"i&#039;m a 39 yr old man 6&quot; 250 lbs.  started phentermine 37.5 november 30th, my doctor put me on one pill in the morning and a half in the afternoon. i have lost 5.4 pounds in a week. side effects with me are dry mouth, hard to sleep the first few nights, slight tingling in my arms. it does suppress my appetite and that&#039;s what i need."