What is Plan B One Step ®? Plan B One-Step® is an emergency contraception pill containing a progestin hormone called levonorgestrel. Progestin-only pills can reduce your risk of getting pregnant by 88% if taken within a few hours of the sexual encounter. If a woman has had sex without using birth control or if something happened (such as a condom broke), she can use emergency contraception to reduce her risk of becoming pregnant. Plan B One Step ® is a form of emergency contraception that is available at military pharmacies and commercial drug stores without need for a prescription and with no age limitations