Are Zepbound and Mounjaro the same drug?

Yes. Both contain tirzepatide and are given as one weekly subcutaneous injection. The difference is the approved indication and the packaging.

Which lasts longer, the pen or the vial?

Both pens hold four weekly doses. Mounjaro's label says to discard the pen 30 days after first use and to keep it below 30 °C once unrefrigerated.

Do I need to step up from one to the other?

No. Switching brands does not change the molecule. Dose changes follow your prescriber's schedule, not the product name.

Do the pens come with needles?

Zepbound's KwikPen ships with needles. Mounjaro's pen does not include them, so you need a separate supply.

Zepbound (tirzepatide) vs Mounjaro (tirzepatide) injection

Q: Which is better for weight loss?

Zepbound is the version approved for chronic weight management. Mounjaro is approved for type 2 diabetes, though it contains the same active ingredient.

Zepbound and Mounjaro are the same drug: tirzepatide, given as one weekly subcutaneous shot in a four-dose pen. The difference is the label, not the molecule. Zepbound is FDA-approved for chronic weight management; Mounjaro is approved for type 2 diabetes. Both are brand-name, both come from Eli Lilly, and neither is a generic. Pick by your diagnosis and what your insurance or clinic covers, not by the name on the box.

Choose the Zepbound if your goal is weight loss and your prescriber is treating obesity rather than diabetes.
Choose the Mounjaro if you have type 2 diabetes and your care is built around blood sugar control.

Prices

Zepbound (tirzepatide): $25.00 at Amazon (checked today)
Mounjaro (tirzepatide) injection: $25.00 at Amazon (last seen Nov 9)
Difference: both cost the same at the latest prices (Nov 9 and Nov 11)