HCG
Human chorionic gonadotropin (hCG) is an FDA-approved hormone (e.g., Novarel, Pregnyl, Ovidrel) indicated for inducing ovulation in anovulatory infertile women, treating selected cases of male hypogonadotropic hypogonadism, and prepubertal cryptorchidism not due to anatomic obstruction, while its use to support fertility or testicular function during testosterone replacement therapy is a common off-label application.
This page is a research-orientation summary, not a dosing guide. For anything beyond general background, read the primary literature or talk to a qualified clinician — specifics like amount, frequency, or administration aren't something we publish here.
What it does & how it works
hCG is a glycoprotein hormone that shares a common alpha subunit with LH, FSH, and TSH but has a unique beta subunit that confers its biological specificity. It binds the LH/hCG receptor, a G-protein-coupled receptor on ovarian theca/granulosa cells and testicular Leydig cells, activating cAMP/PKA signaling that mimics the action of endogenous LH. In women this triggers final follicular maturation and ovulation; in men it stimulates Leydig cell testosterone production and supports intratesticular conditions needed for spermatogenesis.
Typical results seen in research
As an approved fertility treatment, hCG administration triggers ovulation in properly selected anovulatory women undergoing ovulation induction and can stimulate testicular descent in prepubertal cryptorchidism or testosterone production in male hypogonadotropic hypogonadism. In off-label use alongside testosterone replacement therapy, hCG has been shown in retrospective and small clinical studies to help preserve testicular size and spermatogenic function that would otherwise be suppressed by exogenous testosterone. Response depends on the underlying cause of hypogonadism and is not effective in primary (testicular) failure.
How it’s commonly used
hCG is administered by intramuscular or subcutaneous injection, typically as a reconstituted powder, either in a clinical fertility-treatment setting with monitoring or, in off-label hormone-support protocols, via self-administered subcutaneous injection alongside other therapies.
- Global Pediatric Health · 2020 Testosterone versus hCG in Hypogonadotropic Hypogonadism - Comparing Clinical Effects and Evaluating Current Practice
- F&S Reports · 2025 Efficacy of human chorionic gonadotropin hormone in restoring spermatogenesis in men using non-prescribed androgens: a retrospective analysis of real-world data
- European Journal of Endocrinology · 1998 Pulsatile GnRH or human chorionic gonadotropin/human menopausal gonadotropin as effective treatment for men with hypogonadotropic hypogonadism: a review of 42 cases
Curated from published literature for research orientation. Not an exhaustive review, and not a substitute for reading primary sources.