Agnus castus is obtained from the berries of the chaste tree. Constituents of agnus castus bind selectively to estrogen receptor beta. The beta receptor predominates in the heart, arteries, veins, bone and bladder. Agnus castus extracts also have agonistic effects at pituitary dopamine (D2) receptors when used in higher doses. This dopaminergic activity inhibits basal and thyrotropin-releasing hormone (TRH)-stimulated prolactin release. In women with hyperprolactinemia, chasteberry seems to suppress prolactin release. This may normalize luteal phase defects in the menstrual cycle. It’s thought that black cohosh might have selective estrogen receptor modulating (SERM) effects and therefore have estrogenic effects in some tissues and anti-estrogenic effects in other tissues. Preliminary research suggests that black cohosh might also act as a partial agonist at serotonin receptors which could also play a potential role in reducing menopausal symptoms. Preliminary clinical evidence also suggests that black cohosh might increase osteoblast activity by increasing levels of bone-specific alkaline phosphatase (bALP), which is a marker of bone formation. Ipriflavone enhances osteoblast function and inhibits bone resorption, mainly by inhibiting recruitment of osteoclasts. Preliminary evidence suggests that ipriflavone prevents bone density loss without suppressing the rate of bone formation. Ipriflavone has no direct estrogenic activity in postmenopausal women, but might potentiate the effects of estrogen on bone, increase the uterotropic activity of estrogen and stimulate estrogen-induced calcitonin secretion. Clinical evidence suggests that using ipriflavone in combination with conjugated estrogens for postmenopausal osteoporosis might allow for use of a lower estrogen dose. Vitamin D plays an important role in increasing the absorption of calcium and preventing osteoporosis.