Postinor-2 also known as P2 contains the active ingredient levonorgestrel. It is commonly known as the morning after pill used only as an emergency contraceptive. It is used to prevent pregnancy when taken within 72 hours (3 days) of unprotected intercourse/sex. It is not used as a regular long-term method of contraception. It reduce the chance of pregnancy in two ways: If taken before ovulation it may delay the release of the egg or if taken after ovulation it may interfere with the transport of eggs and sperm. Postinor-2 has an 85% chance of preventing pregnancy. If taken within 24 hours there is a 95% chance of preventing pregnancy. If taken after 48-72 hours there is a 58% chance. It is not known whether it is effective if taken more than 72 hours after unprotected intercourse. Products similar to Postinor-2 but from a different manufacturer include ECee2.