Injectable contraception.

Injectable contraception has many advantages and is a popular birth control method worldwide. Its efficacy is independent of a daily action or an intervention around the time of coitus. It is highly efficacious and well tolerated in general. In the United States, the available injectable contraceptive is depot medroxyprogesterone acetate (DMPA). Its use is associated with a decrease in bone mineral density (BMD) that is largely if not completely reversible over time and very comparable to the BMD loss associated with pregnancy and breastfeeding. The available knowledge on the impact of BMD loss on the risks of fractures later in life is incomplete, but in the light of the small magnitude of impact of DMPA on BMD and its reversibility, any increase in the risk of osteoporotic fractures is likely to be small. This article reviews the recent evidence on DMPA's efficacy, risks and benefits, and side effects with a focus on bone health issues.