Side-by-side comparison
| Semaglutide | Tirzepatide | |
|---|---|---|
| Brands | Wegovy (weight), Ozempic (diabetes), Wegovy pill | Zepbound (weight), Mounjaro (diabetes) |
| How it works | GLP-1 agonist | Dual GLP-1 and GIP agonist |
| How often | Weekly shot, or daily pill | Weekly shot |
| Average weight loss | About 15 percent (STEP 1) | About 21 percent at the top dose (SURMOUNT-1) |
| Extra approved uses | Heart attack and stroke risk reduction, MASH liver disease | Obstructive sleep apnea with obesity |
| Common side effects | Nausea, diarrhea, constipation, vomiting | Nausea, diarrhea, constipation, vomiting |
What the head-to-head trial showed
In the SURMOUNT-5 trial, published in 2025, adults with obesity took either tirzepatide or semaglutide at their highest tolerated doses for 72 weeks. People on tirzepatide lost about 20 percent of their weight on average, compared with about 14 percent on semaglutide.
Which one is right for you?
- Tirzepatide may be a good fit if your main goal is the most weight loss, or if you have sleep apnea.
- Semaglutide may be a good fit if you have heart disease, want a pill option or your insurance covers it better.
- If one medicine causes side effects or stops working well, switching to the other is often possible.
The best medicine is the one you can take safely and keep taking. Dr. Siddiqui looks at your labs, other conditions, side effects and insurance to recommend a plan.