I've been taking Phentermine for over a month now. It has been a great tool. That's it though, a tool.
I am eating smarter. I am going to the gym to work out once or twice a week and swimming with my boys once a week. (I hope to add more days to my workout schedual, but I am doing the best I can, and not quitting.)
The only side effect I have had is occasional dry mouth. That's it. As a matter of fact, I can actually focus on task BETTER now, then when I wasn't on it.
As for weight loss. I really haven't kept track. I've lost 21 pounds total, but that is since the middle of January. I've only had the pills half that time.