Gonadotropins are hormones secreted by the pituitary gland that stimulate the activity of the gonads—the ovaries in women and the testes in men. The main gonadotropins are luteinizing hormone (LH) and follicle-stimulating hormone (FSH), both of which are critical for the regulation of the menstrual cycle, ovulation, and sperm production. Gonadotropin therapies are commonly used in fertility treatments.