Drug facts

Mounjaro, Zepbound and tirzepatide

Reviewed August 2026

Quick answer

They are the same molecule. Tirzepatide is the drug; Mounjaro and Zepbound are the two FDA-approved products that contain it, both from Eli Lilly. What separates them is the condition each is approved to treat — not the strength, not the schedule, and not the ingredient.

One molecule, two names1

Both products are registered to the same manufacturer and both list tirzepatide as their single active ingredient. If you have been told you are taking “Mounjaro” and elsewhere seen the same thing called “tirzepatide”, nothing has changed — one is the brand and the other is the drug.

What actually differs2

The approved indication. Mounjaro is approved to improve blood sugar control in adults with type 2 diabetes. Zepbound is approved for chronic weight management, and separately for moderate-to-severe obstructive sleep apnea in adults with obesity.

What follows from that. Insurance treats them differently, because they are prescribed for different conditions; the direct-purchase prices differ; and the labels carry the warnings relevant to their own populations — the diabetes label discusses hypoglycemia in combination with insulin or a sulfonylurea, which is not a concern the weight-management population usually has.

One documented label difference worth knowing: the suicidal behavior and ideation warning that FDA asked to be removed in early 2026 had only ever sat on the weight-management labels, including Zepbound’s. Mounjaro’s never carried it. What the labels say about mood →

What does not differ2

The active ingredient. The manufacturer. The dose range — 2.5 mg to a maximum of 15 mg once weekly, in 2.5 mg steps no sooner than four weeks apart, on both. The boxed warning about thyroid C-cell tumors, which attaches to the molecule and therefore to both. The dosing schedule →

So “is one stronger than the other” has a flat answer: no. A 10 mg dose is a 10 mg dose.

Why two names at all3

Because a manufacturer seeking approval for a second indication generally files it as a separate product with its own label, its own trials and its own name. That is a regulatory and commercial structure, not a chemical one. It also means the two are priced, covered and prescribed separately even though a pharmacist is dispensing the same molecule.

Where compounded sits1

On the label — Mounjaro / Zepbound

Two approved products, each with a label, an FDA-reviewed manufacturing process, and trials of its own. Lilly sells Zepbound direct at $299 at the starting dose and $449 at a maintenance dose.

In a compounded vial

The same active molecule, prepared by a pharmacy, with no label of its own and no FDA review of its manufacturing. It is not a third brand and it is not a generic — there is no generic tirzepatide. Its price is set by whoever is selling it, which is why this index exists.

If you are weighing the compounded market against buying the approved product directly, we keep that comparison current: is compounded still cheaper?

Questions

Is Mounjaro the same as tirzepatide?
Mounjaro is a brand name for tirzepatide. Tirzepatide is the drug; Mounjaro is one of the two FDA-approved products that contain it, and Zepbound is the other. Both are made by Eli Lilly.
What is the difference between Mounjaro and Zepbound?
The approved indication, and almost nothing else about the molecule. Mounjaro is approved to improve blood sugar in type 2 diabetes; Zepbound is approved for chronic weight management and for obstructive sleep apnea in adults with obesity. Same active ingredient, same manufacturer, same dose range of 2.5 mg to 15 mg once weekly.
Is one stronger than the other?
No. Both are dosed from 2.5 mg to a maximum of 15 mg once weekly, in 2.5 mg steps no closer than four weeks apart. A 10 mg dose of one is a 10 mg dose of the other.
Is compounded tirzepatide the same as Mounjaro?
No. A compounded preparation contains the same active molecule but is not an FDA-approved product: it has no label of its own, has not been through FDA review for safety, effectiveness or manufacturing quality, and its concentration and expiry are set by the compounding pharmacy rather than by an approved label.

Sources

  1. DailyMed SPL records for MOUNJARO (set d2d7da5d-ad07-4228-955f-cf7e355c8cc0) and ZEPBOUND (set 487cd7e7-434c-4925-99fa-aa80b1cc776b), both Eli Lilly and Company DailyMed
  2. FDA prescribing information for MOUNJARO and ZEPBOUND (tirzepatide), sections 1, 2 and 5, both revision 4/22/2026 DailyMed
  3. Compounded Tirzepatide editorial policy and medical disclaimer — this section states our own position and makes no claim from the label Read it