Key takeaways
Qsymia (phentermine/topiramate) and Mounjaro (tirzepatide) are both medications used to help with weight management, but they have some important differences. Qsymia is a combination of phentermine, a sympathomimetic, and topiramate, an antiepileptic, and is FDA-approved for weight loss in people over 12 living with obesity or are living with overweight and have at least weight-related condition. Mounjaro is a GIP and GLP-1 agonist approved for improving blood sugar control in adults with Type 2 diabetes but is also sometimes used off-label for weight loss. Qsymia is taken orally once a day, while Mounjaro is injected under the skin once a week. Qsymia is a controlled substance due to the phentermine component, whereas Mounjaro is not. Common side effects of Qsymia include dry mouth and constipation, while Mounjaro often causes nausea and diarrhea. Qsymia can cause a fast heart beat, while Mounjaro can increase the risk of some types of thyroid cancers. Both medications can cause problems with vision.
