Mounjaro vs Ozempic
Different medicines. Mounjaro is tirzepatide, a dual GIP + GLP-1 agonist; Ozempic is semaglutide, a GLP-1 agonist. Both are once-weekly injections FDA-approved for type 2 diabetes.
At a glance
| Attribute | Mounjaro | Ozempic |
|---|---|---|
| Active drug | tirzepatide | semaglutide |
| Drug class | Dual GIP + GLP-1 receptor agonist | GLP-1 receptor agonist |
| FDA-approved for | Type 2 diabetes | Type 2 diabetes |
| How it's taken | Once-weekly injection | Once-weekly injection or once-daily tablet |
| Maker | Eli Lilly | Novo Nordisk |
The short version
Unlike Wegovy vs Ozempic (the same drug), Mounjaro and Ozempic are genuinely different medicines. Mounjaro (tirzepatide, Eli Lilly) acts on two gut hormones — GIP and GLP-1 — while Ozempic (semaglutide, Novo Nordisk) acts on one, GLP-1. Both are once-weekly injections FDA-approved for type 2 diabetes.
The key difference
The mechanism is the headline: tirzepatide's dual action is why it's often linked with greater average weight loss. For weight management specifically, the sibling brands are Zepbound (tirzepatide) and Wegovy (semaglutide) — and a 2025 head-to-head trial (SURMOUNT-5) found tirzepatide produced greater average weight loss than semaglutide. For diabetes, the choice is individualized: A1c goals, side effects, cost, and coverage all matter.
What the trials showed on weight
In weight-management trials, tirzepatide averaged about 20% body-weight reduction (SURMOUNT-1, 15 mg) versus about 15% for semaglutide (STEP 1), and outperformed it in a direct head-to-head (SURMOUNT-5). Diabetes-specific results differ and should be discussed with your clinician. These are trial averages, not promises — individual results and tolerability vary.
Bottom line
Mounjaro and Ozempic aren't interchangeable — they're different drugs. Tirzepatide (Mounjaro/Zepbound) tends to produce more weight loss on average, but the right choice depends on your diagnosis, response, side effects, and cost. This is general information, not medical advice.
Frequently asked
- Is Mounjaro the same as Ozempic?
- No. Mounjaro is tirzepatide (a dual GIP + GLP-1 agonist from Eli Lilly); Ozempic is semaglutide (a GLP-1 agonist from Novo Nordisk). They're different molecules, both once-weekly injections approved for type 2 diabetes.
- Which is better for weight loss, Mounjaro or Ozempic?
- In weight-management trials the tirzepatide brand (Zepbound) averaged more weight loss than the semaglutide brand (Wegovy), including a 2025 head-to-head (SURMOUNT-5). Neither Mounjaro nor Ozempic is FDA-approved for weight loss itself; the weight brands are Zepbound and Wegovy. The right option is individualized — talk to your clinician.
- Do Mounjaro and Ozempic have different side effects?
- Both share the GLP-1 class effects — nausea, diarrhea, constipation — and both carry a boxed warning about thyroid C-cell tumors seen in rodents. Tirzepatide's dual mechanism can differ in tolerability for some people. Review the full FDA label and your history with a clinician.
Compare more GLP-1 options
Sources
- DailyMed — FDA drug labels (search a brand to read its prescribing information) ↗
- Wilding et al., STEP 1: Once-Weekly Semaglutide in Adults with Overweight or Obesity — NEJM 2021 (PubMed) ↗
- Jastreboff et al., SURMOUNT-1: Tirzepatide Once Weekly for the Treatment of Obesity — NEJM 2022 (PubMed) ↗
- Aronne et al., SURMOUNT-5: Tirzepatide as Compared with Semaglutide for the Treatment of Obesity — NEJM 2025 (PubMed) ↗
General information, not medical advice, and not a substitute for your clinician. Efficacy figures are pivotal-trial averages — individual results, side effects, and cost vary. Only a licensed healthcare professional can choose, start, switch, or dose these medicines.