Independent comparison. Not affiliated with Eli Lilly or Novo Nordisk. Not medical advice.
Mounjaro vs Ozempic
Updated 30 March 2026
Two GLP-1 medications. One targets a single receptor, the other targets two. The result: Mounjaro delivers 22.5% average weight loss versus Ozempic's 15%. Here is the full comparison with real clinical data, costs, side effects, and a calculator to see what each could mean for you.
22.5%
avg body weight loss
Tirzepatide (dual GIP/GLP-1)
~$1,050/month without insurance
15.0%
avg body weight loss
Semaglutide (GLP-1 only)
~$935/month without insurance
Quick Verdict
Mounjaro wins on weight loss (22.5% vs 15%). Ozempic wins on proven heart benefits (SELECT trial). Cost is similar with insurance (~$25/month copay). Your doctor will recommend one based on whether you have diabetes, your cardiovascular risk, and insurance formulary coverage.
Full Comparison
Every clinically relevant difference, side by side.
| Feature | Mounjaro | Ozempic |
|---|---|---|
| Generic name | Tirzepatide | Semaglutide |
| Manufacturer | Eli Lilly | Novo Nordisk |
| FDA approval | 2022 (diabetes), 2023 (weight loss as Zepbound) | 2017 (diabetes), 2021 (weight loss as Wegovy) |
| Mechanism | Dual GIP + GLP-1 receptor agonist | GLP-1 receptor agonist only |
| Average weight loss | 22.5% of body weight (SURMOUNT-1) | 14.9% of body weight (STEP-1) |
| Administration | Weekly subcutaneous injection | Weekly subcutaneous injection |
| Dose range | 2.5 mg to 15 mg weekly | 0.25 mg to 2 mg weekly |
| Titration period | 20 weeks to max dose | 16 weeks to max dose |
| Monthly cost (no insurance) | ~$1,050 | ~$935 |
| Monthly cost (with insurance) | $25 with savings card | $25 with savings card |
| A1C reduction (diabetes) | Up to 2.4% reduction | Up to 1.8% reduction |
| Cardiovascular benefit | SURPASS-CVOT pending full results | Proven (SELECT trial, 20% CV risk reduction) |
| Nausea rate | 18 to 33% (dose dependent) | 20 to 30% |
| Injection device | Pre-filled single-dose pen | Multi-dose pen with needles |
| Supply availability | Intermittent shortages (improving) | Intermittent shortages (improving) |
Weight Loss and Cost Calculator
Enter your current weight to see projected weight loss and total cost on each medication.
Mounjaro (tirzepatide)
50
lbs lost (22.5%)
171
lbs target weight
$25
/month
$300
total (12 months)
Cost per pound lost: $6.06
Ozempic (semaglutide)
33
lbs lost (15%)
187
lbs target weight
$25
/month
$375
total (15 months)
Cost per pound lost: $11.36
At 220 lbs, Mounjaro projects 50 lbs of weight loss vs Ozempic's 33 lbs. That is 17 additional pounds lost with Mounjaro. With insurance, both cost roughly the same (~$25/month copay).
Weight loss projections based on average results from SURMOUNT-1 (Mounjaro) and STEP-1 (Ozempic) clinical trials. Individual results vary significantly. Insurance copay assumes commercial coverage with prior authorization.
Clinical Trial Data
Published results from the SURMOUNT (Mounjaro) and STEP (Ozempic/Wegovy) trial programs.
| Trial | Drug / Dose | Patients | Duration | Weight Loss | Placebo |
|---|---|---|---|---|---|
| SURMOUNT-1 | Mounjaro 15 mg | 2,539 | 72 weeks | 22.5% | 2.4% |
| SURMOUNT-2 | Mounjaro 15 mg (with T2D) | 938 | 72 weeks | 14.7% | 3.2% |
| STEP-1 | Wegovy 2.4 mg | 1,961 | 68 weeks | 14.9% | 2.4% |
| STEP-2 | Wegovy 2.4 mg (with T2D) | 1,210 | 68 weeks | 9.6% | 3.4% |
| STEP-8 | Wegovy vs Saxenda head-to-head | 338 | 68 weeks | 15.8% vs 6.4% | N/A |
SURMOUNT trials studied tirzepatide (Mounjaro/Zepbound). STEP trials studied semaglutide 2.4 mg (marketed as Wegovy for weight loss). Ozempic uses the same molecule (semaglutide) at a lower maximum dose (2 mg). Weight loss on Ozempic 2 mg is slightly less than Wegovy 2.4 mg.
How They Work
Mounjaro (Tirzepatide)
Mounjaro is a dual GIP and GLP-1 receptor agonist. It activates two different incretin receptors simultaneously. GLP-1 slows gastric emptying and reduces appetite. GIP enhances insulin secretion and may independently promote fat loss.
The dual mechanism is likely why Mounjaro produces more weight loss than GLP-1-only drugs. The SURMOUNT-1 trial showed that nearly 40% of patients on the 15 mg dose lost more than 25% of their body weight, a result that approaches what was previously only achievable with bariatric surgery.
Mounjaro is injected once weekly using a pre-filled, single-dose pen that does not require users to handle needles. The pen automatically inserts and retracts the needle.
Ozempic (Semaglutide)
Ozempic is a GLP-1 receptor agonist. It mimics the natural GLP-1 hormone that your body produces after eating. This slows gastric emptying (food stays in your stomach longer, making you feel full), reduces appetite at the brain level, and improves blood sugar control.
The SELECT trial (2023) demonstrated a 20% reduction in major adverse cardiovascular events (heart attack, stroke, cardiovascular death) in patients with obesity taking semaglutide. This cardiovascular benefit is currently unique to semaglutide and is a significant advantage for patients with heart disease risk.
Ozempic uses a multi-dose pen. Each pen contains 4 weekly doses, and the user attaches a new needle tip for each injection. This requires slightly more handling than Mounjaro's single-dose pen.
Who Should Choose Which?
Consider Mounjaro if:
- Your primary goal is maximum weight loss
- You have type 2 diabetes and need better A1C control
- You prefer a simpler injection device (no needle handling)
- You have not responded adequately to GLP-1-only medications
- Your insurance covers Mounjaro or you qualify for the savings card
- You do not have a history of medullary thyroid cancer or MEN2 syndrome
Consider Ozempic if:
- You have cardiovascular risk factors (proven 20% CV risk reduction)
- Your insurance covers Ozempic but not Mounjaro
- You have type 2 diabetes and want proven heart protection
- You prefer a medication with a longer real-world safety track record
- 15% weight loss would meet your health goals
- You are already on semaglutide and tolerating it well