Phentermine has worked for me but, that was only part of the equation. I started taking them in February 2012 and have lost 80lbs. I felt very bad when I first starting taking them - sweating, no concentration and feeling high. I used to cut them in half and start taking them at 11am. Also I would skip days. My doctor said I was not using it correctly but I continued to lose weight and I have not built up a big tolerance. My doctor had gastric bypass at the same time I started taking Phentermine and he is amazed at what I have done. I've stopped taking blood pressure meds. I have stopped taking diabetes meds. I have stopped taking cholesterol meds. I read a book called: "The Power Of Habit" and learned how to modify bad habits. I now exercise with my Bowflex and elliptical four to five times per week and I feel great. The major side effect to Phentermine is irritability. My family says I'm a bear to get along with. I didn't think about this side effect until my doctor asked me if this was happening to me. I have been mean to my whole family but, I see my biceps growing and my stomach getting rock hard and shrinking. I will never go back to being fat once I lose another 50lbs. I have changed completely and I could never go back just like I said I couldn't lose weight last year. I have had 20 years with this weight and now I'm in control. Phentermine will not work nor will gastric bypass. They are just crutches to aid in the healing. The true exercise to master is your mind. I don't believe in good luck. So "Good Health".View Thread