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How long is Plan B effective?

Plan B 1-Step has been FDA approved for use within 72 hours after unprotected sex. However, recent studies have found that emergency contraception can prevent pregnancy up to 120 hours (5 days) after unprotected sex.

The best possible success from Plan B happens when women start the treatment as soon as possible after unprotected sex.

Please note: Results show a higher rate of effectiveness when taken as soon as possible after unprotected sex. Effectiveness declines the longer the woman waits to take it.