Purity ≥98% (Contaminants: hTSH: 0.000027%; hLH: 0.000085 wt/wt). FSH is a gonadotropin and a glycoprotein having two subunits. The alpha subunit is similar to those of LH, HCG, and TSH. The beta subunit is different from the other hormones and confers its biochemical specificity. FSH is secreted by the basophilic cells of the anterior pituitary. FSH stimulates the growth and maturation of the ovarian follicles in the female and stimulates spermatogenesis in the male.