Phentermine Pill Types

What is the difference between blue and yellow phentermine ?

Here is the laymans answer as we understand it. For a more technical explanation, please contact the manufacturers Eon Labs and Purepac

The yellow 30mg capsules and the blue/clear 30 mg capsules act the same. They both have the same active ingredient (i.e. Phentermine Hydrochloride). There is no generic equivalent for Ionamin, which is the timed release resin form of Phentermine.

Both of these capsules are manufactured by Eon Labs. The blue/white version is a generic for Fastin and the yellow is just a generic phentermine. The ingredients are the same. The only real difference is the price per pill.

As for the 15 mg capsules, they are simply a lower dosage form of Phentermine that is manufactured by Eon Labs.
The 37.5 mg Phentermine is a generic for Adipex-P that is manufactured by Purepac. The only real difference between the brand name (Adipex-P, manufactured by Gate Pharm) and the generic is the price.