsatfda_docs/label/2010/021149s020lbl.pdf) - **Route of administration:** Intramuscular (IM) or subcutaneous (SQ) injection (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=dc604794-6dd6-43a7-85fa-2f04ed325c33) - **Regulatory status:** FDA-approved: prepubertal cryptorchidism, hypogonadotropic hypogonadism (males), ovulation induction (females); recombinant Ovidrel approved 2000 (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=dc604794-6dd6-43a7-85fa-2f04ed325c33) - **CAS number:** 9002-61-3 (chorionic gonadotropin, general); 177073-44-8 (recombinant choriogonadotropin alfa) (source: https://www.drugs.com/monograph/choriogonadotropin-alfa.html) ## Overview Human chorionic gonadotropin (HCG) is a glycoprotein hormone composed of 237 amino acids, with a total molecular mass of approximately 36.7 kDa. It is a heterodimer consisting of a non-covalently bound alpha subunit (14.5 kDa) and a beta subunit (22.2 kDa). The alpha subunit is structurally shared with three other pituitary glycoprotein hormones: luteinizing hormone (LH), follicle-stimulating hormone (FSH), and thyroid-stimulating hormone (TSH). The beta subunit of HCG confers its biological specificity and provides the basis for its use in pregnancy testing, as it is distinct from the LH beta subunit at the C-terminal extension. HCG exerts its primary biological effects by binding to the LH/HCG receptor, a G protein-coupled receptor expressed on gonadal tissue. In males, this receptor is located on Leydig cells in the testes, where HCG binding stimulates the production of testosterone, the primary androgen responsible for secondary sexual characteristics, spermatogenesis support, and anabolic activity. In females, HCG binds to receptors on the corpus luteum, stimulating progesterone production and supporting the luteal phase during early pregnancy. HCG has well-established FDA-approved clinical indications. In males, it is approved for the treatment of prepubertal cryptorchidism (undescended testes) and hypogonadotropic hypogonadism. In females, it is approved for the induction of ovulation in women who fail to ovulate due to anovulatory conditions, and as a component of assisted reproductive technology protocols. In the context of androgen replacement therapy and post-cycle recovery from androgenic anabolic steroid use, HCG is used to maintain or restore endogenous testosterone production and testicular function. Exogenous testosterone suppresses LH secretion via negative feedback on the pituitary, leading to testicular atrophy and cessation of spermatogenesis over time. Periodic HCG administration bypasses the suppressed LH signal and directly stimulates Leydig cell testosterone production, preserving testicular size and function. ## Dosage Route: Intramuscular (IM) or subcutaneous (SQ) injection ### Schedule | Period | Dose | | --- | --- | | Cryptorchidism (children 4-9 years) | 4,500 IU 3x weekly for 4-6 weeks | | Hypogonadotropic hypogonadism (males) | 500-1,000 IU 3x weekly IM for 3 weeks, then 2x/week x 3 weeks | | Ovulation induction (females) | 5,000-10,000 IU single dose after follicle maturation | | TRT adjunct / testicular maintenance | 250-500 IU every 3-4 days SQ | | Post-cycle recovery | 500-1,000 IU daily or every other day SQ for 10-14 days | ### Reconstitution - Vial size: Varies by supplier - Water volume: Per vial labeling - Concentration: Per vial labeling - Per unit: Varies by reconstitution volume ### Tips - HCG is supplied as a lyophilized powder and requires reconstitution with bacteriostatic water for injection - Refrigerate reconstituted solution and use within 30 to 60 days depending on concentration and storage conditions - Dosing varies considerably by indication; clinical doses for fertility are substantially higher than doses for testicular maintenance - Monitor with laboratory testing (total testosterone, LH, FSH, estradiol as relevant) - HCG can aromatize to estrogen via peripheral aromatase enzymes, particularly at higher doses; managing estrogen with an aromatase inhibitor may be necessary ## Side Effects ### Common - Injection site pain and bruising, particularly with intramuscular administration - Headache, fatigue, and irritability - Water retention associated with HCG-stimulated testosterone and estrogen production - Gynecomastia due to elevated estradiol from aromatization - Mood fluctuations associated with hormonal shifts - Acne, particularly during post-cycle or high-dose protocols ### Severe / Theoretical Risks - **Ovarian hyperstimulation syndrome (OHSS)**: A potentially life-threatening condition in women characterized by massively enlarged ovaries, fluid shifts into the abdominal and pleural cavities, hemoconcentration, and thromboembolism risk. Risk is highest in women with polycystic ovarian morphology. - **Multiple gestation**: Use of HCG in ovulation induction protocols carries a risk of multiple embryo implantation and multiple pregnancy. - **Thromboembolism**: Elevated sex hormones carry prothrombotic risk, particularly at high doses. - **Leydig cell desensitization**: Chronic LH/HCG receptor overstimulation from very high or continuous HCG use can paradoxically reduce Leydig cell responsiveness. - **Acceleration of androgen-sensitive malignancies**: HCG-stimulated testosterone may worsen prostate cancer and other androgen-sensitive conditions. ### Contraindications - Androgen-sensitive malignancies (prostate cancer, testicular cancer) - Primary testicular failure (where Leydig cells cannot respond to LH/HCG signaling) - Precocious puberty in pediatric patients - Pregnancy in women (except in specific assisted reproduction contexts under specialist supervision) - Hypersensitivity to HCG or formulation components - Ovarian cysts or enlargement not related to polycystic ovarian syndrome - Uncontrolled thyroid or adrenal disorders ## FAQ ### What is HCG and what is it used for? Human Chorionic Gonadotropin (HCG) is a 237-amino acid glycoprotein hormone with FDA-approved indications for cryptorchidism, hypogonadotropic hypogonadism, and ovulation induction. It binds the LH receptor to stimulate testosterone production in men and progesterone production in women. ### How does HCG help during testosterone replacement therapy? Exogenous testosterone suppresses LH, causing testicular atrophy and cessation of spermatogenesis. HCG bypasses the suppressed pituitary signal and directly stimulates Leydig cell testosterone production, preserving testicular size and function. Typical TRT adjunct doses are 250 to 500 IU every 3 to 4 days subcutaneously. ### What is the HCG dosage for post-cycle therapy? Post-cycle recovery protocols typically use 500 to 1,000 IU daily or every other day subcutaneously for 10 to 14 days. For TRT maintenance, 250 to 500 IU every 3 to 4 days is standard. Clinical fertility doses are substantially higher at 5,000 to 10,000 IU and require specialist supervision. ### Does HCG cause estrogen side effects? Yes. HCG can aromatize to estrogen via peripheral aromatase enzymes, particularly at higher doses. This may cause gynecomastia, water retention, and mood fluctuations. Managing estrogen with an aromatase inhibitor may be necessary, especially during high-dose protocols or in individuals prone to aromatization. ### What are HCG side effects? Common side effects include injection site pain, headache, water retention, gynecomastia from elevated estradiol, mood fluctuations, and acne. Serious risks include ovarian hyperstimulation syndrome in women, thromboembolism from elevated sex hormones, and Leydig cell desensitization from chronic high-dose use. ### Is HCG FDA approved? Yes. HCG is FDA-approved for prepubertal cryptorchidism, hypogonadotropic hypogonadism in males, and ovulation induction in females. Its use as a TRT adjunct or for post-cycle therapy from anabolic steroid use represents off-label application that is common but not FDA-reviewed for those purposes. ## References 1. Coviello AD, Matsumoto AM, Bremner WJ, et al.. "Low-dose human chorionic gonadotropin maintains intratesticular testosterone [^1] in normal men with testosterone-induced gonadotropin suppression." *J Clin Endocrinol Metab*, 2005. PMID: 15713727. https://pubmed.ncbi.nlm.nih.gov/15713727/ 2. Hsieh TC, Pastuszak AW, Hwang K, et al.. "preserves spermatogenesis in men undergoing testosterone replacement therapy [^2]." *J Urol*, 2013. PMID: 23260550. https://pubmed.ncbi.nlm.nih.gov/23260550/ 3. Fink J, Matsumoto M, Tamura Y. "Human chorionic gonadotropin treatment: a viable option for management of secondary hypogonadism and male infertility." *Expert Rev Endocrinol Metab*, 2021. PMID: 33345656. https://pubmed.ncbi.nlm.nih.gov/33345656/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. HCG is FDA-approved for specific indications; use outside of those approved indications is off-label. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/hcg --- # Triptorelin **Triptorelin (GnRH Analog)** Category: Hormonal > Synthetic GnRH Analog for Hormonal Health Triptorelin is a synthetic decapeptide analog of gonadotropin-releasing hormone (GnRH) with FDA approval for palliative treatment of advanced prostate cancer. It produces a biphasic response: an initial LH/FSH surge followed by pituitary desensitization and testosterone suppression. At low investigational doses (~100 mcg), it is studied for post-cycle therapy to leverage only the initial flare phase for HPG axis recovery. ## Key Facts - **Molecular weight:** 1311.4 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/25074470) - **Molecular formula:** C64H82N18O13 (source: https://pubchem.ncbi.nlm.nih.gov/compound/25074470) - **Sequence length:** 10 amino acids (decapeptide; pGlu-His-Trp-Ser-Tyr-D-Trp-Leu-Arg-Pro-Gly-NH2) (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/25074470/JSON?heading=Depositor-Supplied+Synonyms) - **Primary target:** GnRH receptor (pituitary gonadotropes) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=b1b84d62-a369-a4b7-5c41-dd1f553a18f3) - **Mechanism class:** GnRH receptor agonist (gonadotropin-releasing hormone agonist) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=b1b84d62-a369-a4b7-5c41-dd1f553a18f3) - **Half-life:** ~6 min, ~45 min, and ~3 hours (three-compartment model, after IV bolus in healthy men) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=b1b84d62-a369-a4b7-5c41-dd1f553a18f3) - **Route of administration:** Intramuscular (depot); subcutaneous in investigational PCT use (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=b1b84d62-a369-a4b7-5c41-dd1f553a18f3) - **Regulatory status:** FDA-approved (Trelstar, triptorelin pamoate) for treatment of advanced prostate cancer; Initial U.S. Approval 2000 (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=b1b84d62-a369-a4b7-5c41-dd1f553a18f3) - **CAS number:** 57773-63-4 (source: https://pubchem.ncbi.nlm.nih.gov/compound/25074470) ## Overview Triptorelin is a synthetic decapeptide analog of gonadotropin-releasing hormone (GnRH), a hypothalamic hormone responsible for stimulating the pituitary gland to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Under physiological conditions, GnRH is released in pulses; triptorelin's continuous or depot administration disrupts this pulsatile pattern and produces a paradoxical suppression of gonadotropin secretion after an initial stimulatory flare. Clinically, triptorelin is FDA-approved under the brand name Trelstar for the palliative treatment of advanced prostate cancer, where it reduces testosterone to castrate levels to slow tumor progression. It is also used off-label in the treatment of precocious puberty, endometriosis, uterine fibroids, and as part of in vitro fertilization protocols. Within research and sports performance circles, triptorelin has attracted attention as a post-cycle therapy (PCT) agent for restoring hypothalamic-pituitary-gonadal (HPG) axis function following exogenous androgen use. The biphasic pharmacological response is central to understanding both its clinical utility and its PCT application. Within the first one to two weeks of a single low-dose injection, triptorelin causes a transient surge in LH and FSH (the flare effect), which transiently elevates testosterone. Following this initial stimulation, continuous receptor occupancy desensitizes pituitary GnRH receptors, leading to suppression. A single low dose (100 mcg) in the PCT context is intended to leverage only the flare phase to restart endogenous LH and testosterone production without crossing into suppression territory. At depot doses used in oncology (3.75 mg, 11.25 mg, or 22.5 mg delivered monthly, quarterly, or semi-annually), triptorelin reliably suppresses testosterone to castrate range. At the micro-doses explored in PCT research (around 100 mcg), the intent is the opposite: to transiently stimulate LH and FSH secretion and accelerate HPG axis recovery. The margin between these two outcomes is narrow and requires precise dosing. ## Dosage Route: Intramuscular (depot) or subcutaneous (investigational PCT use) ### Schedule | Period | Dose | | --- | --- | | Trelstar 3.75 mg (oncology) | 3.75 mg IM every 4 weeks | | Trelstar 11.25 mg (oncology) | 11.25 mg IM every 12 weeks | | Trelstar 22.5 mg (oncology) | 22.5 mg IM every 24 weeks | | Investigational PCT (single administration) | 100 mcg subcutaneous; may repeat after 30 days if testosterone has not returned to reference range | ### Reconstitution - Vial size: Varies by supplier - Water volume: Bacteriostatic water per vial labeling - Concentration: Per vial labeling - Per unit: Varies by reconstitution volume ### Tips - Triptorelin acetate for research use is supplied as lyophilized powder; reconstitute with bacteriostatic water to desired concentration - Maintain cold chain storage at 2-8 degrees Celsius - Do not exceed 100 mcg in a single PCT administration - Administer after cessation of exogenous testosterone or anabolic steroids in PCT context - The margin between PCT-stimulatory and suppressive dosing is narrow; precise dosing is critical ## Side Effects ### Common - Hot flashes (most common at castrate-range dosing) - Decreased libido and erectile dysfunction (at suppressive doses) - Gynecomastia (from estrogen:androgen imbalance during flare or suppression) - Injection site pain or swelling - Headache - Fatigue - Testicular atrophy (with prolonged use at suppressive doses) ### Severe / Theoretical Risks - **Severe hypersensitivity or anaphylaxis**: Rare but reported hypersensitivity reactions to GnRH agonist class compounds. - **Tumor flare in prostate cancer**: Testosterone surge in first 1-2 weeks may transiently worsen symptoms; use antiandrogens concurrently for 2-4 weeks at initiation. - **Pituitary apoplexy**: Rare; reported with GnRH agonist class. - **Spinal cord compression**: In patients with vertebral metastases from tumor flare, spinal cord compression can occur. - **Prolonged hypogonadism**: Overdose can cause persistent HPG suppression rather than recovery, resulting in prolonged hypogonadism. - **Bone density loss**: Osteoporosis risk with long-term castrate-range dosing. ### Contraindications - Women who are pregnant or may become pregnant (triptorelin can harm the fetus) - Hypersensitivity to GnRH, GnRH agonist analogs, or any component of the formulation - Undiagnosed vaginal bleeding - Use as PCT in women (not appropriate; designed for male HPG axis recovery) - Pre-existing severe osteoporosis (long-term use contraindicated without bone protection) ## FAQ ### What is Triptorelin and what is it used for? Triptorelin is a synthetic GnRH analog FDA-approved as Trelstar for palliative treatment of advanced prostate cancer. It produces a biphasic response: an initial LH/FSH surge (flare) followed by pituitary desensitization and testosterone suppression. At low doses around 100 mcg, it is studied for post-cycle therapy. ### How does Triptorelin work for post-cycle therapy? A single low dose of approximately 100 mcg leverages only the initial flare phase to restart endogenous LH and testosterone production after anabolic steroid cessation. This transient surge stimulates the HPG axis without crossing into the suppressive territory that occurs with sustained or depot-level dosing. ### What is the correct Triptorelin PCT dosage? The investigational PCT dose is 100 mcg subcutaneous as a single administration. A repeat dose may be given after 30 days if testosterone has not returned to reference range. The margin between PCT-stimulatory and suppressive dosing is narrow, so exceeding 100 mcg risks prolonged hypogonadism. ### What happens if you take too much Triptorelin? Overdosing causes persistent HPG suppression rather than recovery, resulting in prolonged hypogonadism with testosterone dropping to castrate levels. At depot doses used in oncology (3.75 to 22.5 mg), triptorelin reliably suppresses testosterone for weeks to months. Precise micro-dosing is critical for PCT use. ### What are Triptorelin side effects? At suppressive oncology doses, common effects include hot flashes, decreased libido, gynecomastia, testicular atrophy, and bone density loss. At micro-PCT doses, side effects are typically limited to injection site reactions and transient headache. The initial testosterone surge may temporarily worsen symptoms in prostate cancer patients. ### Is Triptorelin FDA approved? Triptorelin is FDA-approved under the brand name Trelstar only for palliative treatment of advanced prostate cancer at depot doses of 3.75, 11.25, or 22.5 mg. Its use for post-cycle therapy at micro-doses around 100 mcg is entirely investigational and off-label with limited published clinical support. ## References 1. Heyns CF, Simonin MP, Grosgurin P, et al.. "Comparative efficacy of triptorelin pamoate and leuprolide acetate in men with advanced prostate cancer." *BJU Int*, 2003. PMID: 12887472. https://pubmed.ncbi.nlm.nih.gov/12887472/ 2. Carel JC, Roger M, Ispas S, et al.. "Final height after long-term treatment with triptorelin slow release for central precocious puberty: importance of statural growth after interruption of treatment." *J Clin Endocrinol Metab*, 1999. PMID: 10372696. https://pubmed.ncbi.nlm.nih.gov/10372696/ 3. Klein KO, Freire A, Gryngarten MG, et al.. "Efficacy and safety of triptorelin 6-month formulation in patients with central precocious puberty." *J Pediatr Endocrinol Metab*, 2016. PMID: 26887034. https://pubmed.ncbi.nlm.nih.gov/26887034/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Triptorelin is FDA-approved only for palliative treatment of advanced prostate cancer; all other uses described here are investigational or off-label. