"i started taking phentermine 03/29 at 241.6lbs. i was 265lbs in 2010 and lost weight naturally and went to the gym and got down to 211lbs and got lazy and the weight has crept back up. i didn&#039;t think the rx would work but today 03/30 i was 237.6 after just 1 day. i worked out for 2hrs on my 1st day and had to leave because i was so nauseous. i got a headache and nausea on day 1 and could barely eat. today was day 2 and my head has been hurting and i&#039;ve been nauseous for over 10hrs and couldn&#039;t go to workout. i am taking 37.5mg i&#039;m the mornings. i read the headache may be hunger or dehydration so i forced down an apple and naked chicken breast but it was hard to get down and symptoms didn&#039;t go away. i&#039;m gonna try to stick with it."