HomePeptides › Gonadorelin

Gonadorelin

GnRH, LHRH, Factrel

Tier 1 · FDA Approved
Class
GnRH agonist (native sequence)
Molecular target
GnRH receptor
Sequence / structure
pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2
Evidence tier
Tier 1 — FDA Approved
Category
Reproductive Axis

Biology & mechanism

The native hypothalamic decapeptide. Its defining property is that pulsatility determines the outcome: delivered in physiological pulses roughly every 90 minutes it stimulates LH and FSH release, whereas continuous exposure desensitises and downregulates the receptor and suppresses the axis entirely. That paradox is the basis of the entire GnRH agonist drug class — leuprolide and its relatives are used for chemical castration precisely by exploiting continuous exposure. Native gonadorelin has a half-life of only two to four minutes.

What the research actually shows

Long-established as a diagnostic agent for pituitary gonadotropin reserve, and historically used with pulsatile pumps to induce fertility in hypogonadotropic hypogonadism.

Regulatory status

FDA-approved historically as a diagnostic agent (Factrel); US availability has been limited and products discontinued. Now largely supplied through compounding, an area under active FDA scrutiny. Prohibited in sport (WADA S2 for males).

Safety signals

The pulsatility paradox is the practical hazard: administration patterns that are not genuinely pulsatile can suppress the axis rather than stimulate it — the opposite of the intended effect. Headache, flushing, injection-site reactions.

No usage guidance is published here

Forge Bioenergy does not publish dosing, reconstitution, or administration protocols for any peptide. See our editorial policy for why. If you are considering any substance on this page, that conversation belongs with a licensed physician.

References & further reading

Regulatory status changes. This page reflects our reading of public sources as of July 2026 and should be independently verified before it is relied upon.

Important notice Forge Bioenergy publishes scientific reference information only. Nothing on this site is medical advice, a therapeutic claim, or a recommendation to use any substance in humans. Many peptides described here are not approved by the FDA for any use, and several are approved only for narrow indications under prescription. We do not publish dosing, administration, or usage protocols. Consult a licensed physician before making any medical decision.