Although it is clear that loss of ovarian function plays a major role in the menopause in women, there is evidence from animal studies that primary age-related hypothalamic and pituitary changes may also contribute to reproductive aging. Complete cessation of ovarian function results in the loss of negative feedback of ovarian steroids and inhibin on the hypothalamic and pituitary components of the reproductive axis. An increase in serum levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) occurs in postmenopausal women with removal of negative ovarian feedback. However, levels of LH and FSH after menopause decline steadily as a function of age in most though not all studies.