HCG

Overview

HCG is a glycoprotein hormone naturally produced by the placenta during pregnancy that binds LH receptors to stimulate testosterone and estrogen biosynthesis. FDA-approved for cryptorchidism, hypogonadotropic hypogonadism, and ovulation induction.

Mechanism of action

Binds to LH receptors on Leydig cells in testes, stimulating testosterone production with a half-life of 24-36 hours, peak levels 6-12 hours post-injection, and 40-50% bioavailability via SubQ or IM routes.

Key research findings

• Maintains testicular function during TRT
• Preserves fertility and prevents testicular atrophy
• Stimulates endogenous testosterone production
• Induces ovulation in women
• FDA-approved for multiple indications
• Well-established safety profile

Research applications

Male Fertility

• TRT Adjunct — Maintains intratesticular testosterone at baseline during testosterone therapy, preventing atrophy and preserving fertility.
• Hypogonadotropic Hypogonadism — FDA-approved for secondary hypogonadism; combined with FSH for spermatogenesis induction.
• Post-Cycle Therapy — Restores testicular function after anabolic steroid cycles.

Female Fertility

• Ovulation Induction — FDA-approved trigger for follicular maturation; 15-25% pregnancy rate per cycle.

Pediatric

• Cryptorchidism — FDA-approved for prepubertal undescended testes not due to anatomical obstruction; ~25% success rate.