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CJC-1295 DAC

CJC-1295 DAC (Drug Affinity Complex)

Long-Acting GHRH Analog for Growth Hormone Support

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— authoritative voices whose published research informed this article

The information on this page is compiled from peer-reviewed research and is provided for educational and research purposes only. It is not medical advice, a diagnosis, or a treatment recommendation. Peptides discussed here may not be approved for human use in your jurisdiction. Always consult a qualified healthcare provider before starting, stopping, or modifying any health protocol.

Overview

What is CJC-1295 DAC?

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 [1]. 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 [2], 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.

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Protocol

Dosage Guide

Route: Subcutaneous injection, once weekly

Dosing Schedule

PeriodDose
Conservative research starting dose1 mg/week
Standard research protocol2 mg/week
Higher-end research protocols2-4 mg/week

Reconstitution

VIAL SIZE5 mg
WATER VOLUME2.5 mL bacteriostatic water
CONCENTRATION2 mg/mL
For a 2 mg weekly dose, draw 1 mL (100 units on a U-100 syringe)

Injection Volumes

DoseVolumeSyringe Units
1 mg0.5 mL50 units
2 mg1 mL100 units
4 mg2 mL200 units

Administration 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
Safety

Risks & Side Effects

Commonly Reported

Water retention and mild edema (hands, ankles, face): driven by elevated IGF-1 and GH activity on sodium and water handlingInjection site reactions: mild redness, swelling, or discomfort at the subcutaneous siteFatigue or somnolence: particularly in the days following injection during peak GH/IGF-1 elevationHeadacheTingling or numbness in hands or feet (carpal tunnel-like symptoms): associated with GH-driven fluid retention around nerve sheathsFlushing

Serious 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.

Related Research

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Expert Voices

Experts Covering CJC-1295 DAC

Dr. William A. Seeds

MD -- Regenerative Medicine Pioneer

Jay Campbell

Health Optimization Author and Peptide Advocate

Matthew Farrahi

Biohacker, CEO of Sigma Compounds, and Fitness Creator

Dr. Gabrielle Lyon

DO -- Muscle-Centric Medicine Founder

LEGAL 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.

Frequently Asked Questions

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 [2]. 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
  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
  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