"Zepbound vs Ozempic" is one of the most searched comparisons in this class, and the question inside it is usually which one works better? The labels answer a different question first: these are not two versions of one drug. They are different molecules from different companies, approved for different conditions, and no trial has compared the two brands directly.
This page sets out what the two current labels say, side by side, and points to the trials that do compare the molecules. The pharmacology of the molecules themselves is on tirzepatide vs semaglutide.
Side by side, from the labels
| Zepbound | Ozempic (injection) | |
|---|---|---|
| Molecule | Tirzepatide | Semaglutide |
| Acts on | GIP and GLP-1 receptors | GLP-1 receptor |
| Maker | Eli Lilly | Novo Nordisk |
| Approved for | Weight reduction and long-term maintenance in adults with obesity, or overweight with a weight-related condition; moderate to severe obstructive sleep apnoea in adults with obesity | Glycaemic control in adults with type 2 diabetes; reducing major cardiovascular events in type 2 diabetes with established heart disease; reducing kidney decline, kidney failure and cardiovascular death in type 2 diabetes with chronic kidney disease |
| Weight-management indication | Yes | No |
| Forms | Single-dose pen, single-dose vial, multi-dose KwikPen | Multi-dose pen |
| Same molecule, other brand | Mounjaro (type 2 diabetes) | Wegovy (obesity); Rybelsus and Ozempic tablets (type 2 diabetes) |
| Current label | DailyMed 487cd7e7…, effective 2026-08-28 | DailyMed adec4fd2…, effective 2026-06-01 |
The last row but one is the key to the search. The four brands form two pairs of the same molecule under different labels: Zepbound and Mounjaro are both tirzepatide; Wegovy and Ozempic are both semaglutide. So "Zepbound vs Ozempic" crosses both lines at once — molecule and indication.
Why the weight figures on the two labels cannot be compared
Each label reports body weight, but from trials that were designed to answer different questions.
| Zepbound, Study 1 (SURMOUNT-1) | Ozempic, 30-week monotherapy trial | |
|---|---|---|
| Who | 2,539 adults with obesity or overweight, without diabetes | 388 adults with type 2 diabetes |
| Length | 72 weeks | 30 weeks |
| Primary aim | Weight | Blood sugar (HbA1c) |
| Weight change on drug | −15.0%, −19.5%, −20.9% (three arms) | −3.8 kg and −4.7 kg (two arms) ≈ −4.2% and −4.9% |
| Weight change on placebo | −3.1% | −1.2 kg ≈ −1.3% |
Ozempic percentages computed by glp1ledger from the label's reported kilograms and baseline weights (89.8, 96.9 and 89.1 kg).
Setting −20.9% against −4.9% would be the wrong comparison: the Ozempic trial ran less than half as long, in people with diabetes — who lose less weight on these drugs, as Zepbound's own second study shows (−12.8% and −14.7% in type 2 diabetes against −3.2% on placebo) — and at doses below the obesity dose of semaglutide sold as Wegovy.
The trials that do compare the molecules
No trial has randomised people between the brands Zepbound and Ozempic. Two trials compare the molecules under matched conditions:
- SURPASS-2 compared tirzepatide with semaglutide 1 mg in type 2 diabetes — in brand terms, Mounjaro against Ozempic. It is covered on Mounjaro vs Ozempic.
- SURMOUNT-5 compared Zepbound with Wegovy in adults with obesity and without diabetes — the obesity doses of both molecules. It is covered on Zepbound vs Wegovy.
Someone asking "which works better for weight loss?" is asking the SURMOUNT-5 question; someone asking about blood-sugar control is asking the SURPASS-2 question.
Coverage: where the indication decides the bill
Because Ozempic's label covers type 2 diabetes and Zepbound's covers obesity and sleep apnoea, insurers treat them differently:
- Ozempic is generally covered as a diabetes medicine for people with type 2 diabetes. Using it for weight loss without diabetes is off-label — legal for a prescriber, but outside the label, and plans commonly require a diabetes diagnosis before they pay.
- Zepbound is a weight-management drug, and many employer plans exclude that category entirely. Where it is covered, prior authorization usually applies — see what plans ask before approving it. Medicare Part D excludes weight-loss drugs by statute, with the Bridge programme as the current exception; see GLP-1 insurance coverage.
Self-pay routes for both, dated: Zepbound cost, Ozempic cost, and Lilly's cards on Zepbound savings card.
Safety in common, and one label line that matters here
Both labels carry the class's boxed warning about thyroid C-cell tumours and share warning sections on acute pancreatitis, acute gallbladder disease, low blood sugar, kidney injury from fluid loss, severe gastrointestinal reactions, diabetic retinopathy complications and pulmonary aspiration during anaesthesia or deep sedation. Side-effect rates by brand are on Zepbound side effects and Ozempic side effects.
Zepbound's label adds a limitation that bears directly on this comparison: coadministration "with other tirzepatide-containing products or with any glucagon-like peptide-1 (GLP-1) receptor agonist is not recommended." Ozempic is one. The two are alternatives, not a combination.
What this page does not answer
- Which is right for a particular person. That depends on whether they have type 2 diabetes, sleep apnoea, heart or kidney disease, their other medicines and their coverage — a decision for the prescriber.
- Dosing. This publication does not cover doses; how either drug is started and increased is set out in its label.
Sources
- Zepbound (tirzepatide) injection prescribing information, Eli Lilly and Company, DailyMed set ID 487cd7e7-434c-4925-99fa-aa80b1cc776b, effective 2026-08-28 — sections 1, 3 and 14 (Studies 1 and 2, Table 2).
- Ozempic (semaglutide) injection prescribing information, Novo Nordisk, DailyMed set ID adec4fd2-6858-4c99-91d4-531f5f2a2d79, effective 2026-06-01 — sections 1 and 14 (monotherapy trial NCT02054897, Table 3 and body-weight text).
- Rybelsus and Ozempic (semaglutide) tablets prescribing information, Novo Nordisk, DailyMed set ID 27f15fac-7d98-4114-a2ec-92494a91da98 — section 1.
- All read from DailyMed on 30 September 2026.