How long after consuming assure is it effective for?

Assure, a brand of emergency contraceptive pill, is effective when taken within 72 hours (3 days) after unprotected intercourse. Its effectiveness diminishes the longer you wait, and it is most effective when taken as soon as possible. If taken within 24 hours, it can prevent pregnancy about 95% of the time. However, it is not intended for regular contraceptive use and won't be effective if implantation has already occurred.