Ipriflavone (7-isopropoxyisoflavone), a non-hormonal isoflavone derivative, is currently used in several countries for prevention and treatment of postmenopausal osteoporosis. This compound is devoid of estrogenic activity in humans, but increases the activity of estrogens. Ipriflavone has been shown to be effective in reducing bone turnover rate mainly through an inhibition of bone resorption, and has been effect to stimulate of bone formation. Inhibitory effect of ipriflavone on bone resorption has been demonstrated both directly by the activation of mature osteoclast and the formation of new osteoclasts by stimulating estrogen-induced calcitonin secretion by thyroids in vivo. There are some evidence that ipriflavone has direct effect on bone formation. Several clinical studies have demonstrated that bone mineral density (BMD) was increased or maintained in patients treated with ipriflavone. Recently, a large multicentral study, Ipriflavone Multicenter European Fracture Study (IMEFS), was designed in order to investigate the efficacy of ipriflavone on the prevention of vertebral and the effect on BMD in women with postmenopausal osteoporosis.