Medroxyprogesterone is used to treat abnormal menstruation (periods) or irregular vaginal bleeding. Medroxyprogesterone is also used to bring on a normal menstrual cycle in women who menstruated normally in the past but have not menstruated for at least 6 months and who are not pregnant or undergoing menopause (change of life). Medroxyprogesterone is also used to prevent overgrowth of the lining of the uterus (womb) and may decrease the risk of cancer of the uterus in patients who are taking estrogen. Medroxyprogesterone is in a class of medications called progestins.