Effect of low-dose oral contraceptives on androgenic markers and acne

Oral contraceptives (OC) suppress excess androgen production; however, different progestins in combination with low-dose estrogens produce divergent effects on sex hormone-binding globulin (SHBG) and testosterone that may influence clinical outcomes. This multicenter, open-label, randomized study compared biochemical androgen profiles and clinical outcomes associated with two OC containing the same amounts of ethinyl estradiol (EE, 20 μg) but different progestins, levonorgestrel (LNG, 100 μg), and norethindrone acetate (NETA, 1000 μg). Fifty-eight healthy women (18-28 years old) received three cycles of treatment with LNG/EE (n = 30) or NETA/EE (n = 28). The results showed that LNG reduced androgen levels in three compartments - adrenal, ovarian, and peripheral. NETA reduced only adrenal and peripheral androgens. Despite a 2.2-fold greater relative increase in SHBG with NETA than LNG, bioavailable testosterone (T) was reduced by the same amount with LNG and NETA. Both treatments improved acne and were well tolerated. Low-dose OC (EE, 20 μg) are effective in reducing circulating androgens and acne lesions without causing weight gain. Although LNG and NETA affected secondary markers differently, both OC formulations produced an equivalent decrease in bioavailable T. (C) 1999 Elsevier Science Inc.