Oral contraceptives generally contain an estrogen (most commonly ethinyl estradiol) and a progestin. In their early formulations, oral contraceptives contained over 100 mg of estrogen. In these and higher doses, estrogens themselves can suppress sebum production. Estrogens also act on the liver to increase the synthesis of sex hormone-binding globulin that binds testosterone and lowers the circulating levels of free testosterone. In addition, oral contraceptives inhibit the ovarian production of androgens by suppressing ovulation. This, in turn, decreases serum androgen levels and reduces sebum production. The concentrations of estrogen in oral contraceptives have decreased over the years from 150 to 35 mg, and in the most recent forms, to 20 mg, in order to reduce the side effects associated with estrogen. (more…)