Most methods will not cause weight gain. Many young women are starting birth control for the first time while their body is going through many other changes. Some women gain weight naturally when transitioning from their teens into their twenties. If that happens to be when a woman starts birth control, it’s easy to put the blame on the pill, patch, the implant, the hormonal IUD, or ring. The truth is each of these methods can be used without an expected weight gain.
A recent study showed about 1 in 4 women who use the shot will gain some weight. However, the majority of women (3 out of 4) don’t gain much weight. So most women using the shot are able to keep their weight steady with healthy eating and regular exercise.