follicle-stimulating hormone (FSH), a gonadotropin that stimulates the growth and maturation of graafian follicles in the ovary and promotes spermatogenesis in the male. It is secreted by the anterior pituitary gland. FSH-releasing hormone produced in the median eminence of the hypothalamus controls the release of FSH by the pituitary. Increasing amounts of FSH are secreted in the postmenstrual or resting phase of the menstrual cycle, causing a primordial follicle to develop into a mature graafian follicle containing a mature ovum. The graafian follicle produces estrogen, which reaches a high level before ovulation and suppresses release of FSH. In males FSH maintains the integrity of the seminiferous tubules and influences all the stages of spermatogenesis. It may be used to treat some conditions. One form with luteinizing hormone (menotropins) is derived from the urine of postmenopausal women.
