Are hormonal contraceptives less effective in overweight and obese women?

Loss of efficacy of hormonal contraceptives is of particular concern for women who are overweight or obese. Only recently have clinical trials started to include overweight and obese women in their study populations, limiting the data available on which to make the best prescribing decisions for hormonal contraceptives for these patients. Other methods, such as the copper or levonorgestrel-containing intrauterine device, the etonogestrel implant, and depot medroxyprogesterone acetate, are preferred over combined oral contraceptives, the transdermal patch, and the vaginal ring.