What Is the Strongest Strength of Phentermine?

Phentermine is a medication commonly used as a short-term weight loss aid. It is available by prescription only and comes in both tablet and capsule form, as well as in various strengths.
 
Since most of the brand-name phentermine products have been discontinued by their manufacturers, most products available (except Adipex-P®) are generic. At this time, phentermine is available in the following forms and strengths:
 
These last two items are the strongest strength of phentermine available.

The recommended dose of phentermine capsules for weight loss is 15 mg, 30 mg, or 37.5 mg once daily in the morning. For the tablets, the recommended dosage is 18.75 mg (half a tablet) or 37.5 mg (one tablet) once daily in the morning. If necessary, your healthcare provider may recommend taking half a tablet twice a day to control your appetite, although this increases the risk of insomnia.
 
(Click Phentermine and Phentermine Dosage for more information about the available forms and strengths of phentermine, tips and precautions for those using it, and what side effects may occur with the drug.)
 
Written by/reviewed by: Kristi Monson, PharmD; Arthur Schoenstadt, MD
Last reviewed by: Kristi Monson, PharmD;