Zepbound vs Wegovy: the side-by-side on obesity's two dominant drugs
Both are FDA-approved for chronic weight management. They're made by different companies, built on different receptor mechanisms, and produce different average weight loss. Here's the head-to-head, cited.
Zepbound (tirzepatide) and Wegovy (semaglutide) are the only two drugs FDA-approved specifically for chronic weight management as of April 2026. Both are once-weekly injections. Zepbound is a dual GIP/GLP-1 receptor agonist; Wegovy is a single GLP-1 agonist. In head-to-head trial data, Zepbound produced larger average weight loss; both have comparable side-effect profiles dominated by GI events.
| Field | Zepbound | Wegovy |
|---|---|---|
| Brand names | tirzepatide | semaglutide |
| Manufacturer | Eli Lilly | Novo Nordisk |
| FDA approved | 2023 (chronic weight management) | 2021 (chronic weight management) |
| Indication | Chronic weight management in adults with BMI ≥30, or ≥27 with weight-related comorbidity | Chronic weight management in adults with BMI ≥30, or ≥27 with weight-related comorbidity; approved for adolescents age 12+ |
| Mechanism | Dual GIP / GLP-1 receptor agonist | GLP-1 receptor agonist (single pathway) |
| Delivery | Once-weekly subcutaneous injection | Once-weekly subcutaneous injection |
| Avg weight loss | ~20.2% at 72 weeks (SURMOUNT-5, head-to-head) | ~13.7% at 72 weeks (SURMOUNT-5, head-to-head) |
Primary sources
- Zepbound: SURMOUNT-5 (NEJM, 2025)
- Wegovy: SURMOUNT-5 (NEJM, 2025)
Frequently asked
Which one causes more weight loss on average?
Zepbound. In the SURMOUNT-5 head-to-head trial, Zepbound produced 20.2% mean weight loss vs Wegovy's 13.7% at 72 weeks. Individual responses vary considerably.
Are the side effects different?
Broadly similar. Both are dominated by GI side effects — nausea, diarrhea, constipation, vomiting — and both are dose-dependent. Discontinuation rates for side effects in trials are comparable (~4-7%).
Which one is cheaper?
List prices are close: ~$1,060/month for Wegovy, ~$1,060-1,300/month for Zepbound depending on dose. With insurance for obesity, coverage is inconsistent for both. Manufacturer savings programs (NovoCare, LillyDirect) can reduce cost for eligible patients.
Can I switch between them?
Yes, with a prescribing clinician's guidance. Switching typically restarts titration at a low dose to minimize GI side effects. Don't switch without medical supervision.
Is Zepbound available as a tablet?
No. Zepbound is injection-only. Wegovy is also injection-only; its oral counterpart Rybelsus is approved for Type 2 diabetes, not obesity.