Depo-Provera is an injectable contraceptive for women, which is classified as a "progestin" drug. This form of contraception prevents ovulation, or the release of eggs from the ovaries, and thins the uterine lining. Over the years since Depo-Provera was approved by the U.S. Food and Drug Administration, studies have shown that long-term use of Depo-Provera can result in the loss of bone density, which may be irreversible. Plus, consumers over the age of 35 who have used Depo-Provera over the last four or five years may be at a greater risk of developing breast cancer than those women who have not used the drug. Depo-Provera also causes a laundry list of other types of side effects, some of which may be quite severe. For instance, studies have shown a link between depression and Depo-Provera usage, as well as shortness of breath, seizures, vomiting, and coughing up blood, to name a few of the more serious potential side effects of using Depo-Provera.