"i started this medication a little over a month ago. i seemed to have a lot more energy at first and as of today i&#039;ve lost 10 lbs. a few days ago however, i began experiencing chest tightness and shortness of breath. i went to my pcp who then sent me to the er. i completed multiple tests and stayed overnight in the hospital for evaluation. everything came back without any definitive answers as to the symptoms i&#039;ve been experiencing. several doctors mentioned that they believe the phentermine to be the cause and recommended that i stop using it. it is now day 4 without taking any and i&#039;m still feeling the same symptoms. only time will tell... if i feel better after a week then i suppose they were correct."