Because they both act as sympathomimetics, Phentermine and Phentramin-d have some of the same side effects. However, with both diet pills you will also experience appetite suppression and a boost in energy and mood.

With the over-the-counter weight loss supplement phentramin-d, the active ingredients are both known and the mechanism of action is known. There are basically two ingredients in phentramin-d. Both have been created in an FDA-approved laboratory and neither are plant extracts or impure compounds.