HCG
Human Chorionic Gonadotropin
What is HCG?
Human Chorionic Gonadotropin (HCG) is a glycoprotein hormone naturally produced during pregnancy. In men, it acts as an LH (luteinizing hormone) analog, stimulating Leydig cells in the testes to produce testosterone and maintain testicular function. It is widely used alongside TRT to prevent testicular atrophy and preserve fertility.
HCG binds to LH receptors on testicular Leydig cells, stimulating endogenous testosterone production and maintaining intratesticular testosterone — essential for spermatogenesis. Because TRT suppresses LH from the pituitary, the testes stop receiving stimulation and atrophy. HCG replaces this LH signal, keeping the testes active even while exogenous testosterone is administered.
Research Evidence
Multiple RCTs demonstrate HCG co-administration with TRT maintains testicular volume, intratesticular testosterone, and sperm production significantly better than TRT alone.
HCG is first-line treatment for hypogonadotropic hypogonadism-related infertility with strong clinical trial evidence supporting fertility restoration.
In men with intact Leydig cell function, HCG reliably stimulates endogenous testosterone production and is used as monotherapy for some forms of hypogonadism.
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 |
|---|---|---|---|
| 5,000 IU | 5 ml | 1,000 IU/ml | 250 IU = 25 units |
| 10,000 IU | 10 ml | 1,000 IU/ml | 500 IU = 50 units |
Frequently Asked Questions
Should HCG be used with TRT?
Yes, if testicular atrophy prevention or fertility preservation is a priority. TRT alone suppresses LH, causing testes to atrophy over time. HCG maintains LH receptor stimulation, preserving testicular size and sperm production. Standard dose is 250-500 IU 2-3x weekly alongside testosterone.
What is the difference between HCG and Gonadorelin for TRT?
HCG acts directly on Leydig cells via LH receptors, bypassing the pituitary. Gonadorelin stimulates the pituitary to release LH and FSH naturally, preserving the full HPG axis. Both maintain testicular function on TRT, but Gonadorelin is more physiologic. HCG has decades of clinical safety data.
References
- [1]Coviello AD, Matsumoto AM, Bremner WJ, et al. Low-dose human chorionic gonadotropin maintains intratesticular testosterone in normal men with testosterone-induced gonadotropin suppression. J Clin Endocrinol Metab. 2005;90(5):2595-2602.
- [2]Ramasamy R, Scovell JM, Kovac JR, et al. Testosterone supplementation versus clomiphene citrate for hypogonadism. J Urol. 2014;192(3):875-879.
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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