"2 days taking phentermine 37.5 and i feel great. i am 5&#039;10 and 40 years old- starting weight 224.8 and two days later i at 218.0lbs. i&#039;m under doctors care while taking these and she has me taking them for 2 months maybe 3. the only side effects for me is dry mouth and the first day taking them a little blurry vision only lasting 1 min. my appetite has completely vanished and its easy making the right food choices.  my goal weight is around 170.  i have a very positive outlook now that i can do this and will start exercising 3 days a week."