**4.2 Types**

There are three types of POIs currently available:


In 1992, the U.S. Food and Drug Administration (FDA) approved the marketing of DMPA as a contraceptive agent [81]. Of the three options outlined above, DMPA-IM is the most commonly used and extensively researched injectable progestin [79]. It should be administered deep into the muscles, as the preparation is released slowly into the blood stream from the site of injection [82]. For DMPA-SC, the BD Uniject™ system (Becton, Dickinson & Co., Franklin Lakes, NJ) is a useful option for community-based programs or home delivery as it can be self-administered using the system's prefilled, single-dose, disposable hypodermic syringes [83]. The efficacy of DMPA-SC is likely maintained when administered in the upper arm, abdomen, or thigh, which may be preferrable for some women [84].
