According to the search results, long-term use of Depo-Provera may cause a decrease in bone mineral density, which increases the risk of osteoporosis. This risk is higher if the shot is taken for more than 2 years. In a study of teenage girls who used Depo-Provera for more than 2 years, their hip bones did not completely recover by 5 years after they stopped using it. However, taking calcium and Vitamin D and exercising daily may lessen the loss of calcium from your bones. If you need a birth control method for more than 2 years, your healthcare provider may switch you to another birth control method instead of using Depo-Provera. If you continue using Depo-Provera, your healthcare provider may ask you to have a bone test, especially if you have other risks for weak bones.