Gonadorelin
FDA ApprovedAlso known as: GnRH, Gonadotropin-Releasing Hormone, Factrel, Lutrelef
Hormonal & ReproductiveLast reviewed: April 28, 2026
A synthetic form of the naturally occurring gonadotropin-releasing hormone (GnRH). Used clinically to evaluate pituitary function and increasingly prescribed in peptide therapy to maintain endogenous testosterone production during TRT or peptide cycles. Acts on the pituitary to stimulate LH and FSH release.
Mechanism of Action
Binds to GnRH receptors on gonadotroph cells in the anterior pituitary, triggering pulsatile release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). This maintains the HPG axis feedback loop and preserves testicular function, including spermatogenesis.
Common Uses
- Maintaining fertility during TRT
- Pituitary function testing
- Hypothalamic amenorrhea treatment
- Post-cycle therapy (PCT)
- Preserving testicular size during hormone therapy
Known Risks
- Injection site reactions
- Headache and nausea
- Flushing
- Potential for desensitization with continuous (non-pulsatile) use
- Allergic reactions (rare)
Regulatory Status
FDA-approved as Factrel for diagnostic evaluation of pituitary gonadotroph function. Lutrelef (pulsatile gonadorelin) approved in 2024 for hypothalamic amenorrhea. Widely compounded for off-label use in fertility preservation during TRT.
Common Protocols
Protocol information is for educational reference only. Dosing varies significantly by individual, condition, and physician guidance. Always work with a licensed healthcare provider.
Subcutaneous injection
Typical Dose
100–200 mcg
Frequency
Every other day or twice weekly
Cycle Length
Ongoing (concurrent with TRT)
Pulsatile administration is key — continuous exposure causes receptor desensitization (opposite effect). Most compounding pharmacies provide pre-mixed vials. Often paired with TRT to maintain fertility and testicular volume.
Related Compounds
Research References
This information is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any peptide therapy. Data is compiled from published research and regulatory sources and may not reflect the most recent developments.