hCG vs Relaxin

Glycoprotein hormone binding LH receptor on Leydig cells; stimulates testosterone production; prevents testicular atrophy during TRT; maintains spermatogenesis via FSH-like activity

The most widely used adjunct in testosterone replacement therapy. Maintains testicular size and function, preserves fertility, and stimulates endogenous testosterone production by mimicking LH.

Binds RXFP1 receptor, activating adenylyl cyclase and cAMP/PKA pathway. Upregulates matrix metalloproteinases (MMPs) to degrade excess collagen. Inhibits TGF-β fibrotic signaling. Promotes cervical softening and pelvic ligament compliance.

A peptide hormone produced by the corpus luteum during pregnancy and in small amounts in non-pregnant individuals. Remodels connective tissue, relaxes pelvic ligaments, and has potent anti-fibrotic effects. Studied for pelvic floor dysfunction, fertility support, and cardiac fibrosis.