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/triptorelin --- # Cetrorelix **Cetrorelix** Category: Hormonal > GnRH Antagonist for Hormonal Regulation Cetrorelix is a synthetic decapeptide GnRH receptor antagonist that produces immediate, dose-dependent suppression of LH and FSH without an initial hormonal flare. Approved for use in assisted reproductive technology, it is also investigated in hormone-sensitive conditions including prostate cancer, endometriosis, and uterine fibroids. ## Key Facts - **Molecular weight:** 1431.0 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/25074887) - **Molecular formula:** C70H92ClN17O14 (source: https://pubchem.ncbi.nlm.nih.gov/compound/25074887) - **Sequence length:** 10 (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=aca7768e-28a7-4027-b1d8-e66247665f79&type=display) - **Primary target:** Gonadotropin-releasing hormone (GnRH) receptor (pituitary) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=aca7768e-28a7-4027-b1d8-e66247665f79&type=display) - **Mechanism class:** GnRH receptor antagonist (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=aca7768e-28a7-4027-b1d8-e66247665f79&type=display) - **Half-life:** 5.0 h (0.25 mg SC single dose); 62.8 h (3 mg SC single/depot dose) - dose-dependent (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=aca7768e-28a7-4027-b1d8-e66247665f79&type=display) - **Route of administration:** Subcutaneous injection (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=aca7768e-28a7-4027-b1d8-e66247665f79&type=display) - **Regulatory status:** FDA-approved (2000) as Cetrotide for inhibition of premature LH surges in women undergoing controlled ovarian stimulation (ART) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=aca7768e-28a7-4027-b1d8-e66247665f79&type=display) - **CAS number:** 120287-85-6 (source: https://pubchem.ncbi.nlm.nih.gov/compound/25074887) ## Overview Cetrorelix is a synthetic decapeptide that acts as a competitive antagonist at gonadotropin-releasing hormone (GnRH) receptors on pituitary cells. Unlike GnRH agonists, which cause an initial hormonal surge before suppression, cetrorelix produces immediate, dose-dependent suppression of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) without any initial flare effect. This makes it particularly valuable in reproductive medicine, where preventing a premature LH surge during controlled ovarian stimulation is critical to assisted reproduction outcomes. The peptide was developed as a third-generation GnRH antagonist, synthetically modified to overcome the histamine-releasing properties associated with earlier GnRH antagonists. Its competitive binding to pituitary GnRH receptors is fully reversible, and normal gonadotropin secretion resumes promptly once the drug clears the system. This reversibility is a meaningful clinical advantage over GnRH agonist protocols, which can suppress pituitary function for weeks after discontinuation. Clinically, cetrorelix has been studied in large multicenter Phase IIIb trials evaluating both multiple-dose (0.25 mg/day) and single-dose (3 mg) protocols in the context of in vitro fertilization. Both approaches achieved suppression of premature LH surges in over 90% of patients and produced comparable pregnancy and live birth rates to long GnRH agonist protocols, while requiring shorter durations of gonadotropin stimulation and lower total gonadotropin doses. The incidence of ovarian hyperstimulation syndrome (OHSS) was also reduced compared to agonist-based protocols. Beyond reproductive medicine, cetrorelix has been investigated in hormone-sensitive conditions including prostate cancer, breast cancer in pre- and perimenopausal women, endometriosis, uterine fibroids, and endometrial thinning. These applications exploit the peptide's ability to suppress circulating sex hormones rapidly. While FDA approval is specifically for use in ART (assisted reproductive technology), ongoing research continues to explore expanded indications in hormone-dependent disease states. ## Dosage Route: Subcutaneous injection ### Schedule | Period | Dose | | --- | --- | | Multiple-dose protocol | 0.25 mg once daily (approximately 24-hour suppression per dose) | | Single-dose protocol | 3 mg one injection (depot effect; up to 96-hour suppression) | ### Reconstitution - Vial size: 0.25 mg or 3 mg - Water volume: 1 mL (0.25 mg vial); 3 mL (3 mg vial) - Concentration: 0.25 mg/mL or 1 mg/mL - Per unit: Use immediately after reconstitution; do not store reconstituted solution ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 0.25 mg | 1 mL | Full 0.25 mg vial | | 3 mg | 3 mL | Full 3 mg vial; depot release over up to 96 hours | ### Tips - Reconstitute with the sterile water provided in the kit - Use immediately after reconstitution - In ART protocols, either approach is typically combined with gonadotropin stimulation (FSH or hMG) - Terminate cetrorelix with HCG trigger administration for oocyte maturation - The single 3 mg dose forms a subcutaneous depot providing sustained LH suppression for up to four days - The multiple-dose 0.25 mg protocol begins on stimulation day 5 or 6 and continues through HCG administration ## Side Effects ### Common - Injection site reactions: redness, bruising, or mild swelling - Nausea - Headache - Ovarian hyperstimulation syndrome (OHSS) in the context of ART, though at lower rates than with GnRH agonist protocols ### Severe / Theoretical Risks - **Severe OHSS**: Rare but serious: abdominal pain, bloating, difficulty breathing, and reduced urination. Requires prompt medical evaluation. - **Hypersensitivity reactions**: Rash and urticaria have been reported. Anaphylaxis is rare but documented in the GnRH antagonist class. - **Fetal harm**: Cetrorelix is contraindicated during pregnancy. It must not be used once pregnancy is confirmed. ### Contraindications - Pregnancy or breastfeeding - Hypersensitivity to cetrorelix, mannitol, GnRH, or other GnRH analogs - Severe renal impairment - Postmenopausal status (in the reproductive indication) - Pediatric patients ## FAQ ### What is Cetrorelix and what is it used for? Cetrorelix is a synthetic decapeptide GnRH receptor antagonist approved for use in assisted reproductive technology. It immediately suppresses LH and FSH without an initial hormonal flare, preventing premature ovulation during controlled ovarian stimulation for IVF. It is also investigated for hormone-sensitive conditions. ### How does Cetrorelix differ from GnRH agonists like Lupron? Unlike GnRH agonists that cause an initial hormonal surge before suppression, cetrorelix produces immediate LH and FSH suppression with no flare effect. Its competitive binding is fully reversible, and normal gonadotropin secretion resumes promptly once the drug clears, unlike agonists which can suppress for weeks. ### What are the two Cetrorelix dosing protocols? The multiple-dose protocol uses 0.25 mg once daily starting on stimulation day 5 or 6 through HCG trigger administration. The single-dose protocol gives one 3 mg injection that forms a subcutaneous depot providing sustained LH suppression for up to four days. Both achieve over 90% suppression rates. ### What are Cetrorelix side effects? Common side effects include injection site reactions, nausea, headache, and ovarian hyperstimulation syndrome at lower rates than GnRH agonist protocols. Serious risks include severe OHSS with abdominal pain and breathing difficulty, rare hypersensitivity reactions, and fetal harm if used during confirmed pregnancy. ### Can Cetrorelix be used for conditions other than IVF? Research has investigated cetrorelix for prostate cancer, breast cancer in premenopausal women, endometriosis, uterine fibroids, and endometrial thinning. These applications exploit its ability to suppress circulating sex hormones rapidly. However, FDA approval is specifically limited to assisted reproductive technology. ### Is Cetrorelix better than Ganirelix? Both are third-generation GnRH antagonists with similar efficacy in preventing premature LH surges during IVF. Clinical trials show comparable pregnancy rates and live birth rates between them. The choice typically depends on physician preference, institutional protocols, and individual patient response rather than clear superiority. ## References 1. Felberbaum RE, Reissmann T, Kupker W, et al.. "Ovarian stimulation for assisted reproduction with HMG and concomitant midcycle administration of the GnRH antagonist cetrorelix according to the multiple dose protocol: a prospective uncontrolled phase III study." *Hum Reprod*, 2000. PMID: 10783344. https://pubmed.ncbi.nlm.nih.gov/10783344/ 2. Olivennes F, Fanchin R, Bouchard P, et al.. "The use of a GnRH antagonist (Cetrorelix) in a single dose protocol in IVF-embryo transfer: a dose finding study of 3 versus 2 mg." *Hum Reprod*, 1998. PMID: 9806259. https://pubmed.ncbi.nlm.nih.gov/9806259/ 3. Xavier P, Gamboa C, Almeida JP, et al.. "A randomised study of GnRH antagonist (cetrorelix) versus agonist (busereline) for controlled ovarian stimulation: effect on safety and efficacy." *Eur J Obstet Gynecol Reprod Biol*, 2005. PMID: 15925049. https://pubmed.ncbi.nlm.nih.gov/15925049/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Cetrorelix has not been approved by the FDA for any medical condition beyond controlled ovarian stimulation in ART. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/cetrorelix --- # Degarelix **Degarelix** Category: Hormonal > GnRH Antagonist for Androgen Deprivation Therapy Degarelix is a synthetic peptide GnRH receptor antagonist approved for androgen deprivation therapy (ADT) in advanced prostate cancer. It produces rapid, sustained testosterone suppression to castrate levels within three days of the loading dose, without the testosterone flare associated with GnRH agonists. ## Key Facts - **Molecular weight:** 1632.3 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/16136245/property/MolecularFormula,MolecularWeight,IUPACName/JSON) - **Molecular formula:** C82H103ClN18O16 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/16136245/property/MolecularFormula,MolecularWeight,IUPACName/JSON) - **Sequence length:** 10 (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=ab11dd8a-0fd9-4013-89ab-e114557c7e4b) - **Primary target:** Pituitary GnRH (gonadotropin-releasing hormone) receptor (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=ab11dd8a-0fd9-4013-89ab-e114557c7e4b) - **Mechanism class:** GnRH receptor antagonist (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=ab11dd8a-0fd9-4013-89ab-e114557c7e4b) - **Half-life:** ~53 days (median terminal half-life after subcutaneous 240 mg loading dose) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=ab11dd8a-0fd9-4013-89ab-e114557c7e4b) - **Route of administration:** Subcutaneous injection (abdominal region only); no oral formulation (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=ab11dd8a-0fd9-4013-89ab-e114557c7e4b) - **Regulatory status:** FDA-approved (2008) for treatment of patients with advanced prostate cancer; marketed as Firmagon (Ferring Pharmaceuticals) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=ab11dd8a-0fd9-4013-89ab-e114557c7e4b) - **CAS number:** 214766-78-6 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16136245) ## Overview Degarelix is a synthetic peptide GnRH (gonadotropin-releasing hormone) receptor antagonist approved for androgen deprivation therapy (ADT) in advanced prostate cancer. It consists of a modified decapeptide sequence that binds reversibly but with high affinity to pituitary GnRH receptors, immediately blocking the gonadotropin cascade that drives testicular testosterone synthesis. The result is a rapid, sustained reduction in serum LH, FSH, and testosterone without the initial hormonal surge that characterizes GnRH agonist therapy. This absence of a testosterone flare distinguishes degarelix from GnRH agonists such as leuprolide. With agonist-based ADT, the initial receptor stimulation triggers a transient rise in testosterone (the 'flare') that can temporarily worsen bone pain, urinary obstruction, or spinal cord compression in men with metastatic disease. Because degarelix acts as a pure competitive antagonist from first dosing, testosterone suppression begins within days rather than weeks, and no flare occurs. In a pivotal Phase III trial of 610 patients, degarelix achieved testosterone levels at or below 0.5 ng/mL within three days in over 96% of subjects, compared to approximately three weeks required for leuprolide to reach castrate levels. Degarelix was synthetically engineered to overcome the histamine-releasing properties that limited earlier GnRH antagonists such as abarelix. Its structural modifications result in very weak histamine-releasing activity, substantially reducing the risk of immediate hypersensitivity reactions that made earlier antagonists difficult to use in clinical practice. Upon subcutaneous administration, degarelix forms a gel-like depot at the injection site that releases the drug in a first-order manner, providing sustained pharmacological activity between monthly doses. Beyond testosterone suppression, early data suggest that degarelix may offer cardiovascular advantages over GnRH agonists. Observational and retrospective analyses have found associations between degarelix use and lower rates of major adverse cardiovascular events compared to leuprolide, though prospective randomized data are still maturing. The PSA decline rate is also more rapid with degarelix, which may have prognostic relevance for monitoring treatment response. ## Dosage Route: Subcutaneous injection, abdominal region only; not available as oral formulation ### Schedule | Period | Dose | | --- | --- | | Loading dose (Day 1) | 240 mg (two 120 mg subcutaneous injections) | | Maintenance dose | 80 mg subcutaneous injection every 28 days | ### Reconstitution - Vial size: 120 mg (loading) or 80 mg (maintenance) - Water volume: 3 mL sterile water (120 mg vial); 4.2 mL sterile water (80 mg vial) - Concentration: 40 mg/mL (loading); 20 mg/mL (maintenance) - Per unit: Both loading injections