Scientific Reference

HCG (Human Chorionic Gonadotropin)

Evidence profile: Controlled human evidence

Human Chorionic Gonadotropin (HCG) is a heterodimeric glycoprotein hormone naturally produced by the placenta during pregnancy. It consists of an alpha subunit shared with other pituitary hormones (LH, FSH, TSH) and a unique beta subunit that confers its biological specificity. Pharmaceutical HCG is used in clinical and research settings to stimulate endogenous testosterone production in males, preserve fertility during testosterone replacement therapy (TRT), and induce ovulation in females. It acts as a luteinizing hormone (LH) analog, binding to LH receptors and activating steroidogenesis.

Mechanism of Action

HCG binds to luteinizing hormone (LH) receptors on Leydig cells in the testes, stimulating testosterone and estrogen synthesis. In females, it acts on ovarian theca and granulosa cells to trigger final oocyte maturation and ovulation. Its glycosylation structure extends circulation time, producing a half-life of approximately 24–36 hours with peak levels occurring 6–12 hours post-injection.

Molecular Information

Type: Heterodimeric glycoprotein hormone
Length: 237 amino acids

Published Research

Clomiphene citrate and human chorionic gonadotropin are both effective in restoring testosterone in hypogonadism: a short-course randomized study
Habous M et al. · BJU international · 2018 · Clinical
PMID 29772111 — View on PubMed
Late-onset hypogonadism: the advantages of treatment with human chorionic gonadotropin rather than testosterone
La Vignera S et al. · The aging male : the official journal of the International Society for the Study of the Aging Male · 2016 · Clinical
PMID 26488941 — View on PubMed
Gonadotropins for pubertal induction in males with hypogonadotropic hypogonadism: systematic review and meta-analysis
Alexander EC et al. · European journal of endocrinology · 2024 · Review
PMID 38128110 — View on PubMed
A combined analysis of data to identify predictive factors for spermatogenesis in men with hypogonadotropic hypogonadism treated with recombinant human follicle-stimulating hormone and human chorionic gonadotropin
Warne DW et al. · Fertility and sterility · 2009 · Review
PMID 18930225 — View on PubMed