"i started taking phentermine on 07/21/15 at starting weight of 136.  i am very petite at 4&#039;9 and  wanted to go back to my usual weight of 115. today is 08/02/15 and i am down to 127. i have been somewhat dieting and exercising once every few days. only downside to the medication is the extreme dry mouth and makes me very jittery the whole day. i take 1 pill every morning."