Progestogens, similarly to the androgens and estrogens through their own respective receptors, inhibit the secretion of the gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH) via activation of the PR in the pituitary gland. This effect is a form of negative feedback on the hypothalamic–pituitary–gonadal axis (HPG axis) and takes advantage of the mechanism that the body uses to prevent sex hormone levels from becoming too high. Accordingly, progestogens, both endogenous and exogenous (i.e., progestins), have antigonadotropic effects, and progestogens in sufficiently high amounts can markedly suppress the body's normal production of progestogens, androgens, and estrogens as well as inhibit fertility (ovulation in women and spermatogenesis in men).