Sirky,
Here's some info I found online about this drug:
http://www.drugs.com/adipex.html I don't think it sounds like a good idea, and I can see why your doc won't prescribe it!
Check out some of the threads around 3FC here, you'll find TONS of good advice and information!
Oh, duh, I see that Anne already posted this link. Well, anyway, I think you get the idea!