"i am a 5&#039;4&quot; 42 year old woman who was diagnosed with hypothyroidism in 2000 and went from 130 lbs to 164 lbs overnight.  i&#039;ve been trying to lose the weight with a nutritionist and through exercise.  i even ran and trained for a 1/2 marathon in 2006 and 2007.  the lowest i could ever get was 150 lbs and if i quit running long distances, the weight comes back.  i started taking phentermine on july 2 and have lost about 10 pounds. my only side effects are extreme thirst and occasional anxiousness."