Black women are the most likely to gain weight while using a long-acting form of contraception, such as a hormone implant or intrauterine device (IUD)

Researchers found that during a year of using progestin-based long-term contraceptives, black women put on an average of four to six pounds, compared to a trend of slight weight loss or smaller weight gain for white and other women. Researchers found that regardless of the contraceptive method used, black women tended to put on more weight than others.