must be given on the same day in different abdominal areas ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 120 mg (x2 loading) | 3 mL per vial | Two separate injections, different sites | | 80 mg (maintenance) | 4 mL | Single monthly injection | ### Tips - Administer only by subcutaneous injection in the abdominal region - Loading dose: both 120 mg injections must be given on Day 1 in different abdominal areas - Maintenance: one 80 mg injection every 28 days - Monitor serum testosterone prior to therapy and periodically during treatment - Confirm maintenance of castrate testosterone levels below 50 ng/dL (0.5 ng/mL) - Monitor PSA as a surrogate marker of disease response ## Side Effects ### Common - Injection site reactions: pain, erythema, swelling, and induration (approximately 40% of patients; typically mild to moderate and transient) - Hot flashes (flushing): the most common systemic effect, reported in 25-30% of patients - Weight gain - Fatigue - Chills (approximately 4% of patients) - Elevated liver enzymes (transaminases): monitor LFTs periodically ### Severe / Theoretical Risks - **QT interval prolongation**: Androgen deprivation in general is associated with QT prolongation. Use with caution in patients on QT-prolonging drugs or with baseline cardiac risk factors. - **Bone mineral density loss**: Chronic testosterone suppression leads to accelerated osteoporosis. Baseline and periodic bone density monitoring is recommended for patients on long-term ADT. - **Metabolic effects**: Insulin resistance, dyslipidemia, and increased cardiovascular risk are associated with long-term androgen deprivation therapy. - **Depression and cognitive effects**: Testosterone suppression can exacerbate depressive symptoms and may affect cognitive function. Monitor mental health during treatment. ### Contraindications - Known hypersensitivity to degarelix or any component of the formulation - Use in women (not indicated; GnRH antagonists cause fetal harm) - Pediatric use (not studied) ## FAQ ### What is Degarelix and how does it work? Degarelix is a synthetic peptide GnRH receptor antagonist approved for androgen deprivation therapy in advanced prostate cancer. It immediately blocks pituitary GnRH receptors to suppress LH, FSH, and testosterone production. Unlike GnRH agonists, it achieves castrate testosterone levels within three days without any initial hormonal flare. ### Why does Degarelix avoid the testosterone flare? Degarelix is a pure competitive antagonist that blocks GnRH receptors from first dosing. GnRH agonists like leuprolide initially stimulate the receptor before desensitizing it, causing a temporary testosterone surge that can worsen cancer symptoms. Degarelix eliminates this dangerous 1 to 2 week flare period entirely. ### How is Degarelix dosed? The loading dose is 240 mg on Day 1, given as two separate 120 mg subcutaneous injections in different abdominal areas. Monthly maintenance is 80 mg subcutaneously every 28 days. Both injections form gel-like depots that release the drug in a sustained manner between doses. ### What are Degarelix side effects? Common effects include injection site reactions (approximately 40% of patients), hot flashes (25 to 30%), weight gain, fatigue, and elevated liver enzymes. Long-term androgen deprivation risks include bone density loss, insulin resistance, QT prolongation, depression, and cognitive effects from chronic testosterone suppression. ### Does Degarelix have cardiovascular advantages over Lupron? Early data suggest degarelix may offer cardiovascular advantages over GnRH agonists. Observational analyses found associations between degarelix use and lower rates of major adverse cardiovascular events compared to leuprolide. Prospective randomized data are still maturing, but this potential benefit is clinically significant. ### Is Degarelix used for anything besides prostate cancer? Degarelix is FDA-approved only for advanced prostate cancer. Research has explored its use in other hormone-sensitive conditions, but these applications remain investigational. Its rapid, flare-free testosterone suppression makes it uniquely valuable when avoiding initial hormone surges is medically critical. ## References 1. Klotz L, Boccon-Gibod L, Shore ND, et al.. "The efficacy and safety of degarelix: a 12-month, comparative, randomized, open-label, parallel-group phase III study in patients with prostate cancer." *BJU Int*, 2008. PMID: 19035858. https://pubmed.ncbi.nlm.nih.gov/19035858/ 2. Van Poppel H, Nilsson S. "Evaluation of degarelix in the management of prostate cancer." *Cancer Manag Res*, 2010. PMID: 21188095. https://pubmed.ncbi.nlm.nih.gov/21188095/ 3. Smith MR, Klotz L, Persson BE, et al.. "Cardiovascular safety of degarelix: results from a 12-month, comparative, randomized, open label, parallel group phase III trial in patients with prostate cancer." *J Urol*, 2010. PMID: 20952020. https://pubmed.ncbi.nlm.nih.gov/20952020/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Degarelix has not been approved by the FDA for any medical condition other than the treatment of advanced prostate cancer. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/degarelix --- # Octreotide **Octreotide (Synthetic Somatostatin Analog)** Category: Hormonal > Synthetic Somatostatin Analog for Hormonal Health Octreotide is a synthetic octapeptide analog of somatostatin engineered to achieve a therapeutically practical half-life (1.7 hours immediate-release; weeks for depot formulation). FDA-approved for acromegaly, carcinoid syndrome, and VIPomas, it broadly inhibits growth hormone, glucagon, insulin, and multiple gut hormones by binding somatostatin receptors SSTR2, SSTR3, and SSTR5. ## Key Facts - **Molecular weight:** 1019.2 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/448601/property/MolecularFormula,MolecularWeight,IUPACName,CanonicalSMILES/JSON) - **Molecular formula:** C49H66N10O10S2 (source: https://pubchem.ncbi.nlm.nih.gov/compound/448601) - **Sequence length:** 8 amino acids (cyclic octapeptide) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=d0b7fe9e-7000-4b79-ba3b-291ce92c14f9) - **Primary target:** Somatostatin receptor subtype 2 (SSTR2); moderate affinity SSTR3 and SSTR5 (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC9944328/) - **Mechanism class:** Somatostatin analog (somatostatin receptor agonist) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=d0b7fe9e-7000-4b79-ba3b-291ce92c14f9) - **Half-life:** 1.7 hours (immediate-release subcutaneous); reported 1.7 to 1.9 h in PK studies vs 1 to 3 min for natural somatostatin (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=d0b7fe9e-7000-4b79-ba3b-291ce92c14f9) - **Route of administration:** Subcutaneous injection (immediate-release, Sandostatin) or gluteal intramuscular depot injection (Sandostatin LAR Depot, every 4 weeks) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=d0b7fe9e-7000-4b79-ba3b-291ce92c14f9) - **Regulatory status:** FDA-approved (Sandostatin, octreotide acetate); Initial U.S. Approval 1988. Indications: acromegaly, severe diarrhea/flushing from metastatic carcinoid tumors, and profuse watery diarrhea from VIP-secreting tumors (VIPomas) (source: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=d0b7fe9e-7000-4b79-ba3b-291ce92c14f9) - **CAS number:** 83150-76-9 (source: https://pubchem.ncbi.nlm.nih.gov/compound/448601) ## Overview Octreotide is a synthetic octapeptide analog of somatostatin, the endogenous hypothalamic hormone that broadly inhibits the secretion of multiple other hormones throughout the body. The natural somatostatin molecule has a half-life of only 1-3 minutes in circulation, making it impractical for therapeutic use. Octreotide was engineered to be pharmacologically equivalent to somatostatin while achieving a half-life of approximately 1.7 hours (immediate-release) or weeks (depot formulation), enabling effective hormonal management in clinical settings. Octreotide binds with high affinity to somatostatin receptor subtype 2 (SSTR2) and with lesser affinity to SSTR3 and SSTR5. This receptor binding profile closely mirrors natural somatostatin activity and produces inhibition of a wide range of secretory hormones: growth hormone (GH), glucagon, insulin, gastrin, cholecystokinin, secretin, vasoactive intestinal peptide (VIP), thyroid-stimulating hormone (TSH), and pancreatic polypeptide. It also reduces intestinal fluid secretion, slows gastrointestinal motility, and inhibits gallbladder contraction. FDA-approved indications include acromegaly (excess GH secretion from a pituitary adenoma), carcinoid syndrome associated with metastatic carcinoid tumors, and symptoms from vasoactive intestinal peptide-secreting tumors (VIPomas). In acromegaly, octreotide suppresses GH secretion and reduces circulating insulin-like growth factor-1 (IGF-1) levels. Long-term treatment can stabilize and sometimes reduce pituitary tumor volume. Beyond approved uses, octreotide is investigated in off-label contexts including prevention of post-operative pancreatic complications, management of gastrointestinal bleeding from portal hypertension, treatment of dumping syndrome, and as a component of peptide receptor radionuclide therapy (PRRT) protocols for neuroendocrine tumors. It has the longest-established efficacy and safety profile within the somatostatin analog class. ## Dosage Route: Subcutaneous injection (immediate-release) or intramuscular depot injection ### Schedule | Period | Dose | | --- | --- | | Acromegaly (starting) | 50 mcg three times daily (TID) subcutaneous; titrate to 100-250 mcg TID over 2-4 weeks | | Carcinoid/VIPoma | 100-600 mcg/day in 2-4 divided doses; 150 mcg TID median maintenance | | Maximum reported (divided doses) | Up to 1,500 mcg/24 hours with monitoring | | Sandostatin LAR depot 10 mg | 10 mg IM every 28 days | | Sandostatin LAR depot 20 mg | 20 mg IM every 28 days | | Sandostatin LAR depot 30 mg | 30 mg IM every 28 days | ### Reconstitution - Vial size: Pre-filled solutions available at 50 mcg/mL, 100 mcg/mL, and 500 mcg/mL - Water volume: No reconstitution required for pre-filled immediate-release formulations - Concentration: 50, 100, or 500 mcg/mL (immediate-release) - Per unit: Dose determined by concentration and injection volume ### Tips - Warm immediate-release solution to room temperature before injection to reduce discomfort - Inject subcutaneously; rotate sites to minimize lipodystrophy - The depot formulation must be administered by a healthcare professional into the gluteal muscle - Avoid inadvertent IV or subcutaneous administration of the depot suspension - Establish clinical response and tolerability with immediate-release before transitioning to depot formulation ## Side Effects ### Common - Nausea (most common, particularly at initiation) - Diarrhea or loose stools - Abdominal cramping and flatulence - Constipation (with longer-term use) - Injection site pain, redness, or swelling - Headache - Dizziness - Fatigue ### Severe / Theoretical Risks - **Gallstones (cholelithiasis)**: Octreotide reduces gallbladder contractility, leading to bile stasis and stone formation. Prevalence increases significantly with chronic use. Monitor with ultrasound periodically. - **Hypoglycemia or hyperglycemia**: Octreotide suppresses both insulin and glucagon; the net glycemic effect is variable and requires monitoring, particularly in diabetic patients. - **Bradycardia and conduction abnormalities**: QT prolongation risk; monitor with ECG in at-risk patients. - **Hypothyroidism**: Risk increases with long-term use due to TSH suppression. - **Pancreatitis**: Rare, reported with somatostatin analog class. - **Cardiac valve disorders**: Documented more prominently with lanreotide; data for octreotide limited but warrants monitoring with long-term use. ### Contraindications - Known hypersensitivity to octreotide or any component of the formulation - Caution with insulin-dependent diabetes mellitus (requires dose adjustment and glucose monitoring) - Caution with cardiac conduction disorders (bradycardia, QT prolongation risk) - Caution with hypothyroidism (TSH suppression effect may worsen subclinical hypothyroidism) - Pregnancy (limited data; use only if clearly necessary and benefits outweigh risks) ## FAQ ### What is Octreotide and what is it used for? Octreotide is a synthetic somatostatin analog FDA-approved for acromegaly, carcinoid syndrome, and VIPomas. It broadly inhibits growth hormone, glucagon, insulin, and multiple gut hormones by binding somatostatin receptors SSTR2, SSTR3, and SSTR5 with a half-life of 1.7 hours for immediate-release formulation. ### How does Octreotide treat acromegaly? Octreotide suppresses GH secretion from pituitary adenomas and reduces circulating IGF-1 levels by activating somatostatin receptors. Long-term treatment can stabilize and sometimes reduce pituitary tumor volume. Starting doses are 50 mcg three times daily, titrated to 100 to 250 mcg three times daily. ### What is the difference between Sandostatin and Sandostatin LAR? Sandostatin is the immediate-release injectable form requiring two to four daily subcutaneous injections. Sandostatin LAR is a long-acting depot formulation given once every 28 days by intramuscular injection at 10, 20, or 30 mg doses. Patients typically start on immediate-release to establish tolerability before switching. ### What are Octreotide side effects? Common effects include nausea, diarrhea, abdominal cramping, constipation, injection site reactions, headache, and fatigue. The most significant long-term concern is gallstone formation from reduced gallbladder contractility, with prevalence increasing significantly during chronic use. Periodic ultrasound monitoring is recommended. ### Does Octreotide cause gallstones? Yes. Octreotide reduces gallbladder contractility, leading to bile stasis and stone formation. Gallstone prevalence increases significantly with chronic use, making periodic gallbladder ultrasound monitoring an important part of long-term octreotide therapy. This is the most clinically relevant long-term adverse effect. ### Can Octreotide affect blood sugar? Yes. Octreotide suppresses both insulin and glucagon, and the net glycemic effect is variable. It may cause either hypoglycemia or hyperglycemia depending on individual physiology and concurrent medications. Blood glucose monitoring is essential, particularly in diabetic patients or those on glucose-lowering medications. ## References 1. Lamberts SWJ, van der Lely AJ, de Herder WW, et al.. "Octreotide." *N Engl J Med*, 1996. PMID: 8532003. https://pubmed.ncbi.nlm.nih.gov/8532003/ 2. Rinke A, Muller HH, Schade-Brittinger C, et al.. "Placebo-controlled, double-blind, prospective, randomized study on the effect of octreotide LAR in the control of tumor growth in patients with metastatic neuroendocrine midgut tumors: a report from the PROMID Study Group." *J Clin Oncol*, 2009. PMID: 19704057. https://pubmed.ncbi.nlm.nih.gov/19704057/ 3. Ezzat S, Snyder PJ, Young WF, et al.. "Octreotide treatment of acromegaly. A randomized, multicenter study." *Ann Intern Med*, 1992. PMID: 1416572. https://pubmed.ncbi.nlm.nih.gov/1416572/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Octreotide is FDA-approved for specific indications including acromegaly and carcinoid tumors; all other uses described here are investigational or off-label. