Effects of estrogen-progestin replacement therapy on plasma beta-endorphin levels in menopausal women

Serum beta-endorphin, LH, FSH, estradiol (E2) and progesterone (P) were measured in postmenopausal women before and after four different estrogen-progestin replacement therapies. Our result showed that serum E2 increased significantly and serum LH and FSH decreased significantly after all treatments. Serum P levels were similar before and after all treatments. Serum beta-endorphin levels increased significantly after cyclic administration of estrogen-progestin, but not after continuous administration of E2. We conclude that the frequently observed beneficial effects of estrogen-progestin replacement therapy on behavior and mood in postmenopausal women may be related to changes in peripheral opioid levels.