Gonadotropin-releasing hormone analog · Also known as GnRH, LHRH, Factrel, Lutrepulse
A synthetic version of the body's natural gonadotropin-releasing hormone (GnRH). It stimulates the pituitary gland to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are essential for reproductive function.
Gonadorelin was previously FDA-approved under the brand names Factrel (for diagnostic use) and Lutrepulse (for pulsatile infusion therapy). It was discontinued in the US for commercial reasons, not safety concerns. It is now commonly used off-label in hormone optimization and TRT clinics as an alternative to hCG for preserving fertility and testicular function.
Gonadorelin binds to GnRH receptors on gonadotroph cells in the anterior pituitary gland. When administered in a pulsatile fashion (mimicking the body's natural release pattern), it triggers the release of both LH and FSH. LH then stimulates testosterone production in the testes (Leydig cells), while FSH supports sperm production (Sertoli cells).
The critical challenge with gonadorelin is its extremely short half-life of 2-4 minutes. Natural GnRH is released in pulses every 60-120 minutes by the hypothalamus. True physiological replacement requires a pulsatile infusion pump, which is impractical outside clinical settings. Standard subcutaneous injections 2-3 times per week do produce acute LH surges, but the sustained stimulation seen with hCG (which has a 36-hour half-life) is difficult to replicate.
100 mcg 2-3x/week
Ongoing100-200 mcg 2-3x/week
Duration of TRT or as prescribedMost side effects tend to improve as your body adjusts.