Merits of DMPA relative to other reversible contraceptive methods.

Of all the highly effective methods of reversible contraception, depo-medroxyprogesterone acetate (DMPA) offers the longest contraceptive activity after a single dose of any method that does not need an invasive procedure to be reversed. This is an important clinical characteristic in the context of a general correlation between duration of action and efficacy. While coitally dependent methods of birth control are the least effective, daily oral contraceptives are potentially less reliable than longer acting hormonal delivery systems, such as weekly patches, monthly injections or monthly rings. Intrauterine devices and progestin-only implants provide the lowest overall risk of failure but require provider assistance to be reversed. DMPA, administered by injection every 13 weeks, offers a comparable level of contraceptive activity but can be reversed simply by discontinuing injections.