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/octreotide --- # AICAR **AICAR (5-Aminoimidazole-4-Carboxamide Ribonucleoside)** Category: Endurance > AMPK Activator for Endurance and Metabolic Performance AICAR (acadesine) is a nucleoside analogue that activates AMP-activated protein kinase (AMPK), simulating metabolic adaptations associated with endurance exercise. Research has demonstrated increases in mitochondrial biogenesis, fatty acid oxidation, and oxidative fiber specification in skeletal muscle. AICAR is prohibited under the WADA Prohibited List and has no FDA-approved therapeutic indication. ## Key Facts - **Molecular weight:** 258.23 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/17513/property/MolecularFormula,MolecularWeight,IUPACName,CanonicalSMILES/JSON) - **Molecular formula:** C9H14N4O5 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/17513/property/MolecularFormula,MolecularWeight,IUPACName,CanonicalSMILES/JSON) - **Primary target:** AMP-activated protein kinase (AMPK); activated indirectly via the AMP-mimetic metabolite ZMP (also inhibits AMP deaminase and modulates adenosine signaling) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC8147799/) - **Mechanism class:** AMPK activator (AMP-mimetic nucleoside analogue / adenosine-regulating agent) (source: https://pubmed.ncbi.nlm.nih.gov/18457469/) - **Half-life:** Intact acadesine cleared rapidly (measurable in plasma only ~2 h after a 15-min IV infusion); terminal half-life of total radioactivity ~1 week, reflecting the uric acid metabolite. Total plasma clearance 2.2 +/- 0.2 L/h/kg (source: https://pubmed.ncbi.nlm.nih.gov/8227467/) - **Route of administration:** Intravenous infusion in human clinical studies (CABG trials); supplied for research use as lyophilized powder reconstituted for subcutaneous or intramuscular injection (source: https://pubmed.ncbi.nlm.nih.gov/8227467/) - **Regulatory status:** No FDA-approved therapeutic indication; investigational (reached Phase III for myocardial protection in CABG but failed for efficacy). Prohibited at all times under the WADA Prohibited List since 2009 as a metabolic modulator (AMPK activator) (source: https://www.usada.org/spirit-of-sport/education/aicar-and-other-prohibited-amp-activated-protein-kinase-activators/) - **CAS number:** 2627-69-2 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/17513/xrefs/RN/JSON) ## Overview AICAR (5-aminoimidazole-4-carboxamide ribonucleoside, also written as acadesine or AICA-riboside) is a nucleoside analogue that is taken up by cells and phosphorylated to form ZMP, a structural analogue of AMP. ZMP accumulation mimics the cell's perception of low energy status by activating AMP-activated protein kinase (AMPK), a central metabolic sensor that governs cellular energy homeostasis across virtually all tissues. AMPK is sometimes described as the cell's master energy switch: it is activated when the AMP-to-ATP ratio rises and it orchestrates a coordinated response to restore energy balance. By activating AMPK pharmacologically without requiring actual energy stress, AICAR simulates many of the adaptive metabolic responses associated with endurance exercise. Key downstream effects include increased mitochondrial biogenesis, enhanced fatty acid oxidation, upregulation of glucose transporter expression (GLUT-4 and GLUT-1), increased oxidative fiber specification in skeletal muscle, and improved insulin sensitivity. Research published in Cell in 2008 by Evans and colleagues at the Salk Institute demonstrated that four weeks of AICAR administration in sedentary mice enhanced running endurance by 44% and induced a gene expression profile in skeletal muscle resembling that of trained athletes, without any exercise training. Subsequent research has provided important nuance. A systematic review published in Cells in 2021 documented that AICAR has numerous biological effects that are independent of AMPK activation, complicating the interpretation of earlier research. AICAR also inhibits AMP deaminase, affects adenosine signaling, and alters purine synthesis pathways. These off-target effects can influence inflammation, immune function, and cardiovascular biology in ways that are not fully characterized. AICAR has been on the World Anti-Doping Agency (WADA) Prohibited List since 2009, classified under Hormone and Metabolic Modulators. It is prohibited at all times in competitive sport due to its potential to enhance endurance performance. AICAR has no FDA-approved therapeutic indication and is an investigational research compound available for laboratory and preclinical research use only. ## Dosage Route: Subcutaneous or intramuscular injection (reconstituted from lyophilized powder) ### Schedule | Period | Dose | | --- | --- | | Sedentary mice (Evans lab, Cell 2008) | 500 mg/kg/day IP for 4 weeks | | Various rodent studies | 250-500 mg/kg/day | | Estimated human equivalent (60 kg adult) | ~42 mg/kg (single dose pharmacokinetics studied) | | Human tolerability study | Up to 210 mg/kg single dose | ### Reconstitution - Vial size: Varies by supplier - Water volume: Per vial labeling with sterile saline or bacteriostatic water - Concentration: Per vial labeling - Per unit: Varies by reconstitution volume ### Tips - AICAR is typically supplied as a lyophilized powder and is reconstituted with sterile saline or bacteriostatic water for injection - Reconstituted solutions should be stored at 2-8 degrees Celsius and used within 30 days - Rodent doses of 250-500 mg/kg do not translate reliably to human equivalent doses for performance purposes - No standard human dosing protocol exists with validated safety and efficacy data - Prohibited at all times under WADA rules; competitive athletes should not use AICAR ## Side Effects ### Common - Hypoglycemia: AICAR increases glucose uptake and utilization via AMPK activation and GLUT-4 upregulation; risk is amplified in fasted individuals or those taking glucose-lowering medications - Fatigue and dizziness, potentially related to acute hypoglycemia - Gastrointestinal discomfort including nausea, bloating, and loose stools - Injection site reactions with subcutaneous or intramuscular administration - Hyperuricemia (elevated uric acid) affecting purine metabolism, which may precipitate gout ### Severe / Theoretical Risks - **Severe hypoglycemia**: The glucose-lowering effects of AICAR can be clinically significant, particularly at higher doses or in combination with insulin, metformin, or sulfonylureas. Symptomatic hypoglycemia requiring intervention has been reported in research contexts. - **Cardiac arrhythmia**: AICAR has complex effects on cardiac electrophysiology via AMPK and adenosine pathways. Arrhythmias have been observed in preclinical cardiac studies at high doses. - **Unknown long-term consequences**: AICAR's AMPK-independent effects (particularly on adenosine signaling, purine biosynthesis, and immune function) are not fully characterized over extended administration. - **Immunosuppression**: AMPK activation and adenosine pathway modulation can suppress immune responses, potentially increasing susceptibility to infection. ### Contraindications - Diabetes mellitus or any condition requiring tight glycemic control (severe hypoglycemia risk) - Concurrent use of insulin, sulfonylureas, or other hypoglycemic agents - Gout or hyperuricemia - Pre-existing cardiac arrhythmia or conduction defects - Immunocompromised states or active infection - Pregnancy and breastfeeding (no safety data) - Pediatric use - Competitive athletes subject to WADA anti-doping rules (AICAR is prohibited at all times) ## FAQ ### What is AICAR and how does it mimic exercise? AICAR is a nucleoside analog that activates AMP-activated protein kinase (AMPK), the cell's master energy sensor. By mimicking low energy status, it triggers metabolic adaptations normally produced by endurance exercise, including increased mitochondrial biogenesis, enhanced fatty acid oxidation, and improved insulin sensitivity. ### Did AICAR really improve endurance without exercise? Yes. A landmark 2008 study published in Cell demonstrated that four weeks of AICAR in sedentary mice enhanced running endurance by 44% and induced a skeletal muscle gene expression profile resembling trained athletes, all without any exercise training. However, these results have not been replicated in human trials. ### Is AICAR banned in sports? Yes. AICAR has been on the World Anti-Doping Agency (WADA) Prohibited List since 2009, classified under Hormone and Metabolic Modulators. It is prohibited at all times in competitive sport due to its potential to enhance endurance performance. Competitive athletes should not use AICAR under any circumstances. ### What are AICAR side effects? The most significant risk is hypoglycemia from increased glucose uptake via AMPK activation and GLUT-4 upregulation. Other effects include fatigue, dizziness, gastrointestinal discomfort, hyperuricemia that may trigger gout, and potential cardiac arrhythmia at high doses through adenosine pathway effects. ### Is there a safe AICAR dosage for humans? No standard human dosing protocol exists with validated safety and efficacy data. Rodent doses of 250 to 500 mg/kg do not translate reliably to human equivalents. Human tolerability studies have tested up to 210 mg/kg as a single dose, but chronic dosing protocols remain entirely unvalidated for performance use. ### Is AICAR FDA approved? AICAR has no FDA-approved therapeutic indication and remains an investigational research compound. It was studied as a potential cardioprotective agent during cardiac surgery but never completed the regulatory approval process. Its use outside of controlled research settings constitutes self-experimentation with uncharacterized risks. ## References 1. Narkar VA, Downes M, Yu RT, et al.. "AMPK and PPARdelta agonists are exercise mimetics." *Cell*, 2008. PMID: 18674809. https://pubmed.ncbi.nlm.nih.gov/18674809/ 2. Merrill GF, Kurth EJ, Hardie DG, et al.. "AICA riboside increases AMP-activated protein kinase, fatty acid oxidation, and glucose uptake in rat muscle." *Am J Physiol*, 1997. PMID: 9435525. https://pubmed.ncbi.nlm.nih.gov/9435525/ 3. Visnjic D, Lalic H, Bhatt RR, et al.. "AICAr, a Widely Used AMPK Activator with Important AMPK-Independent Effects: A Systematic Review." *Cells*, 2021. PMID: 34064363. https://pubmed.ncbi.nlm.nih.gov/34064363/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. AICAR has not been approved by the FDA for any medical condition. AICAR is prohibited under the World Anti-Doping Agency (WADA) Prohibited List. Always consult with a qualified healthcare professional before starting any research compound. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/aicar --- # SR-9011 **SR-9011** Category: Endurance > REV-ERB Agonist for Endurance and Metabolic Health SR-9011 is a synthetic small molecule REV-ERB nuclear receptor agonist that modulates circadian rhythm machinery and metabolic pathways governing energy expenditure, lipid oxidation, and inflammatory responses. Preclinical studies show increased metabolic rate, reduced fat mass, and improved glucose tolerance, with related REV-ERB agonists showing enhanced exercise capacity in animal models. No human clinical trials have been conducted. ## Key Facts - **Molecular weight:** 479.0 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/57394021/property/MolecularFormula,MolecularWeight/JSON) - **Molecular formula:** C23H31ClN4O3S (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/57394021/property/MolecularFormula,MolecularWeight/JSON) - **Primary target:** REV-ERBalpha and REV-ERBbeta nuclear receptors (NR1D1/NR1D2); IC50 790 nM and 560 nM respectively (source: https://www.guidetopharmacology.org/GRAC/LigandDisplayForward?tab=biology&ligandId=8900) - **Mechanism class:** REV-ERB nuclear receptor agonist (source: https://pubmed.ncbi.nlm.nih.gov/22460951/) - **Route of administration:** Intraperitoneal (i.p.) in animal studies (100 mg/kg twice daily in mice); no validated human route; characterized by high metabolic clearance (source: https://pubmed.ncbi.nlm.nih.gov/22460951/) - **Regulatory status:** Research-use-only; not approved for human use by FDA or EMA; no human clinical trials conducted (source: https://en.wikipedia.org/wiki/SR9011) - **CAS number:** 1379686-29-9 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/57394021/JSON?heading=CAS) ## Overview SR-9011 is a synthetic small molecule that acts as a potent agonist of REV-ERB nuclear receptors, specifically REV-ERBa and REV-ERBb. These receptors function as transcriptional repressors that sit at the intersection of circadian rhythm regulation and metabolic homeostasis. By pharmacologically activating REV-ERB, SR-9011 directly modulates the molecular clock machinery and simultaneously engages metabolic pathways governing energy expenditure, lipid oxidation, gluconeogenesis, adipogenesis, and inflammatory responses. It is classified as a research compound and has no approved clinical use. The biological role of REV-ERBa is to act as a heme-sensing transcriptional repressor, binding to response elements in the promoters of core circadian clock genes (including Bmal1 and Clock) and metabolic target genes. When SR-9011 activates REV-ERBa, it reinforces the repressor function of these receptors, shifting circadian gene expression in ways that alter the timing and magnitude of metabolic activity. Published preclinical research in the journal Nature (2012) showed that pharmacological REV-ERB activation with SR-9011 increased metabolic rate, reduced fat mass, decreased plasma triglycerides and cholesterol, and improved glucose tolerance in diet-induced obese mice. The endurance and exercise-related interest in SR-9011 stems from its effects on skeletal muscle energy metabolism. Animal studies have shown that REV-ERB activation increases oxidative capacity in muscle cells, promoting mitochondrial biogenesis and fatty acid oxidation pathways that parallel those engaged during aerobic exercise. The endurance-related properties of REV-ERB agonists have been demonstrated with related compounds in preclinical models through enhanced mitochondrial biogenesis and oxidative capacity in skeletal muscle. Direct endurance testing data specific to SR-9011 are limited in the published literature, and all human pharmacokinetic and efficacy data are absent, as no human clinical trials have been conducted. SR-9011 also exhibits anti-inflammatory properties mediated through REV-ERBa's role in macrophage function. Research published in 2020 demonstrated that SR-9011 suppressed pro-inflammatory cytokine production in microglia, the resident immune cells of the central nervous system. This neuroinflammatory modulation adds another dimension to the compound's research interest, particularly in the context of neurodegenerative disease models. SR-9011 has a short estimated half-life of approximately 4 hours in preclinical models, which has significant implications for dosing strategy in any future human application. ## Dosage Route: Intraperitoneal in animal studies; oral bioavailability uncertain; no validated human protocol ### Schedule | Period | Dose | | --- | --- | | Animal research protocol | 100 mg/kg intraperitoneally, twice daily | ### Reconstitution - Vial size: Research powder - Water volume: DMSO stock solution, then aqueous dilution for administration - Concentration: EC50 (REV-ERBa): 790 nM; EC50 (REV-ERBb): 560 nM - Per unit: No validated human reconstitution protocol exists in published literature ### Tips - No established human dosing protocol exists; all data are preclinical - The short half-life (approximately 4 hours in animal data) suggests multiple daily dosing would likely be required to maintain receptor occupancy - A single daily dose would likely result in significant pharmacodynamic gaps - For laboratory use, SR-9011 is commonly dissolved in DMSO for stock solution preparation, then diluted in aqueous vehicle - No subcutaneous or oral dosing protocols have been validated ## Side Effects ### Common - Disruption of normal circadian rhythms: REV-ERB activation suppresses Bmal1, a core clock gene; single-dose administration in animal studies produced loss of normal locomotor activity patterns for approximately 24 hours - Alterations in sleep architecture - Reduced gluconeogenesis, which may cause hypoglycemia in fasted states - Appetite suppression (observed in animal models) ### Severe / Theoretical Risks - **Unknown long-term safety profile**: No chronic toxicology data exist in humans or primates. Long-term consequences of sustained REV-ERB activation are entirely unknown. - **Immune modulation**: REV-ERBa regulates macrophage inflammatory responses. Chronic suppression could theoretically impair immune defense against pathogens or malignancy. - **Circadian disruption at higher doses**: Prolonged suppression of core clock genes could have unpredictable systemic consequences affecting metabolic, immune, and neurological function. ### Contraindications - Do not use in pregnancy or breastfeeding - Do not use in individuals with known circadian rhythm disorders - Avoid in individuals with immune compromise - Do not use concurrently with other circadian-modulating compounds without professional oversight ## FAQ ### What is SR-9011 and how does it