HCG
Also sold as Human Chorionic Gonadotropin, Pregnyl.
- Half-life
- 33 h
- Steady state
- ~7 d
- Class
- Fertility / TRT
- Category
- TRT
Published population averages. Steady state is the usual five half-life rule of thumb, not a measurement. See peptide half-life, explained.
Overview
Human Chorionic Gonadotropin (HCG) is a glycoprotein hormone naturally produced during pregnancy. In male health, it mimics luteinizing hormone (LH) to maintain testicular function during TRT. It preserves intratesticular testosterone production, fertility potential, and testicular size that would otherwise decline during exogenous testosterone use.
How it works
Binds and activates LH/CG receptors on Leydig cells in the testes, stimulating intratesticular testosterone production and maintaining spermatogenesis. Also supports estrogen production via aromatase in Leydig and Sertoli cells. In females, triggers ovulation by mimicking the LH surge.
Half-life and peak
Biphasic elimination: initial phase ~11 hours, terminal phase ~23–33 hours. Peak serum levels reached 6–24 hours after intramuscular injection. Subcutaneous injection shows similar bioavailability. Typically dosed 2–3 times per week alongside TRT.
What it is studied for
Male fertility preservation during TRT, testicular atrophy prevention, hypogonadotropic hypogonadism, cryptorchidism, ovulation induction (female), weight loss protocols (debunked).
Research status
FDA-approved for multiple indications (Pregnyl, Novarel). Well-established safety profile. FDA restricted compounding pharmacies from producing HCG (2020), then reversed. Standard of care for fertility preservation during TRT.
Sources
- HCG for male fertility during TRT — Fertility and Sterility · pubmed.ncbi.nlm.nih.gov
- HCG monotherapy in hypogonadism — Andrologia · doi.org
- HCG pharmacokinetics review — Drug Metabolism Reviews · pubmed.ncbi.nlm.nih.gov
Educational reference only. This page describes what is published about a compound; it is not medical advice, not a recommendation to take anything, and not a dosing guide. Several compounds in this catalog are investigational and are not approved medicines. Talk to a doctor.