Key takeaways
Benzphetamine (Didrex) and phentermine (Adipex-P) are both sympathomimetic medications used for short-term weight management in adults. They work by suppressing appetite. Both medications are taken orally and are controlled substances due to their potential for misuse and dependence. However, there are several differences between them. Benzphetamine is a Schedule III medication, while phentermine is a Schedule IV medication, meaning phentermine may have a lower risk of misuse and dependence. Benzphetamine is available only as an oral tablet, whereas phentermine comes in various forms, including tablets, capsules, and orally disintegrating tablets. Phentermine is approved for use in individuals with a BMI of 27 kg/m² or greater with weight-related conditions, while benzphetamine is approved for those with a BMI of 30 kg/m² or greater. Both medications can cause a fast heart beat, restlessness, and high blood pressure and interact with monoamine oxidase inhibitors (MAOIs). Neither one should not be combined with other weight loss medications.
