FSH

Follicle-stimulating hormone (FSH) is a pituitary glycoprotein hormone built from a common alpha subunit (CGA) shared with LH, hCG and TSH and a hormone-specific beta subunit (FSHB) that determines its biological identity. Binding to the Gs-coupled FSH receptor triggers cAMP and PKA signaling. In females FSH drives granulosa cell proliferation, aromatase-mediated estrogen synthesis and follicular maturation; in males it sustains Sertoli cell function and spermatogenesis. Its secretion is governed by GnRH and restrained by ovarian inhibin and estradiol feedback. Recombinant FSH preparations are cornerstones of ovarian stimulation in assisted reproduction, and the FSH receptor is a therapeutic focus in infertility and oncology.