"46 yr old female. i started phentermine 37.5 on march 20 at 178 pounds. as of today march 25 i am already down to 168.  i have no problems with jitters but i crash every afternoon around 3:00. i&#039;ve tried taking a half pill first thing in the morning and the other half at lunch time but either way i crash. my goal is 150 and i really believe i&#039;ll get there with this pill!"