Will plan b still work after 72 hours ?

Plan B: If you take it within 72 hours after you've had unprotected sex, Plan B One-Step can reduce the risk of pregnancy by up to 89%. If you take Plan B One-Step within 24 hours, it is about 95% effective. But you should know that Plan B One-Step is not as effective as regular contraception.

A/W Dr Jones Singer: Plan B One-Step is up to 89 % effective when taken within 72 hours (3 days) after unprotected sex. It can reduce chance of pregnancy by up to 95% if used within 24 hours. It continues to reduce the risk of pregnancy up to 120 hours (5 days) after unprotected sex, but is less effective as time passes. It would be best to take the Plan B One Step immediately after the episode of failed birth control