The Depo Provera shot is the only birth control method proven to cause weight gain. Most women do not gain weight on the pill, patch, or ring. When they do it is usually no more than five pounds and may be due to other causes. Some women also lose weight when using these methods. Ultimately, you may require some trial and error in finding the right birth control method for you, but we wouldn’t expect your new birth control to cause weight gain for you.