Excuse me, but I'm currently in med school. These types of painkillers are effective, but dangerous. I wouldn't know, mostly because I was never "peer" pressured by troglodytes to partake in anything illegal, but I would approve any future course of action with a professional.
I had a friend that would get them from time to time a couple years ago. We went to the bars one night so i figured i'd try one out. It was a "Perc 12", i remember feeling great and wouldn't shut the fuck up. Since then my buddy has been to detox twice. He borrowed $50 bucks from me and i haven't heard from him since.