hCG (Human Chorionic Gonadotropin) Mechanism of Action
How hCG (Human Chorionic Gonadotropin) works: receptor targets, signalling pathways, and molecular profile.
Mimicking LH to Restart Testicular Function
hCG is structurally similar enough to LH (luteinizing hormone) that it binds and activates the same LH receptor on testicular Leydig cells, which respond by producing testosterone — the same signal the pituitary would normally send. This is why hCG can restore the body's own testosterone production even when the pituitary itself isn't sending that signal, whether due to a medical condition or exogenous testosterone therapy's suppressive feedback.
Preserving Fertility Alongside TRT
Because it directly stimulates the testes rather than relying on upstream pituitary signaling, hCG keeps spermatogenesis active during testosterone replacement therapy — a key reason it's the most established TRT-adjunct compound for men who want to preserve fertility while on exogenous testosterone.
References
- hCG monotherapy for hypogonadism · Madhusoodanan V, et al. · 2019