"i started taking phentermine 37.5mg, 1/2 tablet in the morning,  along with a water pill and chromium picolinate a month ago. i was advised to start out taking only half a tablet for as long as possible since the body can build up a resistance to it. when and if i need to i can take the full 37.5 mg daily.  i went to the dr today for my one month checkup and to refill my meds. i lost 17 lbs!!!  the worst side effects are dry mouth and constipation. i&#039;ll suffer through the side effects for the energy burst i get from the phentermine and weight loss."