HCG binds the same LH/CG receptors as luteinizing hormone, so Leydig cells respond by producing testosterone on their own. That makes it the standard model for studying how testicular function and fertility hold up during suppressive testosterone protocols, and in female physiology the standard ovulation trigger. It is a licensed biologic, not a research-grade novelty.
- Mimics LH at LH/CG receptors on Leydig cells, so testosterone production comes from the testes rather than an outside source.Coviello 2005
- Carries genuine FDA labeling: Pregnyl and Novarel are labeled for male hypogonadism.FDA labels (Pregnyl/Novarel)
- In female physiology it stands in for the LH surge, serving as ovulation trigger and luteal support.rxlist (Pregnyl monograph)
- Central research question is preserving intratesticular testosterone and fertility while an exogenous androgen suppresses the axis.Coviello 2005
- Fertility endpoints read out slowly: one full spermatogenesis cycle runs 70-plus days before semen analysis shifts.Complete Peptide Guide