Some progestins have androgenic activity and can produce androgenic side effects such as increased sebum production (oilier skin), acne, and hirsutism (excessive facial/body hair growth), as well as changes in liver protein production. Only certain progestins are androgenic however, these being the testosterone derivatives and, to a lesser extent, the 17α-hydroxyprogesterone derivatives medroxyprogesterone acetate and megestrol acetate. No other progestins have such activity (though some, conversely, possess antiandrogenic activity). Moreover, the androgenic activity of progestins within the testosterone derivatives also varies, and while some may have high or moderate androgenic activity, others have only low or no such activity.