Head-to-head comparison
Wegovy vs Zepbound: What the Trial and the Price Lists Actually Show
One trial compared them directly. It has a clear winner and two caveats. Then there is the price, which points the other way, and a refill condition that can more than double it.
- 20.2% / 13.7%Weight loss at 72 weeks, tirzepatide against semaglutide, head to head
- $1,200Extra a year for Zepbound at maintenance, paying cash
- 20.7%What semaglutide reached at its newer higher dose, in a separate trial
- 45 daysThe Zepbound refill window; miss it and the top dose goes to $1,049
The short version
At the doses that were compared, Zepbound produced more weight loss than Wegovy, and the difference was large. Zepbound also costs more, and it attaches a condition to its cheapest price that Wegovy does not. Their side effects are close to identical.
Wegovy is semaglutide; Zepbound is tirzepatide. Semaglutide acts on one receptor, GLP-1. Tirzepatide acts on two, GLP-1 and GIP. That is the mechanical difference, and it is the usual explanation offered for the gap in results — though a mechanism that sounds like it should work better is not evidence that it does. The trial is the evidence.
Wegovy vs Zepbound weight loss, head to head
SURMOUNT-5 randomised 751 adults with obesity but without type 2 diabetes to the maximum tolerated dose of one drug or the other, injected weekly for 72 weeks. Maximum tolerated rather than fixed matters: it is closer to how these are actually prescribed.
What the trial found
Tirzepatide −20.2% (95% CI −21.4 to −19.1). Semaglutide −13.7% (CI −14.9 to −12.6). The intervals do not overlap, which is what makes the difference convincing rather than suggestive.
Waist circumference fell 18.4 cm against 13.0 cm. Participants on tirzepatide were also more likely to reach every threshold the trial measured — 10%, 15%, 20% and 25% of body weight.
Two features of the trial belong in any honest reading of it. It was open-label — participants and investigators knew which drug was being given, and for an outcome as behaviourally sensitive as body weight, knowing you were assigned the drug reputed to work better is not nothing. And it was funded by Eli Lilly, which makes tirzepatide. Neither invalidates the result. Both belong in the body text rather than a footnote.
The comparison is already out of date in one respect
SURMOUNT-5 used semaglutide at 2.4 mg, because that was the approved maximum. A higher dose has since been tested. In the STEP UP trial, semaglutide at 7.2 mg produced an average of 20.7% weight loss at 72 weeks, against 17.5% on 2.4 mg and 2.4% on placebo. A third of participants on the high dose lost 25% or more, roughly double the proportion on the standard dose.
Worth knowing
20.7% is numerically above tirzepatide’s 20.2%. That comparison is not valid — different trials, different participants, different baselines. It is the error that produces confident wrong answers, and it is everywhere.
The defensible statement is narrower: the gap between these two drugs looks smaller at semaglutide’s higher dose than the head-to-head trial suggested, and only a new head-to-head at 7.2 mg would establish by how much. None has reported. Anyone quoting you a precise figure for that comparison is inventing it.
Zepbound vs Wegovy cost, paying cash
Both manufacturers now sell direct. These are their own published self-pay prices, read on 26 August 2026.
| Per month | Twelve months | |
|---|---|---|
| Wegovy tablet, 9 or 25 mg | $299 | $3,588 |
| Wegovy pen, 2.4 mg | $349 | $4,188 |
| Wegovy pen HD, 7.2 mg | $399 | $4,788 |
| Zepbound, 7.5–15 mg — refilled on time | $449 | $5,388 |
| Zepbound, 15 mg — refilled late | $1,049 | $12,588 |
The arithmetic
At maintenance, Zepbound costs $5,388 a year against $4,188 for the standard Wegovy pen. That is $1,200 more for roughly six and a half percentage points of additional weight loss.
The condition matters as much as the price. Lilly’s $449 rate requires each refill to be completed within 45 days of the previous delivery. Outside that window, 12.5 mg is $849 and 15 mg is $1,049. A 45-day window against a roughly 30-day supply leaves about two weeks of slack — workable, but a delayed shipment, a lapsed prescription or a pause for side effects can cost the difference. Wegovy attaches no equivalent condition. Full breakdowns for both are in our pricing analysis.
Zepbound vs Wegovy side effects
Close to identical in kind. Both labels lead with nausea, diarrhoea, vomiting, constipation and abdominal pain. Zepbound’s list adds injection site reactions and hair loss; Wegovy’s adds headache and fatigue. Both carry the same boxed warning about thyroid C-cell tumours seen in rats, and both are contraindicated in anyone with a personal or family history of medullary thyroid carcinoma or MEN 2. Our side effects page has the frequencies with their placebo rates.
The head-to-head trial reported gastrointestinal effects as most common in both arms, mostly mild to moderate, and concentrated during dose escalation. It did not find one drug meaningfully better tolerated than the other. If someone tells you one is easier on the stomach, that is not coming from this trial.
Which is better?
On weight loss at the doses compared, Zepbound, clearly. That is the one question the evidence answers directly, and it answers it in one direction.
Everything else complicates it. Wegovy is cheaper at every comparable point, and cheaper still as a tablet. Semaglutide’s higher dose narrows a gap nobody has yet measured properly. Zepbound’s price carries a scheduling condition that can more than double it. Side effects do not separate them. And neither trial nor price list can tell you how you personally will respond, which is the variable that actually decides the outcome and the one nobody can quote.
Frequently asked questions
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Wegovy vs Zepbound: which is better for weight loss?
In the only trial that compared them directly, Zepbound: 20.2% average weight loss at 72 weeks against 13.7%. The trial was open-label and funded by Zepbound’s manufacturer, and it used Wegovy at a dose that is no longer the maximum available.
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Is Zepbound cheaper than Wegovy?
No. At maintenance Zepbound is $449 a month against $349 for the standard Wegovy pen and $299 for the tablet. Zepbound is only cheaper at its 2.5 mg starting dose, which is not a dose anyone stays on.
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How does the Wegovy pill compare with Zepbound?
On price, favourably: $299 a month at the higher tablet doses against $449. On effectiveness there is no head-to-head trial between the Wegovy tablet and Zepbound, so any comparison of the two is inference rather than evidence.
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Where does Ozempic fit in?
Ozempic is the same drug as Wegovy — semaglutide — approved for type 2 diabetes rather than weight management, at lower maximum doses. Comparing Ozempic with Zepbound for weight loss is really comparing a diabetes dose of semaglutide with a weight-loss dose of tirzepatide, which is not a like-for-like question.
Sources and method
- The head-to-head trial. Aronne LJ, Horn DB, le Roux CW, et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity. New England Journal of Medicine, 3 July 2025;393(1):26–36. SURMOUNT-5, NCT05822830. Open-label; funded by Eli Lilly.
- The higher semaglutide dose. Once-weekly semaglutide 7·2 mg in adults with obesity (STEP UP): a randomised, controlled, phase 3b trial. The Lancet Diabetes & Endocrinology, 2025.
- Pricing. Read from NovoCare Pharmacy and LillyDirect on 26 August 2026. The 45-day refill condition and the out-of-window prices are stated in Lilly’s Self Pay Journey Program terms.
- Side effects. The FDA-approved prescribing information for each product.
- Method and limits. Twelve-month totals are the monthly price times twelve at a single dose; a real first year costs less because titration starts lower. We have not compared the two drugs at semaglutide’s 7.2 mg dose because no trial has done so, and we do not compare results across separate trials. Prices change frequently and carry dated offers.
Full pricing breakdown → Side effects in detail → Where to get a prescription →
Prices verified 26 August 2026. We recheck pricing quarterly and after any announced change.