Levonorgestrel
"I took it one hour after I had sex, 6 days later I bled lightly and thought I was spotting which scared the heck out of me. My period was 5 days late, but it came, and since it was my first time using Aftera or any type of birth control, it threw my period off which is what it is intended to do. It worked therefore it gets a 10 from me, I am 20 and 160lbs. PS: don't be stupid and continue to have unprotected sex after you take it because it won't protect against that!"