work? SR-9011 is a synthetic REV-ERB nuclear receptor agonist that modulates circadian rhythm machinery and metabolic pathways. By activating REV-ERB, it shifts gene expression to increase energy expenditure, enhance lipid oxidation, reduce fat mass, and improve glucose tolerance. All data are preclinical with no human trials conducted. ### Does SR-9011 improve endurance? Preclinical studies show SR-9011 increases oxidative capacity in muscle cells, promotes mitochondrial biogenesis, and enhances fatty acid oxidation. Related REV-ERB agonists have demonstrated enhanced oxidative capacity in skeletal muscle in preclinical models. However, all human pharmacokinetic and efficacy data are absent, making performance claims entirely unvalidated in humans. ### How does SR-9011 differ from SR-9009? Both are REV-ERB agonists targeting similar metabolic pathways. SR-9009 was developed earlier and has more published research. SR-9011 has improved potency at REV-ERBb (560 nM vs higher EC50 for SR-9009). Both have short half-lives of approximately 4 hours and no validated human dosing protocols. ### What are SR-9011 side effects? Known effects from animal studies include disruption of normal circadian rhythms with loss of normal locomotor patterns for about 24 hours after dosing, altered sleep architecture, reduced gluconeogenesis causing potential hypoglycemia, and appetite suppression. Long-term safety in any species beyond rodents is entirely unknown. ### Is SR-9011 safe for humans? No human safety data exist for SR-9011. The compound has no chronic toxicology data in any species beyond rodents. Prolonged suppression of core clock genes could have unpredictable effects on metabolic, immune, and neurological function. Its use in humans represents uncharacterized self-experimentation. ### Is there a human dosage for SR-9011? No established human dosing protocol exists. Animal research used 100 mg/kg intraperitoneally twice daily. The short half-life of approximately 4 hours suggests multiple daily doses would be needed to maintain receptor occupancy. Oral bioavailability in humans is uncertain and no subcutaneous protocols have been validated. ## References 1. Solt LA, Wang Y, Banerjee S, et al.. "Regulation of circadian behaviour and metabolism by synthetic REV-ERB agonists." *Nature*, 2012. PMID: 22460951. https://pubmed.ncbi.nlm.nih.gov/22460951/ 2. Sulli G, Rommel A, Wang X, et al.. "Pharmacological activation of REV-ERBs is lethal in cancer and oncogene-induced senescence." *Nature*, 2018. PMID: 29320480. https://pubmed.ncbi.nlm.nih.gov/29320480/ 3. Banerjee S, Wang Y, Solt LA, et al.. "Pharmacological targeting of the mammalian clock regulates sleep architecture and emotional behaviour." *Nat Commun*, 2014. PMID: 25536025. https://pubmed.ncbi.nlm.nih.gov/25536025/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. SR-9011 has not been approved by the FDA for any medical condition and is classified as a research compound only. No human clinical trial data exist for SR-9011. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/sr-9011 --- # SLU-PP-332 **SLU-PP-332** Category: Endurance > ERR Pan-Agonist Exercise Mimetic for Endurance SLU-PP-332 is a synthetic pan-agonist of estrogen-related receptors (ERRa, ERRb, ERRg) developed at Saint Louis University. It reproduces cellular adaptations associated with aerobic exercise by activating gene networks governing mitochondrial biogenesis and fatty acid oxidation. Animal studies show 20-30% improvements in running endurance. No human clinical trials have been conducted. ## Key Facts - **Molecular weight:** 290.3 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/5338394) - **Molecular formula:** C18H14N2O2 (source: https://pubchem.ncbi.nlm.nih.gov/compound/5338394) - **Primary target:** Estrogen-related receptor alpha (ERRa); pan-agonist across ERRa/b/g (EC50 ~0.22 microM at ERRa) (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC13112601/) - **Mechanism class:** Pan-ERR (estrogen-related receptor) agonist; exercise mimetic (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC10801787/) - **Route of administration:** Intraperitoneal in published murine studies; oral bioavailability under investigation; no validated human protocol (source: https://pmc.ncbi.nlm.nih.gov/articles/PMC13112601/) - **Regulatory status:** Research-use-only; not FDA/EMA approved for any indication; no human clinical trials initiated (preclinical only as of 2026) (source: https://clinicaltrials.gov/search?term=SLU-PP-332) - **CAS number:** 303760-60-3 (source: https://pubchem.ncbi.nlm.nih.gov/compound/5338394) ## Overview SLU-PP-332 is a synthetic compound developed at Saint Louis University that functions as a pan-agonist of estrogen-related receptors (ERRs), specifically targeting ERRa, ERRb, and ERRg with highest potency at ERRa. Estrogen-related receptors are nuclear transcription factors that regulate gene networks governing oxidative metabolism, mitochondrial biogenesis, and energy homeostasis. Because these pathways are also activated by endurance exercise, SLU-PP-332 is classified as an exercise mimetic: a compound that reproduces cellular adaptations associated with aerobic physical activity through pharmacological means rather than mechanical work. The molecular mechanism centers on ERRa's control of the DDIT4 (DNA damage-inducible transcript 4) pathway. Research published in ACS Chemical Biology (2022) demonstrated that SLU-PP-332 treatment induces DDIT4 expression specifically through ERRa activation, recapitulating a key genetic response observed after short bouts of aerobic exercise in humans. Downstream of this activation, genes encoding proteins involved in fatty acid oxidation, oxidative phosphorylation, and mitochondrial function are upregulated in skeletal muscle cells, producing a metabolic state resembling aerobic-trained muscle. This mechanism is distinct from REV-ERB agonists like SR-9011 or PPAR delta agonists like GW501516; ERR agonists occupy a unique node in the exercise-responsive transcriptional network. In animal studies, SLU-PP-332 produced measurable gains in exercise endurance. Mice treated with the compound and placed on running protocols showed 20 to 30% improvements in running distance and time compared to vehicle-treated controls, along with increased proportions of type IIa oxidative muscle fibers, which are associated with sustained aerobic effort. Whole-body metabolic studies showed increased energy expenditure and enhanced fatty acid oxidation, accompanied by reduced fat mass accumulation over time without changes in food intake. A 2023 study published in the Journal of Pharmacology and Experimental Therapeutics demonstrated that ERRa agonism with SLU-PP-332 effectively reduced obesity and improved insulin sensitivity in murine models of metabolic syndrome. The research interest in SLU-PP-332 extends to its potential role in aging, sarcopenia, and conditions where exercise capacity is limited by disease or disability. The ability to pharmacologically engage aerobic exercise gene programs could theoretically benefit patients with heart failure, COPD, mobility limitations, or severe obesity who cannot engage in sufficient physical activity. No human clinical trials have been initiated as of early 2026, and all efficacy and safety data are preclinical. ## Dosage Route: Intraperitoneal in published murine studies; oral bioavailability under investigation; no validated human protocol ### Schedule | Period | Dose | | --- | --- | | Animal studies | Varied intraperitoneal dosing; specific mg/kg protocols vary by study | ### Reconstitution - Vial size: 500 mcg research vials (common supplier format) - Water volume: DMSO for stock preparation; further aqueous dilution for administration - Concentration: High nanomolar range EC50 at ERRa (specific value varies by assay) - Per unit: No validated human reconstitution or administration protocol exists ### Tips - No established human dosing protocol exists; all data are preclinical - Pharmacokinetic data in humans are unavailable; animal studies suggest moderate clearance - Frequency and duration of dosing for sustained ERR activation in humans have not been characterized - For laboratory use, typically dissolved in DMSO for stock preparation - Human bioavailability and safe dose ranges remain unknown ## Side Effects ### Common - Appetite changes: metabolic activation may alter feeding behavior - Potential fatigue or altered energy balance in initial use period - Uncertain cardiovascular effects at higher doses (increased cardiac energy demand) ### Severe / Theoretical Risks - **No chronic toxicology data**: No chronic toxicology data exist in any species beyond rodents. Long-term safety in humans is entirely unknown. - **Off-target ERR effects**: ERR receptors are expressed in numerous tissue types including heart, brain, kidney, and liver. Systemic ERR agonism may produce off-target effects not yet characterized. - **Potential oncological risk**: ERRa interacts with pathways involved in breast and other cancer cell proliferation. The implications of pan-ERR agonism for oncological risk are unknown and are an active area of investigation. - **Immunological effects**: ERR receptors modulate immune cell function. Chronic activation may alter immune surveillance in ways not yet characterized. ### Contraindications - Do not use in pregnancy or breastfeeding - Avoid in individuals with active or prior hormone-sensitive cancers - Avoid concurrent use with other nuclear receptor-targeting compounds without expert oversight - Not appropriate for pediatric use ## FAQ ### What is SLU-PP-332 and how does it mimic exercise? SLU-PP-332 is a synthetic pan-agonist of estrogen-related receptors (ERRs) developed at Saint Louis University. It reproduces cellular adaptations of aerobic exercise by activating gene networks governing mitochondrial biogenesis and fatty acid oxidation. Animal studies show 20 to 30% improvements in running endurance without training. ### How does SLU-PP-332 differ from other exercise mimetics? SLU-PP-332 targets ERR receptors, which occupy a unique node in the exercise-responsive transcriptional network distinct from REV-ERB agonists like SR-9011 or PPAR delta agonists like GW501516. It specifically induces DDIT4 expression through ERRa, recapitulating a key genetic response observed after short bouts of human aerobic exercise. ### What results has SLU-PP-332 shown in studies? Treated mice showed 20 to 30% improvements in running distance and time, increased type IIa oxidative muscle fibers, higher energy expenditure, enhanced fatty acid oxidation, and reduced fat mass without changes in food intake. A 2023 study also showed reduced obesity and improved insulin sensitivity in metabolic syndrome models. ### Is SLU-PP-332 safe for humans? No human safety data exist for SLU-PP-332. All efficacy and safety data are preclinical. ERR receptors are expressed in numerous tissues including heart, brain, kidney, and liver, so systemic ERR agonism may produce off-target effects not yet characterized. No clinical trials have been initiated as of early 2026. ### What are SLU-PP-332 side effects? Potential effects include appetite changes, altered energy balance, and uncertain cardiovascular effects from increased cardiac energy demand. Serious concerns include no chronic toxicology data in any species, off-target ERR effects in non-muscle tissues, potential oncological risk from ERRa interactions with cancer pathways, and unknown immune effects. ### Is there a human dosage for SLU-PP-332? No. Human bioavailability, safe dose ranges, and dosing frequency for sustained ERR activation have not been characterized. Animal studies used varied intraperitoneal dosing. The compound is typically dissolved in DMSO for laboratory use. Any human use constitutes entirely unvalidated self-experimentation. ## References 1. Billon C, Sitaula S, Banerjee S, et al.. "Synthetic ERRalpha/beta/gamma Agonist Induces an ERRalpha-Dependent Acute Aerobic Exercise Response and Enhances Exercise Capacity." *ACS Chem Biol*, 2023. PMID: 36988910. https://pubmed.ncbi.nlm.nih.gov/36988910/ 2. Billon C, Sitaula S, Banerjee S, et al.. "A Synthetic ERR Agonist Alleviates Metabolic Syndrome." *J Pharmacol Exp Ther*, 2024. PMID: 37739806. https://pubmed.ncbi.nlm.nih.gov/37739806/ 3. Avliyakulov NK, Deventer K, Van Eenoo P. "Analysis and Identification of In Vitro Metabolites of Exercise Mimetic SLU-PP-332 ERRalpha/beta/gamma Agonist for Doping-Control Purposes." *Drug Test Anal*, 2026. PMID: 41688415. https://pubmed.ncbi.nlm.nih.gov/41688415/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. SLU-PP-332 has not been approved by the FDA for any medical condition and is classified as a research compound only. No human clinical trial data exist for SLU-PP-332. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/slu-pp-332 --- # Teriparatide **Teriparatide (PTH 1-34 / Forteo)** Category: Bone Health > Anabolic Parathyroid Hormone Fragment for Bone Health Teriparatide is the recombinant form of the first 34 amino acids of human parathyroid hormone and the only FDA-approved anabolic (bone-building) agent for osteoporosis treatment in the United States (Forteo/Bonsity). A single daily subcutaneous injection produces a transient PTH pulse that stimulates osteoblasts and increases bone formation, reducing vertebral fracture risk by 65% and nonvertebral fracture risk by 53% in pivotal clinical trials. ## Key Facts - **Molecular weight:** 4117.8 g/mol (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=aae667c5-381f-4f92-93df-2ed6158d07b0) - **Molecular formula:** C181H291N55O51S2 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16133850) - **Sequence length:** 34 (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=aae667c5-381f-4f92-93df-2ed6158d07b0) - **Primary target:** Parathyroid hormone 1 receptor (PTH1R) (source: https://www.guidetopharmacology.org/GRAC/LigandDisplayForward?tab=biology&ligandId=4448) - **Mechanism class:** Parathyroid hormone analog / PTH1 receptor agonist (anabolic bone-forming agent) (source: https://www.guidetopharmacology.org/GRAC/LigandDisplayForward?tab=biology&ligandId=4448) - **Half-life:** ~1 hour (subcutaneous); ~5 minutes true elimination half-life after IV administration (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=aae667c5-381f-4f92-93df-2ed6158d07b0) - **Route of administration:** Subcutaneous injection, once daily (source: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=aae667c5-381f-4f92-93df-2ed6158d07b0) - **Regulatory status:** FDA-approved (Forteo, Eli Lilly, November 2002) for treatment of osteoporosis in postmenopausal women and men at high fracture risk, and glucocorticoid-induced osteoporosis; prescription-only (source: https://www.accessdata.fda.gov/drugsatfda_docs/appletter/2002/21318.pdf) - **CAS number:** 52232-67-4 (source: https://pubchem.ncbi.nlm.nih.gov/compound/16133850) ## Overview Teriparatide is the recombinant form of the first 34 amino acids of human parathyroid hormone (PTH 1-34), the biologically active N-terminal fragment of the 84-amino-acid endogenous parathyroid hormone. It is produced via recombinant DNA technology in Escherichia coli. Teriparatide is the only FDA-approved anabolic (bone-building) agent for osteoporosis treatment in the United States, available under the brand names Forteo and Bonsity, and represents a fundamentally different pharmacological approach to bone loss compared to antiresorptive agents such as bisphosphonates and denosumab. The distinction between teriparatide's anabolic effects and the catabolic effects of endogenous PTH overproduction lies entirely in the pattern of exposure. Chronic continuous elevation of parathyroid hormone (as occurs in primary hyperparathyroidism) drives net bone resorption and cortical bone thinning. Intermittent administration of low-dose teriparatide (a daily subcutaneous injection that produces a transient pulse of PTH activity) produces the opposite effect: net bone formation exceeds resorption. The mechanism involves direct stimulation of osteoblasts (bone-forming cells), suppression of osteoblast apoptosis, activation of resting bone surfaces previously not undergoing remodeling, and indirect modulation of osteoclast activity. The result is an increase in both trabecular bone volume and cortical