Abstract To avoid the risks of oestrogen therapy in post-menopausal women, we have examined the effects of a progestin, megestrol acetate (MA), on hot flushes and bone metabolism. Ten normal post-menopausal women were studied before and after the oral administration of 20, 40 and 80 mg of MA daily for 4 wk at each dose level. Finger temperature and skin resistance were recorded for 8 h as objective indices of flushing and perspiration, respectively. The fasting ratios of urinary calcium: creatinine (Ca/Cr) and hydroxyproline: creatinine (OHPr/Cr) were used as indices of bone resorption. A reduction (P