"overall, i think phentermine works great as a weight loss aid. and for me the side effects were minimal. however i decided to stop taking it, hoping to maintain the weight i was at. i still maintained a fairly reasonable (not perfect) diet and exercised at least 30 min 3-5 times a week. within 6 weeks i had gained 15 lbs. i was so irritated, and i didn&#039;t know what to do besides go back on the pill. i started taking the pill again. in the first month i lost 14 lbs. so i guess i just wanted to warn everyone that if you stop taking it, the weight can climb back on."