Drug facts
Compounded tirzepatide vs Zepbound
Reviewed August 2026
Quick answer
Both contain tirzepatide. Only Zepbound and Mounjaro are FDA-approved products with a reviewed label, reviewed manufacturing, and trial data behind them. A compounded preparation is made for an individual patient and has none of those three things — which is a statement about what has been reviewed, not a claim that it does not work.
Only two tirzepatide products hold an FDA label1
Mounjaro, approved for type 2 diabetes, and Zepbound, approved for chronic weight management. Both are made by Eli Lilly. Everything else listed as a tirzepatide product in the federal labeling database is repackaged Mounjaro.
That is the fact the rest of this page rests on, and it is why this section of the site exists: when people ask what the label says about compounded tirzepatide, the accurate answer is that there is no such label, and the approved product’s label is the closest thing available.
What is the same1
The active molecule, and therefore the mechanism — tirzepatide acts at both the GIP and GLP-1 receptors. The boxed warning attaches to the molecule, so it applies either way, as do the contraindications. See the boxed warning.
What is different1
On the label — Mounjaro / Zepbound
Approval. Reviewed and approved by FDA for a stated indication.
In a compounded vial
Not FDA-approved. Compounded preparations are not reviewed for safety, effectiveness or quality before they reach a patient.
On the label — Mounjaro / Zepbound
Strength. Fixed, standardized, and identical between boxes.
In a compounded vial
Concentration is set by the pharmacy and varies between sellers, which is why a dose in milligrams is a different mark on the syringe from a different vial. See units and milligrams.
On the label — Mounjaro / Zepbound
Dating. An expiration date backed by stability data FDA reviewed.
In a compounded vial
A beyond-use date assigned by the pharmacy, usually much shorter, and varying between pharmacies. See storage and beyond-use dating.
On the label — Mounjaro / Zepbound
Evidence. Randomized trials in tens of thousands of participants, published and reviewed.
In a compounded vial
No trial has studied a compounded preparation. The evidence people cite for compounded tirzepatide is evidence about the approved product.
What that last one really means1
It is not a claim that compounded tirzepatide does not work. The molecule is the molecule. It is a narrower and more precise point: every efficacy figure you will see quoted — the weight-loss percentages, the trial names — was produced using the approved product, and nothing has tested whether a given pharmacy’s preparation delivers the same thing.
Which is exactly why the pharmacy behind a seller, and what it will tell you about concentration and dating, is worth more attention than the number on its landing page.
And the price2
The reason anyone weighs this trade-off is cost. What the compounded market actually charges per month — as opposed to what it advertises — is the index.