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OtherPeptideEvidence B3 cited

Gonadorelin

Gonadotropin-Releasing Hormone

aka GnRH · LHRH · Factrel · gonadotropin releasing hormone

Synthetic GnRH that research shows stimulates pituitary release of LH and FSH, supporting reproductive hormone regulation.

Molecular wt
1182.3g/mol
Formula
C55H75N17O13
CAS
33515-09-2
Half-life
40 min
established
Tmax
30 min
Route
Subcutaneous injection
PubChem
638793

Sequence

One-letter10 residues

QHWSYGLRPG

Three-letter

pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2

Read this before quoting the sequence
Native human GnRH-I decapeptide. Residue 1 is 5-oxo-L-proline (pyroglutamate), written as Q in the FDA GSRS one-letter subunit; the C-terminus is a glycinamide, not a free acid. FDA GSRS subunit for GONADORELIN (UNII 9O7312W37G) is QHWSYGLRPG (10 residues); PubChem CID 638793 gives the three-letter form pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2.
Source ↗

Mechanism of action

Gonadorelin is a synthetic form of gonadotropin-releasing hormone (GnRH) that binds to GnRH receptors in the pituitary gland. This binding stimulates the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are crucial for the regulation of the reproductive system. LH and FSH promote the production of sex hormones such as testosterone and estrogen, supporting fertility and sexual function.

What the evidence actually shows

Grade B

There are several human clinical trials that demonstrate the efficacy of gonadorelin in stimulating LH and FSH release, supporting its use in fertility treatments. However, more research is needed to fully understand its long-term safety profile and effects in diverse populations.

Regulatory status

Status
Historically FDA-approved for human diagnostic/therapeutic use, but no human product is currently marketed in the US: Drugs@FDA lists FACTREL (NDA 018123, Hikma) and LUTREPULSE KIT (NDA 019687, Ferring) with marketing status 'Discontinued'. Gonadorelin products currently in DailyMed are veterinary (Fertagyl, Cystorelin, Factrel/Zoetis, OvaCyst, GONAbreed).
Approved as
Factrel (NDA 018123) and Lutrepulse Kit (NDA 019687) - both Discontinued in Drugs@FDA
Clinical stage
Previously approved; no current human marketing authorisation identified in Drugs@FDA.
WADA
Prohibited at all times (in- and out-of-competition), non-Specified. 2026 Prohibited List S2.2.1 'Testosterone-stimulating peptides in males' explicitly lists 'gonadotrophin-releasing hormone (GnRH, gonadorelin) and its agonist analogues'.
UK
prescription_only

In the UK, gonadorelin is classified as a prescription-only medication, used primarily for diagnostic purposes and fertility treatments.

Source ↗

Pharmacokinetics

Half-life
40 min
Tmax
30 min
Absorption
subcutaneous
Elimination
renal
Washout
1 days
Low-confidence pharmacokinetics
These figures are recorded as established rather than measured in a published PK study. Treat them as an order of magnitude. Anything downstream of them — accumulation, steady state, washout — inherits that uncertainty.

Dosing — what backs each figure

Human gonadorelin dosing was genuinely established and FDA-approved, but only as 90-minute pulsatile pump therapy (5-20 mcg/pulse, LUTREPULSE) for hypothalamic amenorrhoea, or as a single-dose pituitary LH-response diagnostic (FACTREL); both human NDAs are now discontinued and the only currently marketed FACTREL label is a cattle-only veterinary product. There is no approved or published human regimen resembling intermittent few-times-weekly self-injection.

ClinicalApproved labelling or a published human trial

  • 5 mcg per pulse every 90 minutes via the LUTREPULSE pulsatile pump; dose range 5-20 mcg/pulse/90 min; dosing interval may be changed to 120 min; recommended interval before dose adjustment is 21 days; continued until follicle maturation and ovulation, then through the late luteal phase to support corpus luteum function

    Women with primary hypothalamic amenorrhoea (deficient endogenous GnRH secretion), for induction of ovulation · pulsatile pump (subcutaneous per Ferring Canada product monograph; the US LUTREPULSE product was administered by intravenous pulsatile pump)

    LUTREPULSE (gonadorelin acetate for injection) product monograph, Ferring Canada, control no. 187199 ↗

  • Intravenous pulsatile gonadorelin acetate (LUTREPULSE for Injection) delivered by pump; multicentre trial in 109 women, ovulation in 91% (primary) and 96% (secondary hypothalamic amenorrhoea). Confirms the US-approved route was intravenous pulsatile administration

    109 women with primary or secondary hypothalamic amenorrhoea · intravenous (pulsatile pump)

    Santoro N. Efficacy and safety of intravenous pulsatile gonadotropin-releasing hormone: Lutrepulse for injection. Am J Obstet Gynecol. 1990;163(5 Pt 2):1759-64 ↗

  • Human gonadorelin products were FDA-approved but are ALL DISCONTINUED. Drugs@FDA/openFDA records: NDA018123 FACTREL (Hikma) injectable, strengths EQ 0.1 mg / 0.2 mg / 0.5 mg base per vial - marketing status Discontinued; NDA019687 LUTREPULSE KIT (Ferring) injectable, 0.8 mg/vial and 3.2 mg/vial - marketing status Discontinued. No human gonadorelin product is currently marketed in the US

    N/A - regulatory status record, not a dosing regimen · injection

    openFDA Drugs@FDA API query for gonadorelin / FACTREL / LUTREPULSE ↗

PreclinicalAnimal studies — not a human dose

  • FACTREL Injection (current DailyMed label is VETERINARY, cattle only, 'For use in animals only. Not for human use.'): 2 mL as a single intramuscular injection for ovarian follicular cysts; or 2-4 mL (100-200 mcg gonadorelin) IM per cow for oestrous synchronisation with LUTALYSE

    cattle (bovine) · intramuscular

Animal doses do not convert to human doses by body weight alone. Route matters too — a compound dosed intraperitoneally in mice tells you little about subcutaneous use.

Commonly circulatedNot established by any study
Dose
Clinical: microgram pulsatile or ~100 mcg doses
Frequency
2-3x weekly

Why this isn't evidence
The 'microgram pulsatile' phrase loosely echoes the real LUTREPULSE label (5-20 mcg/pulse) but the operative instruction '2-3x weekly' matches no documented human regimen - approved human gonadorelin dosing is either a pulse every 90 minutes by pump or a single diagnostic dose - and the '~100 mcg' figure corresponds to the veterinary cattle IM dose, so the ported figure is community TRT/PCT convention rather than sourced clinical dosing.

This figure is shown because it is what circulates and what people search for — not because it is supported. Cycle lengths in particular tend to be convention copied between compounds rather than anything derived from a compound's own pharmacokinetics.

Handling and storage

No compound-specific stability data exists
No human gonadorelin product is currently marketed in the US, so no current human prescribing information states storage requirements. The historic human products (Factrel, NDA 018123; Lutrepulse Kit, NDA 019687) are both listed as Discontinued in Drugs@FDA and their labels are no longer in DailyMed. The only gonadorelin labels currently in DailyMed are veterinary aqueous solutions; the Fertagyl (Merck Animal Health) label states: 'Keep refrigerated: 2-8 C (36-46 F). 20-mL vial: Use within 28 days of first puncture.' That figure applies to that veterinary solution formulation only and is not a human-product specification. No light-sensitivity or freeze-thaw statement was found in any gonadorelin label retrieved. General peptide handling still applies — reconstitute gently, keep it cold, keep it dark — but any specific figure you see quoted for this compound elsewhere is someone's assumption, not a measurement.
→ Reconstitution walkthrough→ Reconstitution calculator

Safety

Commonly reported
  • ·Headache
  • ·Nausea
  • ·"Abdominal discomfort"
Rarely reported
  • ·Allergic reactions
  • ·Anaphylaxis
Contraindications
  • ·Hypersensitivity to GnRH or GnRH analogs
  • ·Pregnancy
Drug interactions
  • ·Concurrent use with other hormone therapies may alter gonadorelin's effectiveness

Injection-site reactions, headache, flushing

Reported combinations

Reported as synergistic
  • ·Clomiphene, which may enhance fertility outcomes when used together
Reported as antagonistic
  • ·GnRH antagonists, which directly oppose the action of gonadorelin

Combination claims in this dataset are largely unsourced and should be treated as folk knowledge until a citation appears beside them.

References (3)

Data provenance

Chemistry and citations on this page were checked against primary sources on 2026-08-14. Values that could not be verified were left blank rather than filled with a plausible guess.

Could not verify
storage.lyophilized, storage.reconstituted, storage.lightSensitive, reconstitution.solvent

Research use only
This profile is educational reference material. It is not medical advice, not a prescription, and not an endorsement of self-administration. Compounds discussed here are research chemicals and most are not approved for human therapeutic use.

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