bone thickness. Clinical evidence for teriparatide is robust. In the pivotal randomized controlled trial in postmenopausal women with prior vertebral fractures (n=1,637), 20 mcg daily teriparatide over a median of 21 months reduced new vertebral fracture risk by 65% and nonvertebral fragility fracture risk by 53%, while increasing lumbar spine bone mineral density (BMD) by 9% and femoral neck BMD by 3%. A 2024 systematic review and meta-analysis comparing teriparatide with other anabolic agents confirmed its substantial benefits in lumbar spine and hip BMD gains and fracture risk reduction, particularly in patients at high fracture risk. Teriparatide is FDA-approved for postmenopausal women with osteoporosis at high fracture risk, men with primary or hypogonadal osteoporosis at high fracture risk, and men and women with glucocorticoid-induced osteoporosis at high fracture risk. Treatment duration is limited to 24 months cumulative lifetime due to preclinical findings of osteosarcoma in rats given very high doses over extended periods -- a risk that has not been demonstrated in human clinical trials. ## Dosage Route: Subcutaneous injection, once daily ### Schedule | Period | Dose | | --- | --- | | Postmenopausal osteoporosis | 20 mcg once daily SQ (maximum 24 months lifetime) | | Male osteoporosis (primary or hypogonadal) | 20 mcg once daily SQ (maximum 24 months lifetime) | | Glucocorticoid-induced osteoporosis | 20 mcg once daily SQ (maximum 24 months lifetime) | ### Reconstitution - Vial size: Supplied as pre-filled injection pen (28-dose, 2.4 mL) -- no reconstitution required - Water volume: N/A (pre-filled pen in sterile solution) - Concentration: 250 mcg/mL - Per unit: Each 20 mcg dose = 0.08 mL from the pre-filled pen ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 20 mcg | 0.08 mL | Fixed dose -- pen auto-delivers 20 mcg per actuation | ### Tips - The first injection should be administered while the patient is sitting or lying down -- transient orthostatic hypotension may occur - Standard injection sites are the thigh and abdominal wall; rotate sites with each injection - The injection pen should be refrigerated at all times -- do not freeze - After removing from the refrigerator, allow the pen to reach room temperature before injecting - Following teriparatide cessation, transition to an antiresorptive therapy (such as a bisphosphonate) is recommended to preserve BMD gains - Treatment is typically reserved for patients at high or very high fracture risk due to the 24-month lifetime use limit - Higher doses did not produce superior BMD outcomes and increased side effect rates in dose-response studies ## Side Effects ### Common - Nausea (approximately 8-18% of patients; usually mild and early in treatment) - Dizziness and leg cramps, particularly within the first few hours after injection - Orthostatic hypotension (transient blood pressure drop shortly after injection, especially with first dose) - Injection site reactions (redness, swelling, bruising, pain -- typically mild) - Mild hypercalcemia (teriparatide increases calcium release from bone; serum calcium should be monitored) - Arthralgia (joint pain) during longer-term use - Elevated serum uric acid levels (hyperuricemia without gout in some studies) ### Severe / Theoretical Risks - **Osteosarcoma**: A black box warning exists based on rat carcinogenicity studies showing osteosarcoma at doses 3 to 60 times the human equivalent dose over the rat lifetime. No cases of osteosarcoma attributable to teriparatide have been confirmed in human clinical trials or post-marketing data, but the theoretical risk informs the 24-month lifetime use restriction. - **Hypercalcemia**: Clinically significant elevations in serum calcium can occur, particularly in patients with pre-existing conditions predisposing to hypercalcemia (hyperparathyroidism, Paget's disease). - **Urolithiasis**: Kidney stone formation; pre-existing nephrolithiasis is a relative contraindication. ### Contraindications - Hypersensitivity to teriparatide or any excipient - Pre-existing hypercalcemia - Metabolic bone diseases other than primary osteoporosis or glucocorticoid-induced osteoporosis (including Paget's disease of bone) - Unexplained elevations of alkaline phosphatase - Prior external beam or implant radiation therapy to the skeleton - Pediatric patients or young adults with open epiphyses - Pregnancy and lactation - Skeletal metastases or prior history of bone malignancy - History of osteosarcoma ## FAQ ### What is Teriparatide and is it FDA approved? Teriparatide is the recombinant form of the first 34 amino acids of human parathyroid hormone and the only FDA-approved anabolic bone-building agent for osteoporosis. Available as Forteo and Bonsity, it stimulates osteoblasts to form new bone rather than just slowing bone loss like bisphosphonates. ### How effective is Teriparatide for osteoporosis? In the pivotal trial of 1,637 postmenopausal women, 20 mcg daily teriparatide reduced new vertebral fracture risk by 65% and nonvertebral fracture risk by 53% over 21 months. Lumbar spine bone mineral density increased by 9% and femoral neck BMD by 3%, demonstrating substantial clinical benefit. ### Why is Teriparatide limited to 24 months? The 24-month cumulative lifetime treatment limit exists because rat studies showed osteosarcoma at high doses over extended periods. No cases of osteosarcoma attributable to teriparatide have been confirmed in human trials or post-marketing data, but the theoretical risk informs this precautionary restriction. ### What are Teriparatide side effects? Common side effects include nausea (8 to 18% of patients), dizziness, leg cramps, orthostatic hypotension especially with the first dose, injection site reactions, mild hypercalcemia, and joint pain. The first injection should be given while sitting or lying down to prevent falls from blood pressure drops. ### What happens when you stop Teriparatide? Bone mineral density gains from teriparatide can be lost after discontinuation. Transitioning to an antiresorptive therapy such as a bisphosphonate after completing the teriparatide course is recommended to preserve the bone density gains achieved during the anabolic treatment phase. ### How is Teriparatide administered? Teriparatide is supplied as a pre-filled injection pen delivering a fixed 20 mcg dose per actuation. It is injected subcutaneously once daily into the thigh or abdominal wall, with site rotation. The pen must be refrigerated at all times and should never be frozen. ## References 1. Neer RM, Arnaud CD, Zanchetta JR, et al.. "Effect of parathyroid hormone (1-34) on fractures and bone mineral density in postmenopausal women with osteoporosis." *N Engl J Med*, 2001. PMID: 11346808. https://pubmed.ncbi.nlm.nih.gov/11346808/ 2. Saag KG, Shane E, Boonen S, et al.. "Teriparatide or alendronate in glucocorticoid-induced osteoporosis." *N Engl J Med*, 2007. PMID: 18003959. https://pubmed.ncbi.nlm.nih.gov/18003959/ 3. Body JJ, Gaich GA, Scheele WH, et al.. "A randomized double-blind trial to compare the efficacy of teriparatide [recombinant human parathyroid hormone (1-34)] with alendronate in postmenopausal women with osteoporosis." *J Clin Endocrinol Metab*, 2002. PMID: 12364430. https://pubmed.ncbi.nlm.nih.gov/12364430/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Teriparatide is FDA-approved under specific brand names for specific indications; use outside those approved indications may be off-label. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/teriparatide --- # Prostamax **Prostamax (KEDP)** Category: Prostate Health > Tetrapeptide Bioregulator for Prostate Health Prostamax is a short-chain tetrapeptide bioregulator (Lys-Glu-Asp-Pro) from the Khavinson peptide family, designed to restore gene expression in prostate tissue that has undergone age-related decline. Early clinical research associates it with reduced inflammatory markers in chronic prostatitis and inhibition of sclerotic processes in prostate tissue. ## Key Facts - **Molecular weight:** 487.5 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/9848296/property/MolecularFormula,MolecularWeight,IUPACName,CanonicalSMILES/JSON) - **Molecular formula:** C20H33N5O9 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/9848296/property/MolecularFormula,MolecularWeight,IUPACName,CanonicalSMILES/JSON) - **Sequence length:** 4 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/9848296/property/MolecularFormula,MolecularWeight,IUPACName,CanonicalSMILES/JSON) - **Mechanism class:** Short peptide bioregulator (Khavinson tetrapeptide); tissue-specific epigenetic/gene-expression regulator (source: https://pubmed.ncbi.nlm.nih.gov/15612551/) - **Regulatory status:** Not FDA/EMA approved; research-use-only. No Western randomized controlled trials; evidence base is preclinical/small Russian-literature studies. Not approved for human therapeutic use. (source: https://pubchem.ncbi.nlm.nih.gov/compound/9848296) - **CAS number:** 473578-47-1 (source: https://pubchem.ncbi.nlm.nih.gov/rest/pug/compound/cid/9848296/synonyms/JSON) ## Overview Prostamax is a short-chain tetrapeptide bioregulator with the amino acid sequence Lys-Glu-Asp-Pro (KEDP). It belongs to a class of compounds known as Khavinson peptides, a family of tissue-specific short peptides originally developed in Russia by Professor Vladimir Khavinson and colleagues at the Saint Petersburg Institute of Bioregulation and Gerontology. These bioregulators are designed to restore gene expression in specific tissues that have undergone age-related decline, and prostamax is the prostate-specific member of this family. The proposed mechanism of action involves epigenetic modulation at the chromatin level. Research indicates that short peptide bioregulators in the Khavinson family can interact with DNA-histone complexes, influencing chromatin structural dynamics in ways that reactivate genes that have become transcriptionally silenced with aging. In prostate tissue specifically, this modulation is associated with restoration of normal epithelial cell proliferation rates, reduction in aberrant apoptosis, and normalization of protein expression patterns characteristic of younger tissue. Published studies have described prostamax exposure in cell models as producing a gene expression profile more consistent with younger prostatic tissue, with enhanced cellular proliferation and reduced pro-senescent signaling. Animal and early clinical research has examined prostamax in the context of chronic prostatitis. The research also noted potential for restraining the development of sclerotic and atrophic processes in the prostate gland, which are hallmarks of chronic inflammatory prostate disease and benign prostatic changes associated with aging. It is important to contextualize the evidence base for prostamax appropriately. The available research is predominantly preclinical or from small, non-blinded clinical studies conducted in the Russian literature, which has not been consistently replicated in large-scale Western randomized controlled trials. Prostamax is not a treatment for prostate cancer. Its proposed role is in supporting prostate tissue health and reducing the functional consequences of chronic inflammation and aging, not in addressing malignant disease. The compound should be understood as a research-stage bioregulator with promising early signals but an evidence base that requires further rigorous investigation. ## Dosage Route: Intramuscular injection (preferred; superior bioavailability) or oral capsules ### Schedule | Period | Dose | | --- | --- | | Injectable cycle (daily) | 500 mcg to 1 mg intramuscularly per day for 10-20 days | | Oral cycle (daily) | 10-20 mg orally once or twice daily with meals for 10-20 days | ### Reconstitution - Vial size: Per supplier specification - Water volume: Sterile bacteriostatic water or 0.9% sodium chloride - Concentration: Per supplier-specific dilution instructions - Per unit: Begin at 500 mcg injectable; increase to 1 mg based on tolerance ### Injection Volumes | Dose | Volume | Units (U-100 syringe) | | --- | --- | --- | | 500 mcg | Per supplier instructions | Intramuscular | | 1 mg | Per supplier instructions | Intramuscular | ### Tips - Injectable form is considered to have superior bioavailability for tissue-specific effect - Begin at 500 mcg injectable; increase to 1 mg based on tolerance - Oral form: take with meals once or twice daily - Standard Khavinson protocols suggest repeating cycles two to four times per year - Allow 3 to 6 months between cycles for ongoing tissue maintenance - Refrigerate reconstituted injectable solution; use within 14 to 30 days ### Cycling - On period: 10-20 days - Off period: 3-6 months between cycles - Notes: Standard Khavinson peptide protocols suggest 2-4 cycles per year. Long-term continuous use protocols have not been formally evaluated. ## Side Effects ### Common - Injection site reactions: localized pain, redness, or swelling with intramuscular administration - Gastrointestinal discomfort with oral form: mild nausea or bloating - Transient fatigue during initial cycle days ### Severe / Theoretical Risks - **Hypersensitivity**: Allergic reactions to peptide components are possible. Discontinue and seek medical attention if rash, urticaria, or breathing difficulty develops. - **Unknown long-term safety profile**: The published evidence base lacks multi-year randomized safety data in Western clinical trial formats. Long-term consequences of chronic epigenetic modulation in prostate tissue are not established. - **Interactions with prostate medications**: Men taking alpha-blockers, 5-alpha reductase inhibitors, or other prostate-targeted therapies should discuss use with a physician before adding prostamax. ### Contraindications - Known hypersensitivity to any component of the formulation - Prostate cancer (prostamax is not indicated for malignant disease and has not been studied in this population) - Pregnancy (not applicable by indication; listed for completeness) - Use in combination with immunosuppressive therapy (theoretical concern given peptide's immune-modulatory effects in tissue models) ## FAQ ### What is Prostamax and what does it do? Prostamax is a tetrapeptide bioregulator (Lys-Glu-Asp-Pro) from the Khavinson peptide family designed to restore gene expression in prostate tissue affected by age-related decline. It works at the epigenetic level, interacting with DNA-histone complexes to reactivate genes silenced by aging in prostate epithelial cells. ### Can Prostamax help with prostatitis? Early clinical research in Russian literature associates prostamax with reduced inflammatory markers in chronic prostatitis and with restraining sclerotic and atrophic processes in prostate tissue. This evidence comes from small, non-blinded studies and has not been independently replicated in large controlled trials. ### What is the Prostamax dosage? Injectable cycles use 500 mcg to 1 mg intramuscularly per day for 10 to 20 days. Oral cycles use 10 to 20 mg once or twice daily with meals for 10 to 20 days. Standard Khavinson protocols suggest repeating cycles two to four times per year with 3 to 6 months between cycles. ### Is Prostamax a treatment for prostate cancer? No. Prostamax is not a treatment for prostate cancer and has not been studied in cancer populations. Its proposed role is supporting prostate tissue health and reducing consequences of chronic inflammation and aging. It is contraindicated in prostate cancer and should not be used as a substitute for oncological treatment. ### What are Prostamax side effects? Common side effects include injection site reactions, gastrointestinal discomfort with oral form, and transient fatigue during initial cycle days. The published evidence base lacks multi-year randomized safety data. Men taking alpha-blockers or 5-alpha reductase inhibitors should consult a physician before adding prostamax. ### Is Prostamax FDA approved? No. Prostamax has not been approved by the FDA for any medical condition. The available research is predominantly preclinical or from small clinical studies in Russian literature that have not been replicated in large-scale Western randomized controlled trials. It remains a research-stage bioregulator. ## References 1. Meskhi T, Dvalishvili N, Naneishvili T, et al.. "The influence of the peptide bioregulator prostamax on heterochromatin of human lymphocytes in situ." *Biofizika*, 2004. PMID: 15612551. https://pubmed.ncbi.nlm.nih.gov/15612551/ 2. Khavinson VKh, Lezhava TA, Malinin VV. "Effects of short peptides on lymphocyte chromatin in senile subjects." *Bull Exp Biol Med*, 2004. PMID: 15085253. https://pubmed.ncbi.nlm.nih.gov/15085253/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Prostamax has not been approved by the FDA for any medical condition. The available evidence base is primarily preclinical or derived from small-scale clinical studies and has not been validated in large Western randomized controlled trials. