Key takeaways
Phentermine (Adipex-P) and semaglutide (Ozempic) are both medications used to help with weight management, but they belong to different drug classes and have important differences. Phentermine is a sympathomimetic stimulant primarily used for short-term weight loss in adults with a high body mass index (BMI), while semaglutide is a glucagon-like peptide-1 (GLP-1) agonist used to treat Type 2 diabetes and reduce the risk of heart problems in adults with diabetes. Ozempic is sometimes used off-label for weight loss. Phentermine is taken orally, usually once a day, and is available in various forms, including tablets and capsules. In contrast, semaglutide is an injection used under the skin once a week. Phentermine is a controlled substance due to its potential for misuse and dependence, whereas semaglutide is not. Common side effects of phentermine include dry mouth and trouble sleeping, while semaglutide often causes nausea and diarrhea. Additionally, phentermine is available as a lower-cost generic, whereas semaglutide is only available as a brand-name medication.
