REGULATORYRFK Jr.: 14 peptides returning to Category 1 — FDA advisory committee July 2026TRENDINGHexarelin: ↑↑ Surging ��� Trends score 100 as of May 2026UPDATESemaglutide and tirzepatide compounding ended — shortage resolved Feb/May 2025REGULATORYBPC-157, TB-500, thymosin alpha-1, CJC-1295, ipamorelin: expected Category 1 reclassification pendingEVENTpep-talk con ��� First US Peptide Convention · August 2026 · Anaheim CAFDAFDA advisory committee meetings scheduled: late July 2026REGULATORYRFK Jr.: 14 peptides returning to Category 1 — FDA advisory committee July 2026TRENDINGHexarelin: ↑↑ Surging ��� Trends score 100 as of May 2026UPDATESemaglutide and tirzepatide compounding ended — shortage resolved Feb/May 2025REGULATORYBPC-157, TB-500, thymosin alpha-1, CJC-1295, ipamorelin: expected Category 1 reclassification pendingEVENTpep-talk con ��� First US Peptide Convention · August 2026 · Anaheim CAFDAFDA advisory committee meetings scheduled: late July 2026

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Peptide Library

Gonadorelin

GnRH / LHRH / Factrel / Lutrepulse

Sexual Health

Gonadorelin is a synthetic form of gonadotropin-releasing hormone (GnRH), identical in structure to the endogenous hypothalamic decapeptide that controls reproductive hormone secretion. When administered in pulsatile fashion, it stimulates the anterior pituitary to release both luteinizing hormone (LH) and follicle-stimulating hormone (FSH). It is used clinically for diagnostic testing of pituitary function and therapeutically to maintain fertility during testosterone replacement therapy.

Mechanism of Action

Synthetic analog of endogenous gonadotropin-releasing hormone (GnRH). Pulsatile administration stimulates FSH and LH release from the anterior pituitary. Continuous administration paradoxically downregulates the HPG axis through receptor desensitization.

Research Protocols

For research purposes only. Not medical advice.

Pulsatile protocols use 25-100mcg subcutaneously every 90-120 minutes via pump to mimic natural GnRH pulses. Diagnostic test protocols use a single 100mcg IV dose. Continuous dosing protocols (suppressive) not commonly used with the native peptide.

Research Notes

Clinical Research Status

Gonadorelin has FDA approval as a diagnostic agent (Factrel) for evaluating pituitary gonadotroph function and in pulsatile form (Lutrepulse) for hypothalamic amenorrhea, though the latter formulation has been discontinued. It is increasingly prescribed off-label by TRT clinics as an alternative to HCG for maintaining LH/FSH secretion and testicular function. Current research focuses on its role in preserving spermatogenesis during exogenous testosterone administration.

Key Published Findings

Pulsatile GnRH administration has been demonstrated to restore ovulation in women with hypothalamic amenorrhea with pregnancy rates of 20-30% per cycle. In male patients on TRT, subcutaneous gonadorelin at doses of 100-400 mcg administered two to three times daily can maintain measurable LH and FSH levels. The pulsatile pattern is critical as continuous administration paradoxically suppresses gonadotropin release through receptor downregulation.

Safety Profile

Gonadorelin has an excellent safety profile with minimal systemic side effects when used at appropriate doses. Injection site reactions are the most commonly reported adverse event. Headache, flushing, and abdominal discomfort occur rarely. The main clinical concern is ensuring pulsatile rather than continuous dosing patterns to avoid the paradoxical suppressive effect seen with GnRH agonists.

Comparison to Related Compounds

Unlike HCG which directly stimulates Leydig cells, gonadorelin works upstream by stimulating the pituitary to release endogenous LH and FSH, maintaining more physiological hormonal signaling. Compared to GnRH agonists like leuprolide or triptorelin, gonadorelin at pulsatile doses stimulates rather than suppresses the reproductive axis. It offers a more physiological approach to fertility preservation during TRT but requires more frequent dosing than HCG.

Community Observations

Gonadorelin gained significant popularity after 2020 when compounded HCG became harder to obtain, with many TRT clinics switching patients to gonadorelin protocols. Practitioners note that effective use requires proper dosing frequency (typically twice daily subcutaneous injections) to mimic natural GnRH pulsatility. Some clinicians report that gonadorelin is less reliably effective than HCG for testicular size maintenance, though individual responses vary.

Half-Life

~2-4 minutes

Reconstitution

Bacteriostatic water (BAC)

Storage

Lyophilized

Refrigerate 2-8C up to 12 months.

Reconstituted

Refrigerate 2-8C. Use within 14 days.

US Legal Status

FDA-approved for diagnostic use (Rx only)

Also Known As

GnRHLHRHFactrelLutrepulse

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