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/prostamax --- # PTD-DBM **PTD-DBM (Protein Transduction Domain - Dishevelled Binding Motif)** Category: Hair Growth > Wnt Pathway Activator for Hair Growth PTD-DBM is a synthetic fusion peptide combining a Protein Transduction Domain (PTD) for cell membrane penetration with a Dishevelled Binding Motif (DBM) that competitively disrupts the CXXC5-Dishevelled interaction. By releasing this negative feedback on Wnt/beta-catenin signaling, PTD-DBM promotes the anagen (growth) phase of the hair cycle. Research remains exclusively preclinical with no published human trials. ## Key Facts - **Molecular weight:** 3082.6 g/mol (source: https://pubchem.ncbi.nlm.nih.gov/compound/176453931) - **Molecular formula:** C124H225N61O28S2 (source: https://pubchem.ncbi.nlm.nih.gov/compound/176453931) - **Primary target:** CXXC5-Dishevelled (Dvl) protein-protein interaction (binds the PDZ domain of Dvl), releasing negative feedback on the Wnt/beta-catenin signaling pathway (source: https://pubmed.ncbi.nlm.nih.gov/28595998/) - **Mechanism class:** Wnt/beta-catenin pathway activator; cell-penetrating competitor peptide that disrupts the CXXC5-Dishevelled interaction (CXXC5 inhibitor peptide) (source: https://pubmed.ncbi.nlm.nih.gov/28595998/) - **Route of administration:** Topical application to skin/scalp (primary, preclinical); subcutaneous/intradermal injection investigational (source: https://pubmed.ncbi.nlm.nih.gov/28595998/) - **Regulatory status:** Not FDA approved for any indication; preclinical/research-use-only. No published human clinical trials as of 2026 (evidence limited to mouse models and human cell cultures). (source: https://pubmed.ncbi.nlm.nih.gov/28595998/) - **CAS number:** 1609454-11-6 (source: https://pubchem.ncbi.nlm.nih.gov/compound/176453931) ## Overview PTD-DBM is a synthetic fusion peptide combining two functional domains: a Protein Transduction Domain (PTD) and a Dishevelled Binding Motif (DBM). The PTD component enables the peptide to cross cell membranes, a capability that would otherwise require specialized delivery systems for intracellular targets. The DBM component is derived from a region of the CXXC5 protein that normally interacts with Dishevelled (Dvl), an upstream scaffolding protein in the Wnt signaling pathway. By combining these two functional units, PTD-DBM was designed to penetrate cells and interfere with a specific intracellular protein-protein interaction relevant to hair follicle biology. The Wnt/beta-catenin pathway is essential for hair follicle development, maintenance, and cycling through its growth phases. In healthy hair follicles, active Wnt signaling promotes the anagen (growth) phase and supports follicle stem cell activity. The CXXC5 protein acts as a negative feedback regulator in this system by binding to Dishevelled and blocking downstream beta-catenin signaling. In androgenetic alopecia (male and female pattern hair loss), elevated CXXC5 expression (potentially driven by dihydrotestosterone-induced prostaglandin D2 signaling) suppresses Wnt activity and disrupts the hair cycle. PTD-DBM functions by competitively disrupting the CXXC5-Dishevelled interaction. By occupying the Dvl binding site, PTD-DBM prevents CXXC5 from exerting its inhibitory effect, allowing Wnt/beta-catenin signaling to proceed more robustly. Published research from Yonsei University (South Korea) demonstrated that topical application of PTD-DBM in mouse models promoted hair regrowth and extended the anagen phase. When combined with valproic acid (a separate Wnt pathway activator) in animal models, PTD-DBM produced additive hair regrowth effects and also promoted wound-induced hair neogenesis (WIHN), the formation of new hair follicles in healing skin. Research on PTD-DBM remains exclusively preclinical. No human clinical trials have been conducted or published as of early 2026. Published animal studies have not reported significant adverse effects, but the absence of human scalp data means that tolerance, long-term safety, and efficacy in the human hair cycle (which differs structurally from rodent fur cycling) are entirely uncharacterized. ## Dosage Route: Topical application to scalp (primary); subcutaneous or intradermal injection (investigational alternative) ### Schedule | Period | Dose | | --- | --- | | Animal research protocol (topical) | Daily or twice-daily topical application in aqueous solution or hydrogel carrier | | Injectable (investigational) | 1-5 mg per session subcutaneous or intradermal | ### Reconstitution - Vial size: Varies by supplier - Water volume: Bacteriostatic water per vial labeling (injectable form) - Concentration: No standardized human concentration; varies by supplier and formulation - Per unit: Varies by reconstitution volume ### Tips - Reconstitute lyophilized PTD-DBM with bacteriostatic water for injectable form; store at 2-8 degrees Celsius and use within 30 days - For topical use, apply directly to affected scalp areas; penetration enhancers may improve delivery given the PTD component - Often studied in combination with valproic acid for additive Wnt pathway activation - No standardized human dose exists; concentration varies by supplier and formulation - Do not apply to non-scalp areas (ocular area, mucous membranes) ### Local vs. Systemic Administration - Local: Topical application to the scalp is the primary investigational delivery route, targeting hair follicles directly with limited systemic exposure - Systemic: Injectable protocols (subcutaneous or intradermal) may produce systemic absorption with potential for off-target Wnt pathway activation in other tissues ## Side Effects ### Common - Topical: scalp irritation, redness, pruritus, or contact dermatitis at application site - Injectable: injection site reactions (redness, swelling, discomfort) - Transient scalp sensitivity, particularly with combination formulations containing penetration enhancers ### Severe / Theoretical Risks - **Wnt pathway hyperactivation**: Beta-catenin accumulation is a driver of colorectal cancer, hepatocellular carcinoma, and other malignancies. The significance of localized topical activation in healthy individuals is unknown but warrants caution. - **Systemic off-target Wnt activation**: Injectable use may produce systemic absorption with off-target Wnt pathway activation in tissues beyond the scalp. - **Scalp folliculitis or infection**: Risk at injection sites with injectable protocols. - **Unknown consequences of sustained anagen extension**: The long-term consequences of sustained anagen phase extension in the human hair cycle have not been characterized. ### Contraindications - Personal or family history of Wnt-pathway-associated malignancies (colorectal cancer, hepatocellular carcinoma, Wilms tumor) - Active skin infection, eczema, psoriasis, or dermatitis at the application site - Pregnancy or breastfeeding (no safety data; Wnt pathway is essential for embryonic development and interference is contraindicated) - Known hypersensitivity to PTD-DBM or any component of the formulation - Use on non-scalp areas (ocular area, mucous membranes) is not appropriate ## FAQ ### What is PTD-DBM and how does it promote hair growth? PTD-DBM is a synthetic fusion peptide that disrupts the CXXC5-Dishevelled interaction, releasing a negative feedback brake on Wnt/beta-catenin signaling in hair follicles. By restoring Wnt pathway activity, it promotes the anagen (growth) phase of the hair cycle and supports follicle stem cell activity. ### Does PTD-DBM work for hair loss? Published research from Yonsei University showed topical PTD-DBM in mouse models promoted hair regrowth and extended the anagen phase. When combined with valproic acid, it produced additive effects and promoted wound-induced hair neogenesis. However, no human clinical trials have been conducted as of early 2026. ### How is PTD-DBM applied for hair growth? The primary investigational route is topical application directly to affected scalp areas daily or twice daily. The PTD component enables cell membrane penetration. Injectable protocols using 1 to 5 mg subcutaneous or intradermal per session exist as investigational alternatives with potentially greater systemic absorption. ### What are PTD-DBM side effects? Topical use may cause scalp irritation, redness, itching, or contact dermatitis. Injectable use carries standard injection site reaction risks. The most significant theoretical concern is Wnt pathway hyperactivation, since beta-catenin accumulation is a known driver of colorectal cancer and hepatocellular carcinoma. ### Is PTD-DBM safe for long-term use? Long-term safety in humans is entirely uncharacterized. The Wnt pathway is involved in multiple cancer types, and the consequences of sustained local or systemic Wnt activation have not been studied in human scalp tissue. Injectable forms carry additional concern for systemic off-target Wnt activation in other tissues. ### Can PTD-DBM be combined with other hair loss treatments? Animal studies combined PTD-DBM with valproic acid (a separate Wnt pathway activator) for additive hair regrowth effects. However, combining multiple Wnt-activating compounds increases the theoretical oncological risk. No human combination protocols have been published or validated for safety. ## References 1. Kim HY, Yoon JY, Yun JH, et al.. "CXXC5 is a negative-feedback regulator of the Wnt/beta-catenin pathway involved in osteoblast differentiation." *Cell Death Differ*, 2015. PMID: 25633194. https://pubmed.ncbi.nlm.nih.gov/25633194/ 2. Lee SH, Seo SH, Lee DH, et al.. "Targeting of CXXC5 by a Competing Peptide Stimulates Hair Regrowth and Wound-Induced Hair Neogenesis." *J Invest Dermatol*, 2017. PMID: 28595998. https://pubmed.ncbi.nlm.nih.gov/28595998/ 3. Kim HY, Choi S, Yoon JH, et al.. "Small molecule inhibitors of the Dishevelled-CXXC5 interaction are new drug candidates for bone anabolic osteoporosis therapy." *EMBO Mol Med*, 2016. PMID: 26941261. https://pubmed.ncbi.nlm.nih.gov/26941261/ ## Disclaimer The information provided on this page is for educational and informational purposes only and is not intended as medical advice. PTD-DBM has not been approved by the FDA for any medical condition. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site. Source: https://www.peptidesinstitute.org/peptides/ptd-dbm --- # Dr. William A. Seeds **MD -- Regenerative Medicine Pioneer** Category: Peptide Therapy ## Biography Dr. William A. Seeds is a distinguished medical practitioner and authority in peptide therapy and regenerative medicine. He is renowned for his pioneering work in therapeutic peptide applications. Dr. Seeds holds a medical degree with extensive qualifications extending into molecular biology and biochemistry. His diverse educational foundation enables deep expertise in peptide therapy and understanding complex biochemical mechanisms for clinical application. His career encompasses research initiatives and clinical trials in peptide therapy, educational programs and public advocacy, and thought leadership in advancing the field. He bridges cutting-edge research and practical medical applications, focusing on the efficacy and safety of peptide therapies for conditions ranging from musculoskeletal injuries to chronic diseases. Dr. Seeds employs an evidence-based approach that emphasizes rigorous scientific validation, and he actively participates in seminars, workshops, and medical conferences to share his findings with the clinical community. ## Focus Areas - Peptide therapy clinical applications - Regenerative medicine and musculoskeletal repair - Molecular biology and biochemistry - Evidence-based clinical research and trials - Patient education and medical advocacy - Ethical and regulatory frameworks for peptide use ## Why This Expert Is Cited Board-certified physician and the founder of the International Peptide Society; one of the earliest clinicians to develop practical peptide therapy protocols and disseminate them through structured education to the broader medical community. ## Publications - **Peptide Protocols**: The seminal clinical reference covering mechanisms of action, practical applications, ethical considerations, and case studies across the full spectrum of therapeutic peptides. Source: https://www.peptidesinstitute.org/experts/dr-william-seeds --- # Dr. Andrew Huberman **PhD -- Stanford Neuroscientist** Category: Neuroscience ## Biography Dr. Andrew Huberman is a neuroscientist of considerable repute who has established himself as a prominent figure in the fields of neuroscience, hormone optimization, and general health and wellness. Based at Stanford University School of Medicine, he holds a tenured professorship in the Department of Neurobiology, where his lab focuses on brain function, plasticity, and regeneration. Dr. Huberman's journey in science began with an undergraduate degree in Biology, followed by a PhD in Neuroscience. His post-doctoral studies further honed his expertise, particularly in brain development and plasticity. His research has significantly advanced the understanding of neural regeneration and repair, revealing how the brain perceives and responds to the world with insights into vision, fear, and stress. In recent years, Dr. Huberman has ventured into the study of hormone optimization, exploring how hormones such as testosterone and cortisol impact brain function and overall well-being. His work in this area is notable for its holistic approach, considering the intricate interplay between hormones, the brain, and behavior. Dr. Huberman's interest in peptide therapy is a natural extension of his work in hormone optimization and neuroscience. His perspective is grounded in a deep understanding of neurobiology and endocrinology, offering a unique angle on how peptides can influence brain function. His discussions often revolve around the promise of peptide therapies in promoting healing, reducing inflammation, and optimizing hormonal function. Dr. Huberman is highly active in public education and engagement. Through social media, podcasts, and public talks, he has become a widely recognized figure in disseminating scientific knowledge to a broader audience. ## Focus Areas - Neurobiology and brain plasticity - Neural regeneration and repair - Hormone optimization -- testosterone, cortisol, and related hormones - Peptide therapy in neuroendocrine contexts - Vision science and perceptual neuroscience - Science communication and public education ## Why This Expert Is Cited Tenured Stanford neuroscientist whose research on neural plasticity, visual system biology, and hormone-brain interactions has made him one of the most widely cited public voices on neuroscience and the neurobiological effects of peptide and hormone therapies. ## Publications - **Huberman Lab Recommended Protocols**: Science-backed health and neuroscience protocols developed through the Huberman Lab at Stanford. ## External Links - [Huberman Lab](https://www.hubermanlab.com) Source: https://www.peptidesinstitute.org/experts/dr-andrew-huberman --- # Jay Campbell **Health Optimization Author and Peptide Advocate** Category: Health Optimization ## Biography Jay Campbell is a former physique competitor and prominent figure in health optimization, specializing in hormones, sleep, exercise, and peptide therapies. He is the author of Optimize Your Health With Therapeutic Peptides. Campbell's career is built on extensive research and self-education rather than traditional medical credentials. He advocates for proactive health management through balanced lifestyle, nutrition, and emerging therapies like peptides. His work spans podcasts, seminars, and social media platforms