The authors have compared the results obtained using four main drugs (calcitonin, ipriflavone, transdermal estrogens, fluorine-calcium) actually employed for the treatment of post-menopausal osteoporosis, administered to four groups of fast loser patients (442) in natural (months mean 19.97 +/- 5.99) and surgical (months mean 16.94 +/- 4.29) menopause. After six months of treatment, the efficacy of therapy has been evaluated on the basis of BD (bone density) and osteoarticular pain changes. The BD results have been compared with those of 100 non-treated patients, in the same clinical conditions. The authors have noticed an increase in bone mass (from +0.47% to +1.59%) and a great improvement in osteoarticular pain with all therapeutical protocols used while in the control group there was a progressive decrease of BMC (-1.23%) and a worsening pain. Comparing the results obtained with different therapies, the difference of mean mineralometric gain is not particularly significant among several treatments; but this difference is very significant between treated and non-treated patients who have continued to lose bone mass. The collateral effects, observed during administration of different drugs, have been minimal and the suspension of therapy has been always associated to their disappearance. In the opinion of the authors the good results, achieved with different therapies, depend on the precocity of the treatment, but also on the fact that, in peri-menopausal period, their effect has been increased by the estrogens. Being osteoporosis a multifactorial pathology, a careful control of the risk factors is appropriate and needs to be enforced in order to carry out a precocious treatment with specific drugs on bone metabolism and try to balance the natural turnover with the loss of bone mass.