Wegovy vs Zepbound
Brand name comparison of the two FDA-approved GLP-1-based medications specifically indicated for chronic weight management.
Last updated: January 28, 2026
Dossier labels summarize each dossier's research scope. They do not establish comparative treatment benefit or safety. Read the comparison below in that context.
Semaglutide
Dossier overview
Tirzepatide
Dossier overview
Overview
Wegovy and Zepbound are brand names for two FDA-approved medications indicated specifically for chronic weight management. Wegovy contains semaglutide (2.4mg weekly), while Zepbound contains tirzepatide (up to 15mg weekly).
Both require use alongside reduced-calorie diet and increased physical activity for adults with obesity (BMI ≥30) or overweight (BMI ≥27) with weight-related comorbidities.
Key Facts
| Aspect | Wegovy | Zepbound |
|---|---|---|
| Generic Name | Semaglutide | Tirzepatide |
| Manufacturer | Novo Nordisk | Eli Lilly |
| FDA Approval | 2021 (obesity) | 2023 (obesity) |
| Mechanism | GLP-1 agonist | Dual GLP-1/GIP agonist |
Clinical Trial Evidence
STEP Program (Wegovy)
The STEP (Semaglutide Treatment Effect in People with Obesity) trials enrolled over 4,500 participants:
| Trial | Population | Weight Loss |
|---|---|---|
| STEP 1 | Adults without diabetes | -14.9% (vs -2.4% placebo) |
| STEP 2 | Adults with T2D | -9.6% (vs -3.4% placebo) |
| STEP 3 | With intensive behavioral | -16.0% (vs -5.7% placebo) |
| STEP 4 | Withdrawal study | Maintained vs regain |
SURMOUNT Program (Zepbound)
The SURMOUNT trials enrolled over 5,000 participants:
| Trial | Population | Weight Loss |
|---|---|---|
| SURMOUNT-1 | Adults without diabetes | -20.9% at 15mg (vs -3.1% placebo) |
| SURMOUNT-2 | Adults with T2D | -14.7% at 15mg (vs -3.2% placebo) |
| SURMOUNT-3 | With behavioral lead-in | -24.3% combined |
| SURMOUNT-4 | Maintenance study | Maintained vs regain |
Efficacy Comparison
| Metric | Wegovy | Zepbound |
|---|---|---|
| Placebo-Adjusted Weight Loss | ~12-15% | ~15-18% |
| ≥5% Weight Loss Achieved | 86-88% | 89-91% |
| ≥10% Weight Loss Achieved | 69-75% | 78-83% |
| ≥15% Weight Loss Achieved | 50-56% | 62-70% |
| ≥20% Weight Loss Achieved | 32-36% | 48-57% |
Ranges reflect different trial populations and doses
Mechanism Differences
| Aspect | Wegovy | Zepbound |
|---|---|---|
| Receptor Targets | GLP-1 only | GLP-1 + GIP |
| Appetite Reduction | Central GLP-1 effects | Dual receptor central effects |
| Gastric Emptying | Slowed | Slowed |
| Metabolic Effects | Insulin sensitization | Enhanced insulin sensitization |
Safety Comparison
Common Side Effects (≥5%)
| Side Effect | Wegovy | Zepbound |
|---|---|---|
| Nausea | 44% | 24-31% |
| Diarrhea | 30% | 18-23% |
| Vomiting | 24% | 9-13% |
| Constipation | 24% | 17-23% |
| Abdominal pain | 20% | 10-14% |
| Headache | 14% | 8-10% |
| Fatigue | 11% | 5-7% |
Note: Trial designs and reporting differ; direct comparison has limitations
Serious Warnings
Both medications share similar warnings:
- Thyroid C-cell tumors: Boxed warning based on rodent studies
- Pancreatitis: Discontinue if suspected
- Gallbladder disease: Increased risk of cholelithiasis
- Hypoglycemia: Risk with diabetes medications
- Acute kidney injury: Secondary to dehydration
- Suicidal ideation: Post-marketing reports (FDA monitoring)
Patient Considerations
| Factor | Wegovy | Zepbound |
|---|---|---|
| Time on Market | Longer (2021) | Newer (2023) |
| Real-World Data | More extensive | Accumulating |
| Supply Issues | Intermittent shortages | Intermittent shortages |
| Cardiovascular Data | SELECT trial: CV benefit | CV trial ongoing |
SELECT Trial Results (Wegovy)
The SELECT cardiovascular outcomes trial showed:
- 20% reduction in major adverse cardiovascular events (MACE)
- Benefit in overweight/obese adults with cardiovascular disease but without diabetes
- Led to expanded indication for cardiovascular risk reduction
Summary
Both Wegovy and Zepbound are FDA-approved for chronic weight management:
- Wegovy: First-in-class obesity GLP-1, extensive data, proven cardiovascular benefit
- Zepbound: Dual mechanism with potentially greater weight loss in trials, dosing flexibility
Key decision factors include:
- Individual efficacy and tolerability response
- Cardiovascular risk profile (SELECT trial data favors Wegovy currently)
- Insurance coverage and access
- Dose flexibility preferences
This comparison is for educational purposes only. Medication decisions should be made with a healthcare provider.
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Disclaimer: This comparison is for educational purposes only and does not constitute medical advice. Individual responses to medications vary. Always consult a qualified healthcare provider before making treatment decisions.