Here's a link on another thread about duromine, if that is the sort of thing you are talking about.

My advice is DON'T DO IT!!!! I haven't done it myself, but a friend was on them and she was crazy on them. They seriously messed with her head and metabolism. She did lose weight, but when she went off them, she gained it all back and then some.
I thought there was one around but I couldn't find it... must have looked straight past it. I will also go and read this.
Thanks. x