Ozempic and Zepbound are not two versions of one drug, and they are not approved for the same thing. Ozempic is Novo Nordisk's semaglutide, labelled for type 2 diabetes.1 Zepbound is Lilly's tirzepatide, labelled for weight reduction and obstructive sleep apnoea.34 If you want semaglutide for weight, the labelled product is Wegovy, not Ozempic.7
The two side by side
| Ozempic | Zepbound | |
|---|---|---|
| Molecule | Semaglutide, a GLP-1 receptor agonist6 | Tirzepatide, a GIP and GLP-1 receptor agonist5 |
| Maker | Novo Nordisk | Eli Lilly |
| Labelled for | Type 2 diabetes (blood sugar, heart and kidney risk)1 | Weight reduction and long-term maintenance; sleep apnoea34 |
| Weekly doses | 0.25, 0.5, 1, 2 mg1 | 2.5, 5, 7.5, 10, 12.5, 15 mg4 |
| Same molecule, other label | Wegovy (weight) | Mounjaro (diabetes) |
What each one is approved for
Ozempic's label lists three uses, all in adults with type 2 diabetes: to "improve glycemic control", to reduce major cardiovascular events in those with established heart disease, and to reduce kidney decline in those with chronic kidney disease.1 Weight loss is not on that list. Prescribing it for weight is off-label: legal, common, and a call for your prescriber.
Zepbound's label is the opposite: "to reduce excess body weight and maintain weight reduction long term in adults with obesity" (or overweight with a related condition), plus obstructive sleep apnoea.34 For type 2 diabetes, Lilly sells the same molecule as Mounjaro, and Lilly's own Mounjaro site says "Mounjaro is not a weight loss drug."13
The fair weight-loss comparison is Zepbound against Wegovy, which is semaglutide with the weight label: "to reduce excess body weight and maintain weight reduction long term".7 We cover that pair in Zepbound vs Wegovy.
The label also decides coverage. Insurers approve Ozempic against diabetes criteria. Aetna's policy, for example, grants it "for a diagnosis of type 2 diabetes mellitus" where metformin has not worked, is not tolerated or cannot be used.11 Without that diagnosis, expect a denial and a cash price.
Which loses more weight
In SURMOUNT-5, the one trial that put the two molecules head to head, tirzepatide reduced body weight by 20.2% at 72 weeks and semaglutide by 13.7%.9 That favours Zepbound's molecule clearly.
Read the doses, though. The trial took semaglutide to 1.7 or 2.4 mg and tirzepatide to 10 or 15 mg.10 Ozempic's highest dose is 2 mg.1 So the trial compared Zepbound's range with Wegovy's range, not with Ozempic as prescribed. It still points one way; it just was not a test of Ozempic.
How each dose ladder runs
Both start low and climb in four-week steps, to let the stomach adjust. Your prescriber sets your dose and how fast you move; what follows is the labels' schedules.
- Ozempic: "Start at 0.25 mg once weekly. After 4 weeks, increase the dosage to 0.5 mg." The label then allows 1 mg after at least four weeks on 0.5 mg, and 2 mg after at least four weeks on 1 mg.1 Four rungs.
- Zepbound: 2.5 mg for four weeks, then 5 mg, then 2.5 mg steps "after at least 4 weeks on the current dose", to a maximum of 15 mg. The 2.5 mg dose "is not approved as a maintenance dosage". Maintenance for weight is 5, 10 or 15 mg.4 Six rungs.
The full tirzepatide schedule, week by week, is in the tirzepatide dosage chart; the semaglutide one is in the semaglutide dosage chart.
What each costs from the maker
Both makers publish self-pay prices, and both climb with dose. Novo's Ozempic self-pay is $349 a month at 0.25, 0.5 and 1 mg and $499 a month at 2 mg, with new NovoCare patients paying $199 for each of their first two fills at 0.25 or 0.5 mg through December 31, 2026.2 Lilly's Zepbound self-pay, for the vial or KwikPen, is $299 at 2.5 mg, $399 at 5 mg, $499 at 7.5 mg and $699 at 10, 12.5 and 15 mg.8
With a commercial plan that covers the drug, both cards go lower. Novo's Ozempic offer: "Pay as little as $25, subject to a maximum savings of $100/month", government beneficiaries excluded.2 Lilly's Zepbound card: "as low as $25 for a one- or three-month supply" of single-dose pens when your plan covers it.8 Lilly lists Zepbound at $499 to $1,086.37 per fill before any of that.8
The cheaper cash routes
Both molecules are also sold compounded through telehealth programs, for less than either brand. Compounded drugs "are not FDA-approved", which means FDA "does not verify the safety, effectiveness or quality" of them before sale.12 That is the trade. Today's verified prices, all in:
Before you pick a compounded seller, read how to check a seller and what compounded tirzepatide is.
The honest summary
If you have type 2 diabetes, Ozempic is an on-label choice and coverage is realistic. If you want a weight-loss drug, Zepbound carries that label and its molecule beat semaglutide head to head, while semaglutide's weight-loss brand is Wegovy, not Ozempic. Paying cash, the makers charge $349 to $499 for Ozempic and $299 to $699 for Zepbound by dose, and the compounded boards above show what the same molecules cost without the brand.