The preventive and therapeutical measures to be implemented the post-menopausal osteoporosis are varied, although there is no clear, single protocol of intervention. ESTROGENS AND PROGESTOGENS: It si verify that the administration of estrogens and/or progestogens prevents bone loss with an action on mineral components of bone and on collagenic metabolism. BIPHOSPONATES: Operate inhibiting mineralization and, particularly, bone reabsorption. At present its use, in low dosages, is reserved to "fast bone loser" patients. CALCITONIN: It increases bone mass and significantly reduces the frequency of fractures in comparison with only calcium, but its use is limited by high costs. IPRIFLAVONE: Anti-reabsorption effects has on bone and stimulates osteoblastic activity; besides, it seems to developed the effect of estrogens on the bone. FLUORIDES: Fluorides also operate on both components of bone turnover, with a most important action on bone formation. An interesting approach is the association of low doses of monofluorophosphate with calcium. However, further confirmation of the "quality" of neoformed bone is necessary. CALCIUM: Calcium supplementation is obligatory where the alimentary supply of calcium is lower then 1 g/die or where an osteomalacic component coexists; only dosages higher than 15 g/die can produce/pharmacological effects on bone turnover. CALCITRIOL: The use is still disputed. The calcitriol-calcium association seems convincing haveved. ORG: OD 14. The efficacy of this synthetic steroid to prevent bone loss is probably superimposable on the efficacy of classic estrogen therapy.