Gonadorelin
GnRH — Gonadotropin-Releasing Hormone
What is Gonadorelin?
Gonadorelin is synthetic GnRH — the hypothalamic signal that triggers the pituitary to release LH and FSH. In TRT protocols it is used as an alternative to HCG to maintain testicular function and fertility by preserving the natural hypothalamic-pituitary-gonadal (HPG) axis rather than bypassing it.
Gonadorelin stimulates the pituitary GnRH receptors, triggering natural LH and FSH release. Unlike HCG which directly stimulates Leydig cells, Gonadorelin keeps the entire HPG axis active — including FSH-driven spermatogenesis. Its extremely short half-life (2-4 minutes) requires pulsatile or frequent dosing to maintain stimulation.
Research Evidence
Long-established clinical use for diagnosing and treating hypothalamic hypogonadism. Pulsatile GnRH therapy restores full HPG axis function including fertility.
Clinical use alongside TRT shows preservation of testicular volume and sperm parameters. More physiologic than HCG due to maintaining full HPG axis signaling.
Increasing use in TRT clinics as HCG availability has become more restricted. Community data shows effective testicular maintenance at 100mcg 2-3x weekly SubQ.
Evidence grades: Gold = RCT human data · Silver = consistent animal/human data · Bronze = limited or preliminary
Dosing Protocols
Reconstitution Guide
| Vial Size | BAC Water | Concentration | Target draw |
|---|---|---|---|
| 2 mg | 2 ml | 1 mg/ml | 100mcg = 10 units |
| 5 mg | 5 ml | 1 mg/ml | 100mcg = 10 units |
Frequently Asked Questions
Is Gonadorelin better than HCG for TRT?
Both maintain testicular function on TRT. Gonadorelin is more physiologic — it preserves the full HPG axis including FSH production important for spermatogenesis. HCG bypasses the pituitary and only stimulates Leydig cells. For men prioritizing fertility and a natural hormonal pattern, Gonadorelin is preferred. For simplicity and established efficacy, HCG has decades of data.
Why does Gonadorelin require such frequent dosing?
Gonadorelin has a half-life of only 2-4 minutes — rapidly degraded by blood proteases. TRT adjunct protocols use 2-3x weekly SubQ to provide periodic stimulation rather than true pulsatile dosing. This is sufficient to maintain testicular function.
References
- [1]Sykiotis GP, Hoang XH, Avbelj M, et al. Congenital idiopathic hypogonadotropic hypogonadism: evidence of defects in the hypothalamus, pituitary, and testes. J Clin Endocrinol Metab. 2010;95(6):3019-3027.
- [2]Bhasin S, Cunningham GR, Hayes FJ, et al. Testosterone therapy in men with androgen deficiency syndromes. J Clin Endocrinol Metab. 2010;95(6):2536-2559.
This profile was prepared using AI-assisted research synthesis. Citations are provided where applicable — verify with primary sources before clinical application.
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