Oral contraceptives have several mechanisms of action in treating acne. They reduce androgen production by both the ovaries and the adrenal glands. Oral contraceptives also reduce free serum testosterone by increasing sex hormone-binding globulin. Sebum production is decreased with oral contraceptive use, possibly due to androgen reduction or possibly directly due to increased levels of estrogens (77). Most formulations consist of an estrogen in combination with a progestin. Progestin is needed to minimize the increased risk of endometrial cancer with unopposed estrogens. Progestins themselves have intrinsic androgenic activity, which can worsen acne in addition to causing changes in lipid metabolism and glucose intolerance (85). The newer generations of progestins (second and third generations) have been formulated to have lower androgenic properties. The second – generation progestins include ethynodiol diacetate, norethindrone, and levonorgesterol. The third-generation progestins have less cross reactivity with the androgen receptor, and increase sex hormone binding globulin. These oral contraceptives that lessen androgenic activity include: desogestrel, norgestimate, and gestodene. Only two oral contraceptives are currently FDA-approved for the treatment of acne, Ortho Tri-Cyclen® (Ortho, Raritan, NJ) and Estrostep® (Parke Davis Laboratories, Detroit, MI). Ortho Tri-Cyclen® is a triphasic contraceptive contaning ethinyl estradiol (35 micrograms) and the third-generation progestin, norgestimate. Estrostep® contains ethinyl estradiol (graduated dose from 20-35 micrograms), and the second-generation progestin, norethindrone acetate (86).
Clinical improvement due to hormonal therapy will be evident as early as three months. Hormonal therapy is especially beneficial for acne in a “beard” distribution, involving the mandible and chin. Co-management with a patient’s gynecologist is needed so that patients may be appropriately followed while on an oral contraceptive. Often times, the oral contraceptives approved for acne may not be the best choice for patients experiencing heavy or abnormal menses. Relatively common side effects from oral contraceptives includes: nausea, vomiting, abnormal menses, weight gain, and breast tenderness. More detrimental but rarer side effects include: thrombophlebitis, pulmonary embolism, and hypertension (87). The risk of these serious side effects increases in patients who smoke cigarettes.