How efficient is plan b if taken no more than 5 hours after unprotected sex? worried.

Very effective: Plan B is very effective in preventing pregnancy if taken within 48-72 hrs after intercourse

Very up to 120hrs: When taken as directed, emergency contraception is effective up to 120hrs (5 days) after unprotected sex. Check out http://www.plannedparenthood.org/health-info/morning-after-pill-emergency-contraception.

PlanB: is 95% effective if taken within the first 24 hours after unprotected intercourse. It has no effect on STDs.