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What is Gonadorelin?
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) [2] 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.
Research Supply
Source high-purity Gonadorelin for your research
Dosage Guide
Route: Intravenous (IV) bolus or subcutaneous (SQ) injection; pulsatile SQ infusion pump for therapeutic use
Dosing 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
Injection Volumes
| Dose | Volume | Syringe Units |
|---|---|---|
| 50 mcg | 0.05 mL | 5 units |
| 100 mcg | 0.10 mL | 10 units |
| 250 mcg | 0.25 mL | 25 units |
Administration 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
Risks & Side Effects
Commonly Reported
Serious 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
Related Peptides
Experts Covering Gonadorelin
LEGAL 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.
Frequently Asked Questions
What is Gonadorelin and what is it used for?
How does Gonadorelin help during TRT?
What is the Gonadorelin dosage for TRT preservation?
What are Gonadorelin side effects?
How does Gonadorelin compare to HCG for TRT?
Is Gonadorelin FDA approved?
References
- 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
- Kim HK, Kee SJ, Seo JY, et al.. Gonadotropin-releasing hormone stimulation test for precocious puberty. Korean J Lab Med. 2011. PMID 22016677
- 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
Regulatory & Official Sources
- Gonadorelin — Wikipedia
- Factrel (gonadorelin) prescribing information — National Library of Medicine (DailyMed)