What is the difference between Mounjaro and Ozempic?
Last updated September 3, 2026.
Mounjaro (tirzepatide) activates GIP and GLP-1 receptors; Ozempic (semaglutide) activates GLP-1 only, and in their head-to-head trial tirzepatide won on both A1C and weight. The SURPASS-2 trial randomized people with type 2 diabetes on metformin to tirzepatide 5, 10, or 15 mg or semaglutide 1 mg for 40 weeks. Mean A1C fell 2.01, 2.24, and 2.30 percentage points on the three tirzepatide doses versus 1.86 points on semaglutide, and tirzepatide was superior at every dose. Body weight fell more too, with treatment differences of 1.9, 3.6, and 5.5 kg. The most common adverse events in both groups were gastrointestinal. One caveat for a fair reading: the trial used semaglutide 1 mg, not the higher 2 mg dose approved later for diabetes. Both molecules have weight-loss brand versions (Zepbound and Wegovy). Neither trial result overrides individual factors like your other medications, kidney function, or what your plan covers.
What to do
- Bring the trial to your prescriber: SURPASS-2 is the direct comparison and favors tirzepatide on average.
- Ask about your A1C goal: the mean difference was roughly 0.2 to 0.4 percentage points between drugs.
- Factor in weight: if weight loss is a treatment goal, tirzepatide's edge was larger there.
- Check your formulary: coverage and prior authorization rules differ between the two.
Related questions
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