Ozempic vs Mounjaro
Ozempic and Mounjaro are both once-weekly injectable GLP-1 medications for type 2 diabetes, but they work through different mechanisms and produce different magnitudes of weight loss.
| Field | Ozempic | Mounjaro |
|---|---|---|
| Active ingredient | Semaglutide | Tirzepatide |
| Receptors activated | GLP-1 | GIP + GLP-1 (dual) |
| Manufacturer | Novo Nordisk | Eli Lilly |
| Maximum maintenance dose | 2.0 mg weekly | 15 mg weekly |
| Average A1C reduction (max dose) | ~1.8 percentage points | ~2.4 percentage points |
| Average weight loss in trials | ~6-10% | ~15-22% |
Single vs dual agonist
Ozempic activates one incretin receptor — GLP-1. Mounjaro activates two: GLP-1 and GIP. The dual mechanism appears to produce stronger metabolic and appetite effects, which is why head-to-head trials show greater weight loss and greater A1C reductions with Mounjaro at maximum doses.
Side effects
The side-effect profiles are similar in type (gastrointestinal) but different in pattern: Mounjaro patients in trials reported slightly more injection-site reactions, and Ozempic patients reported slightly more nausea at comparable doses. Both are typically worst in the first weeks of each new dose.
Choosing between them
For A1C control and weight management together, Mounjaro is often more potent. Ozempic has a longer real-world track record and the 2024 SELECT trial established benefits for cardiovascular outcomes in people with heart disease and obesity. Decisions depend on your goals, insurance, and tolerance.