My doc put me on Phentermine for a while and it did suppress my appetite... so if your doc will give you the go ahead and an rx, then go for it... I found the same effect with the Carb Cutter and now the Zantrex 3... I did like the Phen, but once my BMI was in line, I could not get anymore... plus I will admit, it did give me the jitters on occasion. Talk to your doc, like the post above said, it really does help but if your BMI is lower than I believe 25, you are not a good candidate and should stick with OTC. I swear by the CarbCutter and if you get it at GNC, they will take it back if it does not work for you. Good luck!