I have used it, and as far as I'm concerned it worked. But they have a fair bit of information on their site. In order for it to work most accurately it has to be taken ASAP after "whoopsies" happened. After a certain time period it's possible to not work as well as it could have. Again there's a pretty small time span, I can't remember the exact amount of hours but it says on their website. Also the few times I have had to use it the pharmacist always gave me a complete rundown on it, they even gave me a few handouts with all the info just in case. But this is not a method that should used often. To my understanding ones body can get a tolerance with it and therefore work less effectively. Again it has worked for me but I have also heard stories of the condom (breaking), birth control (used incorrectly) and Plan B have all failed. But with a few of those people went to the doctor to talk about the other things that can be done about the situation.
It is as effective as all of the other birth control/contraception things. It is highly effective, but does have the chance of failing like everything else. Its worth giving it a try though.
There's a 72 hour time span for this. Go to the site and learn more about it before making any kind of decision about it. Plan B One-Step
I used it a while ago before I was on birth control and it worked for me. A lot of people say that it fucks with your period and it can make you really sick but it didn't for me. Either way... I'm not pregnant now.