Plan B Contraceptive Pill

Also known as a "morning-after pill," Plan B One-Step™ (levonorgestrel) is an emergency contraceptive that is used to prevent pregnancy when used within 72 hours after unprotected sex. Plan B originally came in a two-step formulation, which consisted of two tablets taken 12 hours apart. It has been replaced by the new formulation, which consists of just one tablet.
Plan B is available by prescription for people under 17 years old or over-the-counter (OTC) for those 17 and older. In some states, specially trained pharmacists may dispense the medication to all women, regardless of age, without a prescription. Taking Plan B within 72 hours after unprotected sex reduces the risk of pregnancy by 89 percent.
(To learn more about this emergency contraceptive pill, including dosing guidelines and side effects, click Plan B.)
Last reviewed by: Arthur Schoenstadt, MD