Zepbound vs Mounjaro: Weight Loss, Side Effects, Price
Zepbound and Mounjaro contain the same medicine, tirzepatide, from Eli Lilly, but carry different approvals: Zepbound for weight loss and sleep apnea, Mounjaro for type 2 diabetes and heart risk.
A quick look at Zepbound and Mounjaro
Side-by-side: Zepbound and Mounjaro
| Zepbound | Mounjaro | |
|---|---|---|
| Medicine | Zepbound |  Mounjaro |
| Active ingredient | tirzepatide | tirzepatide |
| Manufacturer | Eli Lilly | Eli Lilly |
| How it is taken | Weekly injection | Weekly injection |
| Approved for | Weight loss and sleep apnea | Type 2 diabetes and heart risk |
| First FDA approval | 2023 | 2022 |
| Average weight loss in trials | 20.9% (SURMOUNT-1, 72 weeks) | Not listed |
| Most common side effect | Nausea 29% vs 8% on placebo | Nausea 18% vs 4% on placebo |
| List price | $499 to $1,086 per fill | $1,112.16 per fill |
| Self-pay from | $299 per month | Not listed |
| Medicare GLP-1 Bridge | $50 per month, eligible Part D | Not listed |
| FDA shortage | Resolved December 19, 2024 | Resolved December 19, 2024 |
Sources: FDA label, FDA label (DailyMed), pricinginfo.lilly.com, TrumpRx.
Comparing weight loss
No direct study has compared the two drugs, so these results come from separate trials with different groups and timeframes.
| Trial | Who took part | Length | Group | Average weight loss | Placebo | A1C change |
|---|---|---|---|---|---|---|
| SURMOUNT-1 | Adults with obesity or overweight, without diabetes | 72 weeks | Tirzepatide 5 mg weekly | 15% | 3.1% | Not listed |
| SURMOUNT-1 | Adults with obesity or overweight, without diabetes | 72 weeks | Tirzepatide 10 mg weekly | 19.5% | 3.1% | Not listed |
| SURMOUNT-1 | Adults with obesity or overweight, without diabetes | 72 weeks | Tirzepatide 15 mg weekly | 20.9% | 3.1% | Not listed |
| SURMOUNT-2 | Adults with obesity or overweight who also have type 2 diabetes | 72 weeks | Tirzepatide 10 mg weekly | 12.8% | 3.2% | Not listed |
| SURMOUNT-2 | Adults with obesity or overweight who also have type 2 diabetes | 72 weeks | Tirzepatide 15 mg weekly | 14.7% | 3.2% | Not listed |
| SURPASS-1 | Adults with type 2 diabetes who rely on diet and exercise alone | 40 weeks | Tirzepatide 5 mg weekly | Not listed | Not listed | -1.87 percentage points (mean HbA1c change) |
| SURPASS-1 | Adults with type 2 diabetes who rely on diet and exercise alone | 40 weeks | Tirzepatide 10 mg weekly | Not listed | Not listed | -1.89 percentage points (mean HbA1c change) |
| SURPASS-1 | Adults with type 2 diabetes who rely on diet and exercise alone | 40 weeks | Tirzepatide 15 mg weekly | Not listed | Not listed | -2.07 percentage points (mean HbA1c change) |
Sources for the trials are SURMOUNT-1 (FDA label (DailyMed)), SURMOUNT-2 (PubMed), and SURPASS-1 (PubMed).
Side effects compared
Each drug was tested in its own group of people with a separate placebo group, so compare each drug with its own placebo first.
| Side effect | Zepbound | Placebo (Zepbound trials) | Mounjaro | Placebo (Mounjaro trials) |
|---|---|---|---|---|
| Nausea | 29% | 8% | 18% | 4% |
| Diarrhea | 23% | 8% | 17% | 9% |
| Constipation | 17% | 5% | 7% | 1% |
| Vomiting | 13% | 2% | 9% | 2% |
| Abdominal Pain | 10% | 5% | 6% | 4% |
| Dyspepsia | 10% | 4% | 8% | 3% |
| Injection Site Reactions | 8% | 2% | Not listed | Not listed |
| Fatigue | 7% | 3% | Not listed | Not listed |
| Decreased Appetite | Not listed | Not listed | 11% | 1% |
Price and coverage compared side by side
| Medicine | How you pay | Price |
|---|---|---|
| Zepbound | List price before insurance | $499 to $1,086 per fill |
| Zepbound | Zepbound Savings Program (insured) | from $25 for up to a 3-month fill |
| Zepbound | Commercial plan that does not cover it | $299 per month |
| Zepbound | Self-pay: LillyDirect vial or KwikPen 2.5 mg | $299 per month |
| Zepbound | Self-pay: LillyDirect vial or KwikPen 5 mg | $399 per month |
| Zepbound | LillyDirect self-pay: 7.5 mg through 15 mg (your refill must happen no later than 45 days) | $449 per month |
| Zepbound | Self-pay: the regular price applies when you do not refill within 45 days | you pay $499 for $7.5 mg or $699 for $10 to $15 mg each month |
| Zepbound | Self-pay via TrumpRx | $299 per month |
| Zepbound | Medicare GLP-1 Bridge (Zepbound KwikPen, eligible Part D) | $50 per month |
| Mounjaro | List price before insurance | $1,112.16 per fill |
| Mounjaro | Mounjaro Savings Card (insured) | from $25 for up to a 3-month fill |
| Mounjaro | Commercial plan that does not cover it | $499 per month |
Prices checked November 2026 (7)
pricinginfo.lilly.com 1 2, zepbound.lilly.com, Eli Lilly, TrumpRx, CMS, mounjaro.lilly.com.
Who should pick which?
- If you want to lose weight and do not have diabetes, Zepbound is the only one approved.
- For type 2 diabetes, only Mounjaro has that approval.
- For sleep apnea, Zepbound is approved as a treatment.
- Mounjaro is approved to lower the risk of heart attack and stroke.
- Mounjaro is approved for some children under 18.
- Under Medicare, Zepbound is on the Medicare GLP-1 Bridge list.
- Paying cash yourself costs $299 per month at the published Zepbound self-pay price.
Your prescriber considers your health history, other medicines and coverage. Whether you switch between the two drugs is their decision.