Oral contraceptives (OCs) have been shown to effectively treat acne. Clinical trials of various doses of ethinyl estradiol (EE) combined with progestins such as levonorgestrel, desogestrel, norgestimate, gestodene, cyproterone acetate and drospirenone in monophasic, triphasic and combiphasic formulations used to treat acne in women are reviewed here. Open-label and comparative studies beginning in the 1980s were the first to demonstrate objective and subjective reductions in the incidence of acne, severity of existing acne and seborrhea. Placebo-controlled trials have corroborated these findings with a trend toward effective acne treatment with declining doses of EE. Significant reductions in total, inflammatory and noninflammatory lesions compared with placebo have been demonstrated with an OC containing the low dose of 20 microg of EE. Collectively, these findings support the use of low-dose OCs for the treatment of acne.