Mounjaro vs Zepbound: One Drug, Two Labels
Mounjaro (tirzepatide, Eli Lilly) vs Zepbound (tirzepatide, Eli Lilly)
Last verified May 2026
The verdict
One molecule, one dose ladder, one maker, sold twice under two names. Diabetes sits on the Mounjaro label; obesity and sleep apnea sit on Zepbound's. Pricing is identical at $349 starter and $499 maintenance for vials. The practical difference is which label your prescription is written against, because that is what decides coverage. Nothing pharmacological separates them, and any page implying otherwise is selling something.
Side-by-side comparison
| Field | Mounjaro | Zepbound |
|---|---|---|
| Active ingredient | Tirzepatide | Tirzepatide |
| FDA-labeled indication | Type 2 diabetes mellitus | Chronic weight management; obstructive sleep apnea (Dec 2024) |
| Pivotal trial weight-loss anchor | −11.2 kg / 40 weeks (SURPASS-2, 15 mg vs semaglutide) | −20.9% TBWL / 72 weeks (SURMOUNT-1, 15 mg) |
| Mechanism | Dual GIP / GLP-1 receptor agonist | Dual GIP / GLP-1 receptor agonist |
| Available doses | 2.5, 5, 7.5, 10, 12.5, 15 mg (pen + KwikPen + vial) | 2.5, 5, 7.5, 10, 12.5, 15 mg (pen + KwikPen + vial) |
| Cash price (LillyDirect direct-pay) | $349 starter / $499 maintenance (vial) | $349 starter / $499 maintenance (vial) |
| Commercial insurance PA criteria | A1c ≥6.5% + metformin trial; T2D benefit | BMI ≥30 (or ≥27 + comorbidity); obesity benefit (often excluded) |
| Form factor | Single-dose pen, KwikPen, single-dose vial | Single-dose pen, KwikPen, single-dose vial |
What each one costs in the compounded market
Standing monthly cash prices from the 556 sellers on this register. These are compounded preparations, not the approved products compared above.
Mounjaro — tirzepatide
from $99 /mo
253 sellers publish a standing price; the median is $240 a month.
Zepbound — tirzepatide
from $99 /mo
253 sellers publish a standing price; the median is $240 a month.
⚠ A compounded preparation is not the approved product. No agency has reviewed that specific preparation for safety, effectiveness or manufacturing quality, and the legal ground under compounding these molecules narrowed when the shortages closed. The price gap is real, and so is the difference in oversight. Every seller, with its price record.
Frequently asked questions
Are Mounjaro and Zepbound the same drug?
Chemically, yes — both are tirzepatide. They are sold under different names for different approved uses, and usually at different doses and different prices. That is a labeling and commercial distinction, not a pharmacological one, which is why a prescription for one is not automatically interchangeable with the other at the pharmacy counter.
Is Mounjaro or Zepbound cheaper?
On the manufacturers' own cash pricing: Mounjaro at $349 starter / $499 maintenance (vial), Zepbound at $349 starter / $499 maintenance (vial). ⚠ That is the list-price comparison, and it is not what most people pay. What you actually pay depends on whether your plan covers it, which formulary tier it sits in, and whether you have met your deductible — and for many people the honest comparison is between an insured copay and a cash-pay compounded alternative rather than between these two figures.
What does a compounded version of each actually cost?
Across the 556 sellers in this register, the cheapest standing monthly cash prices we hold are tirzepatide from $99 a month and tirzepatide from $99 a month. ⛔ A compounded preparation is not the approved product: no agency has reviewed that specific preparation for safety, effectiveness or manufacturing quality, and the legal ground under compounding these molecules narrowed once the shortages closed. The price gap is real and so is the difference in oversight.
Can I switch from Mounjaro to Zepbound?
People move between them regularly, since it is the same molecule — but the dose ladders differ, so a prescriber has to map where you land rather than matching the number. Do not assume your current dose transfers.
Which one should I ask for?
That is a prescriber's call, and anyone answering it from a table is guessing. What a page like this can do is tell you what the trials measured, what the manufacturers charge, and where the evidence is still missing, so the conversation starts from the record rather than from an advertisement.
References
- 1.Frías JP, Davies MJ, Rosenstock J, et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2). N Engl J Med. 2021. PMID: 34170647.
- 2.Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). N Engl J Med. 2022. PMID: 35658024.
- 3.Malhotra A, Grunstein RR, Fietze I, et al. Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity (SURMOUNT-OSA). N Engl J Med. 2024. PMID: 38912654.
- 4.Eli Lilly and Company. Mounjaro (tirzepatide) injection — FDA prescribing information. DailyMed. 2025. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=d2d7da5d-ad07-4228-955f-cf7e355c8cc0
- 5.Eli Lilly and Company. Zepbound (tirzepatide) injection — FDA prescribing information. DailyMed. 2025. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=487cd7e7-434c-4925-99fa-aa80b1cc776b
- 6.Eli Lilly and Company. Zepbound SelfPay pricing — $349 starter / $499 maintenance via LillyDirect. Lilly Press Release. 2024. https://www.lilly.com/news/press-releases/lilly-launches-zepbound
Want the underlying evidence? Read our cited, in-depth evidence review →
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