Quick Summary
Mounjaro (tirzepatide) and Ozempic (semaglutide) are both injectable medications prescribed for type 2 diabetes, but they work through different mechanisms. Mounjaro is a dual GIP/GLP-1 receptor agonist, targeting two incretin hormones involved in blood sugar regulation and appetite. Ozempic is a GLP-1 receptor agonist only. According to FDA prescribing information, Mounjaro is approved as an adjunct to diet and exercise for type 2 diabetes, while Ozempic is approved for type 2 diabetes and to reduce the risk of major adverse cardiovascular events in adults with established cardiovascular disease.
In clinical trials, both medications demonstrated significant weight loss, though they were studied in different trial populations. In the SURMOUNT-1 trial, participants taking the highest dose of tirzepatide (15 mg) achieved a mean weight loss of approximately 22.5% over 72 weeks. In the STEP 5 trial, semaglutide 2.4 mg produced approximately 14.9% weight loss over 104 weeks. It is important to note that these results come from separate trials with different designs, patient populations, and durations, so direct comparison should be made with caution.
The SURMOUNT-5 trial, with results reported in May 2025, was a head-to-head study directly comparing tirzepatide and semaglutide. According to Eli Lilly, tirzepatide demonstrated statistically superior weight loss compared to semaglutide in that trial. Head-to-head data is generally considered more reliable than cross-trial comparisons for evaluating relative efficacy.
Neither Mounjaro nor Ozempic is currently FDA-approved specifically for weight management on its own label. Patients considering either medication should talk to their doctor about which option is appropriate for their individual health needs, including their diabetes management goals, cardiovascular risk profile, insurance coverage, and potential side effects.
Mounjaro vs Ozempic: Full Comparison
| Feature | Mounjaro(tirzepatide) | Ozempic(semaglutide) |
|---|---|---|
| Active Ingredient | tirzepatide | semaglutide |
| Drug Class | Dual GIP and GLP-1 receptor agonist | GLP-1 receptor agonist |
| Manufacturer | Eli Lilly | Novo Nordisk |
| FDA Approved | 2022-05-13 | 2017-12-05 |
| Approved Indications |
|
|
| Route | subcutaneous injection | subcutaneous injection |
| Frequency | Once weekly | Once weekly |
| Starting Dose | 2.5 mg weekly | 0.25 mg weekly |
| Maintenance Dose | 5 mg, 10 mg, or 15 mg weekly | 0.5 mg or 1 mg weekly |
| Max Dose | 15 mg weekly | 2 mg weekly |
| Weight Loss (%) | 22.5% | 14.9% |
| A1C Reduction | 2.4% | 1.8% |
| Key Trial | SURMOUNT-1 (72 weeks) | SUSTAIN 6 / STEP 5 (off-label weight) (104 weeks) |
| List Price | $1,023-$1,176/month | $935-$1,029/month |
| With Insurance | $25-$150/month (varies by plan) | $25-$150/month (varies by plan) |
| Savings Card | $25/month (Lilly savings card, commercially insured) | $25/month (Novo Nordisk savings card, commercially insured) |
Side Effects: Mounjaro vs Ozempic
| Side Effect | Mounjaro | Ozempic |
|---|---|---|
| Nausea | 12-18% | 15-20% |
| Diarrhea | 12-17% | 8-12% |
| Decreased appetite | 5-11% | Not reported |
| Vomiting | 5-9% | 5-9% |
| Constipation | 6-7% | 3-6% |
| Dyspepsia | 5-8% | Not reported |
| Abdominal pain | 5-6% | 6-11% |
| Injection site reaction | 3-5% | 0.2% |
| Pancreatitis (rare) | <0.5% | <0.5% |
Severity scale: 1 (mild) to 5 (serious). Based on FDA prescribing information and clinical trial data.
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This content is for informational purposes only and is not medical advice. Always consult your healthcare provider before making medication decisions. See our full medical disclaimer.