Wegovy vs Zepbound: Weight Loss Drug Showdown
Medically reviewed by Medical Advisory Board Last reviewed 2026-09-27
Both FDA-approved for obesity — but the drug, the data, and the results differ
Wegovy (semaglutide 2.4 mg) and Zepbound (tirzepatide 15 mg) are both FDA-approved weekly injections for obesity, but they are different drugs with different mechanisms and different trial results. Zepbound produces more average weight loss; Wegovy has a longer safety and cardiovascular outcomes track record. This guide helps you choose.
Wegovy vs. Zepbound is the comparison on the minds of everyone considering a weight-loss injection. Both are weekly subcutaneous injections, both are FDA-approved for chronic weight management, and both cost roughly $1,000/month without coverage. The key difference is that Wegovy is semaglutide, a GLP-1 agonist, while Zepbound is tirzepatide, a GIP + GLP-1 dual agonist, and their trial numbers diverge meaningfully.
If you also have Type 2 diabetes, the diabetes-branded versions of these drugs, Ozempic and Mounjaro, may be relevant. See our Ozempic vs Mounjaro guide. For the broader GLP-1 context, visit our GLP-1 guide. And if you're comparing one brand from each manufacturer, see our Wegovy vs Mounjaro and Zepbound vs Ozempic comparisons.
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| Factor | Wegovy (semaglutide 2.4 mg) | Zepbound (tirzepatide up to 15 mg) |
|---|---|---|
| Active ingredient | Semaglutide | Tirzepatide |
| Mechanism | GLP-1 receptor agonist | GIP + GLP-1 dual receptor agonist |
| FDA approval (obesity) | June 2021 | November 2023 |
| Average weight loss (pivotal trial) | ~14.9% (STEP-1 at 68 weeks) | ~20.9% (SURMOUNT-1 at 72 weeks) |
| % losing ≥20% body weight | ~32% (STEP-1) | ~57% (SURMOUNT-1) |
| CV outcomes trial | SELECT (2023) — 20% reduction in MACE | SURMOUNT-MMO ongoing; preliminary data positive |
| Dosing schedule | Weekly; max 2.4 mg | Weekly; max 15 mg |
| List price | ~$1,349/month | ~$1,060/month |
The Mechanism Difference That Drives the Results
Wegovy suppresses appetite and slows gastric emptying by activating GLP-1 receptors in the gut and brain. Zepbound does all that and also activates GIP receptors — GIP amplifies GLP-1's appetite effect and appears to improve fat metabolism directly. That extra pathway accounts for the larger average weight loss in tirzepatide trials.
Critically, 57% of Zepbound patients lost 20% or more of their body weight in SURMOUNT-1, versus about 32% with Wegovy in STEP-1. That top-responder rate is a meaningful clinical difference, not just an average.
When to Choose Wegovy
Wegovy may suit you if:
- You have established cardiovascular disease — Wegovy's SELECT trial showed a statistically significant 20% reduction in major cardiovascular events.
- You want the drug with the longest obesity-approval history and most published real-world data.
- You or your insurer already have a prior authorization approval in place.
- You have tried semaglutide (Ozempic) for diabetes and know you tolerate it.
When to Choose Zepbound
Zepbound may suit you if:
- Maximizing weight loss is the primary goal — the average and top-responder numbers are both higher.
- You have not achieved enough weight loss on semaglutide and want to try the dual-agonist mechanism.
- Your insurer covers Zepbound more readily (this varies significantly by plan).
If results stall on either drug, see our GLP-1 plateau guide for what metabolic factors to address.
The Verdict
Zepbound wins on average weight loss; Wegovy wins on cardiovascular outcomes evidence. If your main goal is the largest possible weight reduction and you do not have CVD as a primary concern, tirzepatide is the stronger choice by current data. If heart disease prevention matters as much as weight, Wegovy's SELECT data is the compelling argument. Both require a prescription and medical supervision. Take our free assessment or book a consultation to work through which fits your specific history.
What to Look For in a Body-Composition Scale
A bioimpedance scale trends body fat and muscle rather than just weight — useful when the number stalls but your composition is improving. The absolute body-fat % isn't lab-accurate, so use it for TRENDS at a consistent time of day. Choose one that syncs to an app so you can watch the trend line.
Frequently Asked Questions
Does Zepbound cause more weight loss than Wegovy?
On average, yes. In their respective pivotal trials, Zepbound (tirzepatide) produced average weight loss of about 20.9% versus Wegovy's (semaglutide) 14.9%. The share of patients losing 20% or more of body weight was also much higher with Zepbound (~57% vs ~32%). These were separate trials with slightly different populations, but a 2024 real-world head-to-head study corroborated greater weight loss with tirzepatide.
Is Wegovy or Zepbound covered by insurance?
Coverage for both is inconsistent and evolving. Neither is reliably covered by Medicare Part D for weight loss alone (though this is changing). Commercial insurance coverage has expanded significantly in 2024–2025, but often requires prior authorization, a BMI ≥30 (or ≥27 with comorbidities), and sometimes a documented history of diet/exercise failure. Zepbound entered the market with manufacturer coupon programs that can bring costs below $500/month for commercially insured patients.
Are the side effects of Wegovy and Zepbound different?
Very similar. Both cause nausea, vomiting, diarrhea, and constipation primarily during dose escalation. For the head-to-head SURMOUNT-5 numbers, see GLP-1 side effects compared. Both carry the same black-box warning about thyroid C-cell tumors (based on animal data), and both carry a rare pancreatitis risk. Some data suggests tirzepatide may cause slightly more early nausea, though the rates converge as titration progresses. Neither should be used during pregnancy.
Can I switch from Wegovy to Zepbound?
Yes, with medical guidance. Switching is straightforward in principle — stop semaglutide, start tirzepatide at 2.5 mg, and titrate. In practice, the timing depends on why you are switching (plateau, side effects, access) and your current dose. A clinician can set the right restart timing based on your history.
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