Tirzepatide vs Semaglutide: Weight Loss, Side Effects, Price
Tirzepatide and semaglutide are both GLP-1 medicines, weekly injection versus weekly injection or daily tablet. They were tested against each other in SURMOUNT-5. Self-pay starts at $299 per month for Tirzepatide and $149 per month for Semaglutide.
- Tested head to head
- SURMOUNT-5
A quick look at Zepbound and Wegovy
Semaglutide and tirzepatide, side by side
| Tirzepatide | Semaglutide | |
|---|---|---|
| Active ingredient | tirzepatide | semaglutide |
| Manufacturer | Eli Lilly | Novo Nordisk |
| How it is taken | Weekly injection | Weekly injection or daily tablet |
| Approved for | Heart risk, weight loss, sleep apnea, and type 2 diabetes | Weight loss and heart risk, along with type 2 diabetes, kidney disease tied to type 2 diabetes, and MASH liver disease |
| First FDA approval | 2022 | 2017 |
| Average weight loss in trials | 20.9% (SURMOUNT-1, 72 weeks) | 14.9% (STEP 1, 68 weeks) |
| Most common side effect | Nausea 18% vs 4% on placebo | Nausea 20.3% vs 6.1% on placebo |
| List price | $1,112.16 per fill | $1,027.51 per pen |
| Self-pay from | $299 per month | $149 per month |
| Medicare GLP-1 Bridge | $50 per month, eligible Part D | $50 per month, eligible Part D |
| FDA shortage | Resolved December 19, 2024 | Resolved February 21, 2025 |
Sources: FDA label, FDA label (DailyMed), pricinginfo.lilly.com, Novo Nordisk pricing.
Weight loss was compared in head-to-head testing
One SURMOUNT-5 group received Tirzepatide and another received Semaglutide, so the numbers are directly comparable
| Trial | Who took part | Length | Group | Average weight loss | A1C change |
|---|---|---|---|---|---|
| SURMOUNT-5 | Adults with obesity, without type 2 diabetes | 72 weeks | Tirzepatide 10 or 15 mg weekly (Zepbound) | 20.2% | Not listed |
| SURMOUNT-5 | Adults with obesity, without type 2 diabetes | 72 weeks | Semaglutide 1.7 or 2.4 mg weekly (Wegovy) | 13.7% | Not listed |
| SURPASS-2 | Adults with type 2 diabetes on metformin | 40 weeks | Tirzepatide 5 mg weekly | Not listed | -2.01 percentage points (mean HbA1c change) |
| SURPASS-2 | Adults with type 2 diabetes on metformin | 40 weeks | Tirzepatide 10 mg weekly | Not listed | -2.24 percentage points (mean HbA1c change) |
| SURPASS-2 | Adults with type 2 diabetes on metformin | 40 weeks | Tirzepatide 15 mg weekly | Not listed | -2.3 percentage points (mean HbA1c change) |
| SURPASS-2 | Adults with type 2 diabetes on metformin | 40 weeks | Semaglutide 1 mg weekly | Not listed | -1.86 percentage points (mean HbA1c change) |
Research sources: SURPASS-2 (PubMed) and SURMOUNT-5 (PubMed)
Side effects compared
In its own label, each drug was tested against a separate placebo group, so compare each one with that placebo first.
| Side effect | Mounjaro | Placebo (Mounjaro trials) | Ozempic | Placebo (Ozempic trials) |
|---|---|---|---|---|
| Nausea | 18% | 4% | 20.3% | 6.1% |
| Diarrhea | 17% | 9% | 8.8% | 1.9% |
| Decreased Appetite | 11% | 1% | Not listed | Not listed |
| Vomiting | 9% | 2% | 9.2% | 2.3% |
| Dyspepsia | 8% | 3% | Not listed | Not listed |
| Constipation | 7% | 1% | 5% | 1.5% |
| Abdominal Pain | 6% | 4% | 7.3% | 4.6% |
Prices and coverage compared
| Medicine | How you pay | Price |
|---|---|---|
 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 |
 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 | Self-pay: LillyDirect vial or KwikPen 2.5 mg | $299 per month |
| Zepbound | Commercial plan that does not cover it | $299 per month |
| Zepbound | Medicare GLP-1 Bridge (Zepbound KwikPen, eligible Part D) | $50 per month |
 Ozempic | List price before insurance | $1,027.51 per pen |
| Ozempic | Ozempic Savings Offer (insured) | for up to 3 months, starting at $25 each month |
| Ozempic | Self-pay: Ozempic pill (from 1.5 mg) | $149 per month |
 Wegovy | List price before insurance | $1,349.02 per month |
| Wegovy | Wegovy Savings Offer (insured) | from $25 per month |
| Wegovy | Self-pay: Wegovy pill 1.5 mg | $149 per month |
| Wegovy | Medicare GLP-1 Bridge (Wegovy, eligible Part D) | $50 per month |
 Rybelsus | List price before insurance | $1,027.51 per 30 tablets |
| Rybelsus | RYBELSUS Savings Offer (insured) | for 1-, 2- or 3-month supplies, fill pricing begins at $25 |
Prices checked November 2026 (12)
sources include pricinginfo.lilly.com 1 2, mounjaro.lilly.com, zepbound.lilly.com, Eli Lilly, CMS, Novo Nordisk pricing 1 2, NovoCare 1 2, TrumpRx, and rybelsus.com.
Who should pick which?
- Tirzepatide is approved as a treatment for sleep apnea.
- Semaglutide has that approval for type 2 diabetes with kidney disease.
- MASH liver disease is an approved use of Semaglutide.
- Cash payments for Semaglutide begin at $149 per month, which is the lower starting price.
Your prescriber weighs your health history, coverage, and other medicines. Whether you switch between them is their decision.