Are you talking about Phentermine? I was on it for a month until we could figure out why I was so hungry all the time. I don't mean cravings; I mean actual hunger, to the point of stomach growling, every HOUR, even after a full meal.
It helped me lose about 15 pounds, but I had to keep my calories at 1800 or lower, and I exercised as usual. Once my doctor figured out I have insulin resistance, thanks to a blood test, he put me on metformin and stopped the phentermine. Once the metformin starts working, my appetite will go down again (appetite was caused by too much insulin in my blood stream).
Anyway, the only side effects I had were dry mouth and insomnia. I took melatonin for the insomnia, and drinking lots and lots of water helped with the dry mouth. It had sort of a bad taste, though, like cotton mouth/morning mouth, so I sucked on a lot of breath mints too.
