weight loss
"I dropped 35 pounds on this medication in 6 months without exercising. I also took up smoking cigarettes and heavy drinking to counteract the jitters that can leave you unable to sleep. (Not a good combination for your body.) You have to literally force yourself to eat.  Your body will build up a tolerance to it, even at increased dosages, and eventually you will have to get off of it.  So if you have not established a healthy change of lifestyle (which was my unattained goal to begin with) you will gain the weight back, which I did. I also have suspected liver damage from combining phentermine with Aleve and alcohol.  Side effects: heavy armpit sweating and mental fog."