What's the difference between Mounjaro and Zepbound?

They're the same medication — tirzepatide — under two brand names. Mounjaro is approved for type 2 diabetes; Zepbound is approved for weight management and obstructive sleep apnea. In some countries outside the U.S., Mounjaro is used for both diabetes and weight management.

What is tirzepatide approved to treat?

In the U.S.: type 2 diabetes (Mounjaro, in adults and children 10+), chronic weight management (Zepbound, for obesity or overweight with a related condition), and moderate-to-severe obstructive sleep apnea in adults with obesity (Zepbound).

How is tirzepatide different from semaglutide?

Tirzepatide is a 'dual agonist' — it activates two gut-hormone receptors, GIP and GLP-1 — while semaglutide targets only GLP-1. That second target tends to make tirzepatide more effective on average for weight loss.

Is tirzepatide approved for heart disease or fatty liver?

Not yet. As of 2026 it's being studied for heart failure and metabolic liver disease (MASH), and it does not yet carry an FDA cardiovascular indication (unlike semaglutide). Those are investigational uses — your prescriber is the source of truth.

Tirzepatide

Tirzepatide is Eli Lilly's once-weekly dual GIP/GLP-1 receptor agonist, sold as Mounjaro (type 2 diabetes) and Zepbound (weight management and obstructive sleep apnea). Here's its history, what it's approved and being studied for, and how the two brand names map to its uses.

Updated Jul 15, 2026

Tirzepatide is a once-weekly injectable and the first of a class of "dual agonists" — it activates two gut-hormone receptors, GIP and GLP-1, rather than GLP-1 alone. It's made by Eli Lilly and sold under two different brand names depending on what it's prescribed for.

The different product names

Mounjaro — the brand approved for type 2 diabetes.
Zepbound — the brand approved for weight management and, more recently, obstructive sleep apnea.
Tirzepatide is the generic (drug) name shared by both.

Same molecule, different box. In the U.S. the two brand names track the two approved uses. Outside the U.S., the Mounjaro brand is used for both diabetes and weight management in some markets, and the Zepbound name may not appear at all.

Timeline

May 2022 — FDA approves Mounjaro for type 2 diabetes in adults, the first dual GIP/GLP-1 agonist to reach the market. (Its diabetes trials ran under the SURPASS program.)
2022 — SURMOUNT-1, the pivotal obesity trial, is published, showing roughly 20% average weight loss. (The obesity program is SURMOUNT.)
November 8, 2023 — FDA approves Zepbound for chronic weight management.
December 20, 2024 — FDA approves for moderate-to-severe in adults with obesity — the first medication ever approved for OSA.

tirzepatidemounjarozepbounddual-agonisteli-lillytreatment

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Common questions

Questions people often ask about this topic.

What's the difference between Mounjaro and Zepbound?
They're the same medication — tirzepatide — under two brand names. Mounjaro is approved for type 2 diabetes; Zepbound is approved for weight management and obstructive sleep apnea. In some countries outside the U.S., Mounjaro is used for both diabetes and weight management.
What is tirzepatide approved to treat?
In the U.S.: type 2 diabetes (Mounjaro, in adults and children 10+), chronic weight management (Zepbound, for obesity or overweight with a related condition), and moderate-to-severe obstructive sleep apnea in adults with obesity (Zepbound).
How is tirzepatide different from semaglutide?
Tirzepatide is a 'dual agonist' — it activates two gut-hormone receptors, GIP and GLP-1 — while semaglutide targets only GLP-1. That second target tends to make tirzepatide more effective on average for weight loss.
Is tirzepatide approved for heart disease or fatty liver?
Not yet. As of 2026 it's being studied for heart failure and metabolic liver disease (MASH), and it does not yet carry an FDA cardiovascular indication (unlike semaglutide). Those are investigational uses — your prescriber is the source of truth.

Evidence: For & Against

Both sides of the topic, so you can weigh the evidence yourself.

4Supporting

FDA Approves New Medication for Chronic Weight Management (Zepbound) (external link)
U.S. Food and Drug Administration · Reporting
FDA announcement of the November 2023 Zepbound approval for chronic weight management — supports the timeline and the weight-management indication.
FDA approves Zepbound (tirzepatide) as the first and only prescription medicine for moderate-to-severe obstructive sleep apnea in adults with obesity

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