Zepbound vs Mounjaro — same drug, same dose

Eli Lilly developed tirzepatide as a dual agonist — a new mechanism that targets both GLP-1 and GIP receptors. The company first pursued FDA approval for type 2 diabetes (Mounjaro) and later conducted trials for weight loss, securing a separate FDA approval (Zepbound).

Both brands are made by Eli Lilly from the same active ingredient at the same maximum dose (15mg weekly). What differs is the FDA label and indication:

• •FDA approval: Mounjaro for diabetes, Zepbound for weight loss
• •Insurance coverage: Each brand covered for its approved use only
• •Clinical evidence: Different trials with different populations

Unlike Wegovy vs Ozempic, Zepbound and Mounjaro reach the same maximum dose: 15mg weekly. You might expect this to mean they produce identical weight loss results. But they don't — and here's why:

So the comparison is straightforward: tirzepatide 15mg in non-diabetics produces ~20% weight loss (Zepbound trials). The same drug at the same dose in people with diabetes produces ~13% (Mounjaro trials). The drug is identical; the bodies responding to it are different.

Since both drugs reach the same 15mg dose, some people wonder if they can use Mounjaro (diabetes brand) for weight loss and expect similar results to Zepbound. Insurance coverage tells the real story:

• 1.Mounjaro is labeled for diabetes. Using it for weight loss without diabetes is an off-label use.
• 2.Insurance covers approved indications. Most insurance plans cover Mounjaro for type 2 diabetes but not off-label for weight loss in non-diabetics.
• 3.Zepbound is the approved option. If you have obesity or overweight with a condition, Zepbound is FDA-approved for weight loss and more likely to be covered.

Eli Lilly publishes a list price for each brand, and sells both self-pay through its LillyDirect program:

What you actually pay depends on your insurance, your dose, and which form (pen or vial) is prescribed.

This depends on your health status and insurance: