Gonadorelin (GnRH)
Also known as: GnRH, Gonadotropin-Releasing Hormone, LHRH, Factrel
Overview
Gonadorelin is the synthetic form of naturally occurring gonadotropin-releasing hormone (GnRH/LHRH), a decapeptide produced by hypothalamic neurons and released in a pulsatile fashion to stimulate pituitary LH and FSH secretion. When administered in a physiologically pulsatile pattern, gonadorelin restores normal gonadotropin secretion in hypothalamic hypogonadism. Used diagnostically to assess pituitary LH/FSH reserve and therapeutically in pulsatile pump delivery for hypothalamic amenorrhea and male infertility. Continuous administration (like GnRH agonists) causes receptor downregulation.
Mechanism of Action
Gonadorelin binds GnRH receptor (GnRHR), a Gq/11-coupled GPCR on pituitary gonadotroph cells. Pulsatile GnRH activates phospholipase C, generating IP3-mediated calcium release and PKC activation, which stimulates synthesis and release of both LH and FSH. The pulsatile pattern is critical: the GnRHR requires episodic stimulation (approximately every 60-90 minutes for optimal LH/FSH release in females; every 90-180 minutes in males). Continuous exposure causes receptor internalization and downregulation—the mechanism exploited by GnRH agonists like leuprolide for medical castration.
Potential Benefits
- Restoration of physiological LH/FSH secretion in hypothalamic hypogonadism
- Diagnostic test for pituitary gonadotroph reserve
- Treatment of hypothalamic amenorrhea and idiopathic hypogonadotropic hypogonadism
- Male infertility treatment preserving spermatogenesis (unlike GnRH agonists)
- Ovulation induction in anovulatory females
Dosage Protocols
The following reflects doses used in published research studies. This is not medical advice. Consult a qualified healthcare professional.
| Beginner | Diagnostic 100 mcg SC single dose (LH/FSH stimulation test) |
| Intermediate | Pulsatile pump for hypogonadotropic hypogonadism — clinician-directed |
| Advanced | Pulsatile ovulation induction — reproductive medicine only |
| Cycle Duration | Pulsatile: ovulation induction or puberty induction cycles |
FDA-approved (Factrel, Lutrepulse — now largely discontinued in U.S.). Still used internationally. Distinct from GnRH agonists (leuprolide) which cause desensitization.
Use our Reconstitution Calculator to determine exact syringe units for your protocol.
Routes of Administration
Subcutaneous Injection High
Diagnostic bolus route.
Intravenous Pulsatile (pump) 100%
Clinical pulsatile therapy via programmable pump — mimics endogenous GnRH pulses.
Read our full Routes of Administration Guide for detailed comparison of all delivery methods.
Stacking Protocols
Popular research stacks involving Gonadorelin (GnRH):
TRT Adjunct (off-label community use)
Community/TRT clinic use: gonadorelin 100-200 mcg 2-3x weekly (as a substitute for hCG) to maintain testicular function on TRT. Not FDA-approved for this indication.
Explore our complete Peptide Stacking Guide for more combinations and safety considerations.
Reconstitution
| Storage | Refrigerate at 2-8°C after reconstitution. Do not freeze reconstituted solution. |
|---|
Typical vial sizes: 100-500 mcg. Add bac water slowly down the side of the vial, swirl gently — do not shake. Use insulin syringe for precise dosing.
Need exact syringe measurements?
Amino Acid Sequence
pyroGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2
Side Effects & Safety
- Flushing, nausea (acute injection)
- Multiple gestation risk with ovulation induction
- Injection site reactions (pump therapy)
- OHSS risk in ovulation induction protocols
Safety & Contraindications
This information is for educational purposes only. Consult a qualified healthcare provider before using any peptide.
Hormone-Sensitive Cancers
Pregnancy / Lactation
Bleeding Disorders
Active Skin Infection at Injection Site
FDA Safety Information
FDA labeling notes hypersensitivity reactions; generally well-tolerated at diagnostic doses.
Pharmacokinetics
| Half-Life | ~2-4 minutes |
|---|---|
| Storage | Store lyophilized peptide at -20°C (long-term) or 2-8°C (short-term, under 30 days). Reconstituted: refrigerate at 2-8°C and use within 28-30 days. Protect from light. Do not freeze reconstituted solution. |
Synergistic Compounds
The following compounds have been studied alongside Gonadorelin (GnRH) for potential complementary or synergistic effects:
Learn More
References & Further Reading
Latest News & Research
View all articles →
FDA PCAC July 2026: What the BPC-157 peptide compounding review really means
FDA’s Pharmacy Compounding Advisory Committee will review seven unapproved peptides in July 2026. What that process means for BPC-157—and what it doesn’t.
FDA signals enforcement against unapproved compounded GLP-1 drugs: what it means for peptide medicine
The FDA says it will restrict GLP-1 APIs used in mass-marketed unapproved compounded drugs and crack down on advertising that calls them generic versions of branded drugs.
Sublingual compounded peptides: Quicksome claims and what the FDA’s July 2026 PCAC review could change
A press release claims needle-free, sublingual delivery for popular compounded peptides—just as the FDA's PCAC prepares a July 2026 review of seven peptides.
Pemvidutide IMPACT 48-Week MASH Data Lands At EASL 2026 Ahead Of Phase 3
Altimmune's pemvidutide hit 32.4% ELF response, 23.7% triglyceride drop, and 54.5% qFibrosis regression in 212-patient F2/F3 MASH IMPACT Phase 2b at EASL 2026.