The FDA has approved a progestin-only oral contraceptive ("minipill") containing drospirenone (Slynd – Exeltis). All other progestin-only oral contraceptives available in the US contain norethindrone (Camila, and others). Progestin-only oral contraceptives are similar in efficacy to combination oral contraceptives. They are used predominantly by breastfeeding women and by those in whom estrogen is poorly tolerated or contraindicated. Combination oral contraceptives containing drospirenone and ethinyl estradiol have been available for years.