Plan B is a form of emergency contraception. It is usually sold under the name “Plan B One Step.” Effective in preventing pregnancy when taken up to 72 hours after unprotected sexual intercourse, Plan B works in one of two ways, depending on when in the menstrual cycle it is ingested. It can either prevent ovulation or interfere with fertilization. It is also possible that Plan B affects the uterine lining works to prevent implantation.
More About Plan B
Taken within 24 hours of intercourse, Plan B is 95% effective in preventing pregnancy. When taken within 72 hours, it is 89% effective.
It is important to note that Plan B is completely different from RU-486 which causes abortion. Plan B is intended to prevent pregnancy, not end it.
Plan B is available over the counter without prescription or proof of age.