Emergency contraception consists of prescribed high doses of oral contraceptive pills taken within 72 hours of unprotected intercourse. It is used in cases of method failure, when no
contraceptive was used, or in cases of rape.
It causes disruption in hormone production which renders the uterine lining unsuitable for implantation and may interfere with fertilization and cause disordered tubal transport. The treatment is most effective if used within the first 12 to 24 hours, but can be used up to 72 hours. Twenty percent of the women taking the drug experience nausea and vomiting.
Failure rate of emergency contraception is 25%. This method offers no protection against sexually transmitted diseases.