---
title: "Wegovy vs Zepbound: Which Loses More Weight?"
description: "Wegovy is semaglutide; Zepbound is tirzepatide. In SURMOUNT-5, Zepbound led — but cost and tolerability differ."
canonical: https://glpeak.ai/answers/wegovy-vs-zepbound
reviewer: Sydney Duong, RD, GLPeak Clinical Lead
last_updated: 2026-06-17
category: comparison
---

# Wegovy vs Zepbound: Which Loses More Weight?

> **Quick answer:** In the SURMOUNT-5 head-to-head trial, Zepbound 15 mg produced ~20.2% average weight loss over 72 weeks versus ~13.7% on Wegovy 2.4 mg. Zepbound's dual GIP/GLP-1 mechanism appears to drive the difference. Choice between them still depends on insurance, tolerability, and prescriber preference.

## Different molecules, different mechanisms

Wegovy is semaglutide, a single-agonist that activates only the GLP-1 receptor. Zepbound is tirzepatide, a dual-agonist that activates both GLP-1 and GIP (glucose-dependent insulinotropic polypeptide). GIP appears to amplify the satiety and metabolic effects.

## Head-to-head trial results

SURMOUNT-5 (2025) directly compared the two over 72 weeks in adults with obesity but without diabetes.

- Zepbound 15 mg: ~20.2% average weight loss
- Wegovy 2.4 mg: ~13.7% average weight loss
- More Zepbound patients reached ≥25% weight loss

## Side-effect tolerability

Both share the same GI side-effect profile (nausea, constipation, reflux, fatigue). In SURMOUNT-5, discontinuation rates were similar. Some patients tolerate one better than the other for reasons that aren't fully understood.

## Cost and access

List prices are similar (~$1,000–$1,350/month for pens). Eli Lilly's LillyDirect vial program for Zepbound offers self-pay pricing of ~$349–$499/month, generally lower than Novo Nordisk's Wegovy self-pay options. Insurance coverage varies by plan.

## Frequently asked questions

### Is Zepbound better than Wegovy?

On average and at maximum doses, Zepbound produced more weight loss than Wegovy in the SURMOUNT-5 head-to-head trial (~20.2% vs ~13.7% over 72 weeks). 'Better' for an individual still depends on cost, insurance coverage, and how well each is tolerated.

### Can I switch from Wegovy to Zepbound?

Yes, with prescriber guidance. There's no direct dose conversion because the molecules differ. A common approach is to restart at Zepbound 2.5 mg for 4 weeks, then move to 5 mg, regardless of prior Wegovy dose.

### Do they have the same side effects?

Mostly yes — nausea, constipation or diarrhea, reflux, and fatigue are the most common for both. The intensity varies by individual and dose.

### Which is cheaper, Wegovy or Zepbound?

Self-pay through LillyDirect generally makes Zepbound vials cheaper than Wegovy. Through insurance, prices depend on your plan's formulary tier and prior-authorization requirements.

## References

- [SURMOUNT-5 (NEJM)](https://www.nejm.org/doi/full/10.1056/NEJMoa2416394)
- [STEP 1 (NEJM)](https://www.nejm.org/doi/full/10.1056/NEJMoa2032183)

---
_Educational only — not medical advice._