"today is my first day taking phendimetrazine 35 mg. i was taking phentermine 37.5 mg before, phentermine helped me lose 15 pounds in less than a month but then it stopped helping suppress my appetite so the doctor told me to take phendimetrazine along with the phentermine. so i am supposed to take 1 pill of phentermine in the morning before noon and then take phendimetrazine in the afternoon around 4 or 5 p.m. i haven&#039;t had any food cravings as of yet. i do feel very energetic. i had a headache earlier in the day but that was because i hadn&#039;t eaten anything. "