Gonadorelin is the synthetic form of native gonadotropin-releasing hormone (GnRH, also called LHRH), the decapeptide secreted by hypothalamic neurons that drives the pituitary–gonadal axis.1 Unlike most peptides catalogued here, it has a documented clinical and regulatory record: it was formerly approved as a diagnostic agent (Factrel) for assessing pituitary gonadotrope function and, as the acetate salt delivered by pulsatile pump (Lutrepulse), for inducing ovulation in hypothalamic amenorrhea.23 Both branded products have since been commercially withdrawn, and no GnRH product approved as “gonadorelin” is currently marketed in the United States.4 Because its biological effect depends entirely on the pattern of exposure — pulsatile delivery stimulates the axis while continuous exposure desensitizes it — older literature must be read in that context. Material supplied for laboratory use is sold strictly for research use only and is not a drug; the information below summarizes published findings and is not a direction for use.
Sequence & identity
A linear decapeptide with an N-terminal pyroglutamate and a C-terminal glycinamide. Identity confirmed against PubChem CID 638793 (InChIKey XLXSAKKOAKORKW-AQJXLSMYSA-N).1
Mechanisms studied
Gonadorelin binds the GnRH receptor (GnRHR), a Gq/11-coupled G-protein-coupled receptor on anterior-pituitary gonadotroph cells. Receptor activation stimulates phospholipase C, which cleaves PIP2 into IP3 and diacylglycerol, mobilizing intracellular calcium and activating protein kinase C; the downstream result is synthesis and secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).5 The response is frequency-dependent: in published work, faster pulses favoured LH and slower pulses favoured FSH, whereas continuous (non-pulsatile) exposure caused receptor downregulation and suppression of gonadotropin output — the basis on which long-acting GnRH agonists are used to suppress the axis.5
Dosing in the research literature
The figures below summarise regimens as reported in published research — they are not recommendations or directions for use.
| Source / model | Regimen reported | Notes |
|---|---|---|
| Factrel (gonadorelin HCl) product labeling — diagnostic use | A single 100 mcg dose was administered subcutaneously or intravenously, with serum LH measured at timed intervals to evaluate pituitary gonadotrope capacity. | Reported as a diagnostic test of pituitary reserve, not a therapeutic regimen. Product since commercially withdrawn.2 |
| Lutrepulse (gonadorelin acetate) labeling — ovulation induction in hypothalamic amenorrhea | A starting dose of 5 mcg every 90 minutes was delivered subcutaneously via a programmable pulsatile pump (Lutrepulse delivery device), with stepwise upward adjustment after 21-day intervals if no response. | Pulsatile pump delivery was integral to efficacy; the same molecule given continuously would suppress rather than stimulate. Product since commercially withdrawn.3 |
| Filicori et al., pulsatile GnRH clinical series (Lutrepulse for injection) | Intravenous pulsatile GnRH studied across a cohort of women with primary and secondary hypothalamic amenorrhea, with ovulation reported in the large majority of treated cycles. | Illustrative of historical clinical use of pulsatile delivery; reported, not a recommendation.6 |
Effects observed in research
In published human studies, pulsatile gonadorelin reproduced physiologic hypothalamic input: a single diagnostic dose produced a measurable rise in serum LH (and a smaller FSH rise) used to gauge pituitary reserve,2 and pump-delivered pulsatile dosing restored gonadotropin secretion and ovulation in women with hypothalamic amenorrhea, with monofollicular ovulation reported in most treated cycles.36 Reported adverse effects in the labeled products were generally mild and included injection-site reactions; rare hypersensitivity reactions were noted with repeated administration.2 Outcomes for non-clinical or off-label use have not been established.
Strength of evidence
Grade B. Gonadorelin is one of the better-documented peptides in this catalogue: native GnRH has a well-characterized receptor and signaling mechanism,5 and the drug carried FDA-approved diagnostic and fertility indications supported by labeled clinical data and clinical series.236 It is not assigned Grade A here because the approved products have been commercially withdrawn, contemporary use is largely off-label or compounded, and rigorous modern trials for newer indications are limited. Evidence quality should not be confused with availability: there is no GnRH product currently approved as gonadorelin in the United States.4
Reconstitution & storage
Reconstitute with bacteriostatic water for laboratory handling. Store lyophilised material frozen and reconstituted material refrigerated. Use Peptigo’s reconstitution calculator and storage cheat sheet for working figures.
References
- PubChem Compound Summary for CID 638793, Gonadorelin. National Center for Biotechnology Information, U.S. National Library of Medicine. pubchem.ncbi.nlm.nih.gov/compound/638793
- Factrel (gonadorelin hydrochloride) for injection — prescribing information; product monograph summary, RxList. www.rxlist.com/factrel-drug.htm
- Lutrepulse (gonadorelin acetate for injection) — product monograph, including pulsatile pump delivery and dosing in hypothalamic amenorrhea. Ferring / RxMed monograph.
- Gonadorelin regulatory status: Factrel and Lutrepulse commercially withdrawn; no FDA-approved gonadorelin product currently marketed in the U.S. (FDA drug status / labeling records).
- Casteel CO, Singh G. Physiology, Gonadotropin-Releasing Hormone. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. NCBI Bookshelf NBK558992.
- Filicori M, et al. Efficacy and safety of intravenous pulsatile gonadotropin-releasing hormone: Lutrepulse for injection. (Clinical series in hypothalamic amenorrhea.) PubMed PMID 2122733.