Emergency contraceptionBy Mayo Clinic staff
Emergency contraception helps prevent pregnancy after unprotected sex. Emergency contraception isn't meant to be used in place of routine birth control — but it's an option if you've had unprotected sex, your method of birth control failed or you missed a birth control pill.
To be effective, emergency contraception must be used as soon as possible after unprotected sex. In the U.S., two types of emergency contraception are available: pills and intrauterine device (IUD).
Emergency contraception pills are also known as the morning-after pill. Three brands — Next Choice, Plan B One-Step and Ella — are available. Emergency contraception pills can be used up to five days after unprotected sex. However, the pills are more effective the sooner you take them.
Another option is a copper IUD. The brand name is ParaGard. To prevent pregnancy, the IUD must be inserted within five days after unprotected sex.