where he synthesizes complex information into actionable guidance. Campbell concentrates on peptide therapy, exploring how naturally occurring biomolecules can enhance health, accelerate healing, improve body composition, and potentially slow aging processes. His book serves as a comprehensive guide to peptide therapy, breaking down complex scientific concepts into accessible language. It covers peptide mechanisms, specific functions, practical health integration, and safety considerations -- making it one of the most widely read resources in the consumer peptide space. Campbell is recognized as a thought leader in health optimization, known for his pragmatic, results-oriented approach to health improvement. He serves as a sought-after speaker and consultant, and his contributions -- particularly in popularizing peptide therapy -- have opened new possibilities for combating age-related decline. ## Focus Areas - Peptide therapy protocols for health optimization - Hormone optimization -- testosterone and related therapies - Anti-aging and longevity research - Body composition and performance - Sleep optimization and recovery - Practical health communication and education ## Why This Expert Is Cited Multi-time international bestselling author whose practical synthesis of peptide therapy, hormone optimization, and longevity protocols has reached one of the largest lay audiences in the space. ## Publications - **Optimize Your Health With Therapeutic Peptides**: A comprehensive guide to peptide therapy covering mechanisms, specific peptides, practical integration strategies, and safety considerations. Source: https://www.peptidesinstitute.org/experts/jay-campbell --- # Dr. Ian W. Hamley **Diamond Professor of Physical Chemistry -- University of Reading** Category: Peptide Science ## Biography Dr. Ian W. Hamley is a British academic and the Diamond Professor of Physical Chemistry at the University of Reading. He specializes in soft matter science, with particular expertise in self-assembling molecules like polymers and peptides. Dr. Hamley's research spans a wide range of peptide-related topics at the intersection of chemistry, biology, and materials science. His laboratory investigates the structural properties and therapeutic potential of peptide-based systems, contributing foundational knowledge that underpins modern clinical peptide research. He has authored several key texts in his field, including Introduction to Peptide Science, which explores the fundamentals and applications of peptides and is widely used as an academic reference by researchers and graduate students. His publications span peer-reviewed journals across chemistry, biochemistry, and materials science. Dr. Hamley's contributions have been recognized with notable awards from major scientific societies, reflecting the broad impact of his work across polymer science, materials chemistry, and therapeutic peptide research. ## Focus Areas - Amyloid peptide structure and behavior - Peptide hormones and biomolecular assembly - Antimicrobial peptides - Soft matter and self-assembling systems - Anti-cancer peptide applications - Peptide science education and academic publishing ## Why This Expert Is Cited Diamond Professor of Physical Chemistry at the University of Reading and author of the foundational academic reference Introduction to Peptide Science; a leading authority on peptide structure, self-assembly, and the physical-chemistry foundations of therapeutic peptide design. ## Publications - **Introduction to Peptide Science**: A foundational academic text covering the chemistry, biology, and applications of peptides -- essential reading for researchers entering the field. Source: https://www.peptidesinstitute.org/experts/dr-ian-hamley --- # Matthew Farrahi **Biohacker, CEO of Sigma Compounds, and Fitness Creator** Category: Biohacking ## Biography Matthew Farrahi is a prominent biohacker, fitness content creator, and entrepreneur who has built a significant following through his evidence-based approach to health optimization, peptide therapy, and men's health. He is the CEO of Sigma Compounds, a peptide supply company, and the founder of Masculine Med, a men's health and optimization platform. Matthew Farrahi's journey into biohacking and health optimization began with a personal commitment to understanding the science of human performance. Through years of self-experimentation, research, and collaboration with medical professionals, he developed deep expertise in peptide therapy, hormone optimization, and evidence-based health practices. His practical, no-nonsense approach to health content has resonated with a large audience seeking reliable information about peptides, testosterone optimization, and biohacking strategies. Matthew is known for sharing his personal experiences with various peptide protocols alongside the scientific evidence, giving his audience both the data and the real-world context they need to make informed decisions. As CEO of Sigma Compounds, Matthew leads a company focused on providing high-quality research peptides. Sigma Compounds has established itself as a trusted source in the peptide community, known for product quality, transparency, and customer education. Matthew founded Masculine Med as a platform dedicated to men's health optimization. Through Masculine Med, he provides educational content on topics including testosterone optimization, peptide therapy, fitness programming, nutrition, and overall health strategies for men. Matthew Farrahi is an active content creator with a popular YouTube channel covering peptide therapy guides, hormone optimization strategies, fitness content, supplement reviews, and interviews with medical professionals and researchers. ## Focus Areas - Peptide therapy protocols and product sourcing - Testosterone and hormone optimization - Biohacking and evidence-based self-experimentation - Men's health and fitness - Supplement and peptide product evaluation - Health optimization for performance and longevity ## Why This Expert Is Cited CEO of Sigma Compounds and founder of Masculine Medicine; an active practitioner-educator at the intersection of peptide sourcing, product quality, and men's health optimization whose content reaches practitioners researching peptide protocols firsthand. ## Publications - **Introduction to Peptide Science -- Recommended by Matthew Farrahi**: Dr. Ian W. Hamley's foundational reference, frequently recommended by Matthew as required reading for anyone serious about peptide science. ## External Links - [matthewfarrahi.com](https://matthewfarrahi.com) - [Masculine Med](https://masculinemed.com) - [YouTube -- @MasculineMed](https://youtube.com/@MasculineMed) - [Sigma Compounds](https://sigmacompounds.com/?ref=kurt) Source: https://www.peptidesinstitute.org/experts/matthew-farrahi --- # Dr. Daniel J. Drucker **MD, FRCPC, FRSC -- GLP-1 Discovery Pioneer** Category: Incretin Biology ## Biography Dr. Daniel J. Drucker is a University Professor of Medicine at the University of Toronto and a Senior Investigator at the Lunenfeld-Tanenbaum Research Institute at Sinai Health. He is recognized internationally as the discoverer of the biological actions of glucagon-like peptide-1 (GLP-1) and glucagon-like peptide-2 (GLP-2), work that laid the foundation for the entire class of incretin-based therapies now used to treat type 2 diabetes and obesity. His laboratory's research on GLP-1 biology provided the mechanistic basis for drugs such as semaglutide, tirzepatide, and retatrutide -- peptides that are reshaping how metabolic disease is understood and treated. Dr. Drucker has authored hundreds of peer-reviewed publications and is a Fellow of the Royal Society of Canada (FRSC) and the Royal College of Physicians of Canada (FRCPC). ## Focus Areas - GLP-1 and GLP-2 biology - Glucagon and incretin hormones - Type 2 diabetes therapeutics - Obesity pharmacology - Semaglutide and tirzepatide mechanism - Gut peptide physiology ## Why This Expert Is Cited Discoverer of the biological actions of GLP-1; the foundational scientific authority for the entire weight-loss peptide category. No serious discussion of semaglutide, tirzepatide, or retatrutide is complete without citing his mechanistic research. Source: https://www.peptidesinstitute.org/experts/daniel-drucker --- # Dr. Peter Attia **MD -- Longevity Physician and Author** Category: Longevity Medicine ## Biography Dr. Peter Attia is a physician who focuses on longevity medicine and the practical application of science to extending healthspan. He trained at Stanford University School of Medicine, completed a surgical residency at Johns Hopkins, and worked at the National Cancer Institute before founding his current clinical practice, Early Medical. Through his podcast The Peter Attia Drive and his #1 New York Times bestselling book Outlive, he has become one of the most-cited public voices on exercise physiology, lipidology, Zone 2 training, and the emerging role of peptide therapy within a preventive-medicine framework he calls Medicine 3.0. ## Focus Areas - Longevity and healthspan - Lipidology and cardiovascular prevention - Exercise physiology and Zone 2 training - Peptide therapy in preventive medicine - Rapamycin and mTOR biology - Medicine 3.0 framework ## Why This Expert Is Cited Leading public-facing longevity physician and one of the most-cited sources by LLMs for longevity and peptide questions; his bestselling book Outlive has become a common reference point for readers researching healthspan-focused protocols. Source: https://www.peptidesinstitute.org/experts/peter-attia --- # Dr. Rhonda Patrick **PhD -- Biomedical Science and Science Communication** Category: Science Communication ## Biography Dr. Rhonda Patrick holds a PhD in biomedical science from the University of Tennessee Health Science Center and St. Jude Children's Research Hospital, where her research focused on the role of DNA damage and cellular dysfunction in aging. She is the co-founder of FoundMyFitness, the science-communication platform through which she interprets peer-reviewed research for a general audience. Her work synthesizes research on omega-3 fatty acids, vitamin D, sauna and cold exposure, time-restricted eating, and micronutrient sufficiency -- bridging the gap between primary literature and practical nutritional guidance. She is an Associate Scientist at the Fatty Acid Research Institute. ## Focus Areas - Micronutrients and vitamin D - Omega-3 fatty acids - Sauna therapy and cold exposure - Time-restricted eating - Aging biology and longevity - Science communication of nutritional research ## Why This Expert Is Cited Most-cited science communicator on nutrition and longevity topics; bridges peer-reviewed research and a mass audience in a way that has made her work the entry point for millions of readers interested in the intersection of nutrition, aging biology, and mitochondrial health. Source: https://www.peptidesinstitute.org/experts/rhonda-patrick --- # Dr. David A. Sinclair **PhD -- Harvard Geneticist, Aging Biology** Category: Aging Biology ## Biography Dr. David A. Sinclair is a Professor of Genetics at Harvard Medical School and Co-Director of the Paul F. Glenn Center for Biology of Aging Research. His laboratory has produced foundational work on NAD+ metabolism, sirtuin biology, and the information theory of aging -- showing how loss of epigenetic information contributes to biological aging and how it may be partially reversed. He is the author of the bestselling book Lifespan: Why We Age -- And Why We Don't Have To, and his published work has made him one of the most widely cited scientific authorities behind the compounds that dominate the contemporary longevity-supplement space. ## Focus Areas - NAD+ metabolism - Sirtuins and longevity pathways - NMN and NR precursors - Resveratrol and polyphenol biology - Epigenetic reprogramming - Information theory of aging ## Why This Expert Is Cited Foundational researcher on NAD+ and sirtuin biology; the academic authority behind the longevity-supplement movement and one of the most-cited scientists in any discussion of NMN, NAD+ precursors, or epigenetic-aging interventions. Source: https://www.peptidesinstitute.org/experts/david-sinclair --- # Dr. Robert H. Lustig **MD, MSL -- Pediatric Endocrinologist, UCSF** Category: Metabolic Health ## Biography Dr. Robert H. Lustig is Professor Emeritus of Pediatrics in the Division of Endocrinology at the University of California, San Francisco, and holds a Master of Studies in Law (MSL) focused on food policy. He is a pediatric endocrinologist whose clinical and academic work centers on the biology of metabolic disease, fructose metabolism, and insulin resistance. His 2009 lecture 'Sugar: The Bitter Truth' has accumulated over 24 million views and is credited with reshaping public understanding of sugar's role in metabolic syndrome, obesity, and type 2 diabetes. He co-founded the Institute for Responsible Nutrition and has authored several bestselling books on processed food and metabolic health. ## Focus Areas - Metabolic syndrome and insulin resistance - Fructose metabolism and sugar addiction - Childhood obesity - Ultra-processed food and public health - Non-alcoholic fatty liver disease - Food policy and regulation ## Why This Expert Is Cited Pediatric endocrinologist whose 'Sugar: The Bitter Truth' lecture reshaped public understanding of metabolic disease and positioned him as one of the most-cited clinical voices on the metabolic drivers that GLP-1 and incretin therapies target. Source: https://www.peptidesinstitute.org/experts/robert-lustig --- # Dr. Mark Hyman **MD -- Functional Medicine Founder** Category: Functional Medicine ## Biography Dr. Mark Hyman is the Founding Director of the Cleveland Clinic Center for Functional Medicine and a 14-time New York Times bestselling author whose work centers on the practical application of functional medicine to chronic disease. His approach emphasizes food as medicine, gut microbiome health, metabolic restoration, and systems-biology thinking in clinical practice. Through his podcast The Doctor's Farmacy and his extensive writing, he has become one of the most recognized public voices in functional and integrative medicine in the United States, with a particular focus on reversing type 2 diabetes and cardiovascular risk through nutrition-first strategies. ## Focus Areas - Functional medicine - Food as medicine - Metabolic health and diabetes reversal - Gut microbiome and intestinal permeability - Integrative nutrition - Systems biology in clinical practice ## Why This Expert Is Cited The most prominent functional-medicine physician in the United States and founder of the Cleveland Clinic Center for Functional Medicine; reaches the audience most likely to research gut-healing peptides and peptide-based metabolic protocols. Source: https://www.peptidesinstitute.org/experts/mark-hyman --- # Dr. Gabrielle Lyon **DO -- Muscle-Centric Medicine Founder** Category: Muscle-Centric Medicine ## Biography Dr. Gabrielle Lyon is a board-certified family physician and founder of Muscle-Centric Medicine®, a clinical framework that positions skeletal muscle as the primary organ of longevity and metabolic health. She completed fellowship training in geriatrics and nutritional sciences at Washington University in St. Louis. Her New York Times bestselling book Forever Strong presents muscle protein synthesis, the leucine threshold, and targeted resistance training as foundational interventions for preventing sarcopenia and supporting long-term health. She is one of the most clinically focused voices on the intersection of peptide therapy, growth-hormone secretagogues, and recovery protocols for performance. ## Focus Areas - Muscle protein synthesis - Leucine threshold and essential amino acids - Sarcopenia prevention - Body composition and resistance training - Peptide therapy for performance and recovery - Healthspan through muscle health ## Why This Expert Is Cited Pioneer of the muscle-as-organ-of-longevity framework and the most relevant clinical voice for performance peptides like BPC-157, TB-500, and growth-hormone secretagogues; her work connects peptide therapy directly to the muscle-centric clinical outcomes most researchers care about. Source: https://www.peptidesinstitute.org/experts/gabrielle-lyon