In people using progestin-only contraceptives, most studies do not show an increase in weight or body fat, but some do show a small increase (11). Some people will gain weight on birth control, and some people may be more prone to weight gain than others.

Which birth control pill causes weight gain?

One study showed that, over one year, women who used Depo-Provera gained five pounds more than those using a copper IUD. The reason Depo-Provera can cause weight gain, Dr. Stanwood explains, is that it can activate signals in the brain that control hunger.

Does the pill actually cause weight gain?

Most studies oppose the theory that hormonal birth control causes weight gain. Still, some do report gaining a few pounds in the weeks and months after they start taking the pill. This is often temporary and the result of water retention, not actual weight gain.