"i started taking phentermine on november 4 and today is my 3rd day.  my starting weight is 254lbs. my goal is to lose 100lbs. since starting i feel like i have so much energy and have been able to keep up with my 4 kids so much easier.  the only side effect that i have is a mild headache and a little jittery.  i haven&#039;t been hungry but force myself to eat because i know the importance of nutrition for your body. this morning i made egg-whites for breakfast and sliced tomato but had to force it down."