At a glance
| Mark on U-100, 1 mL | Volume | at 4.17 mg/mL Zepbound 10 mg multi-dose vial | at 5 mg/mL Zepbound 2.5 mg single-dose vial | at 8.33 mg/mL Zepbound 20 mg multi-dose vial | at 10 mg/mL Zepbound 5 mg single-dose vial | at 12.5 mg/mL Zepbound 30 mg multi-dose vial | at 16.7 mg/mL Zepbound 40 mg multi-dose vial | at 20 mg/mL Zepbound 10 mg single-dose vial | at 25 mg/mL Zepbound 12.5 mg single-dose vial and 60 mg multi-dose vial |
|---|---|---|---|---|---|---|---|---|---|
| 10 units | 0.1 mL | 0.417 mg | 0.5 mg | 0.833 mg | 1 mg | 1.25 mg | 1.67 mg | 2 mg | 2.5 mg |
| 20 units | 0.2 mL | 0.834 mg | 1 mg | 1.67 mg | 2 mg | 2.5 mg | 3.34 mg | 4 mg | 5 mg |
| 25 units | 0.25 mL | 1.04 mg | 1.25 mg | 2.08 mg | 2.5 mg | 3.13 mg | 4.17 mg | 5 mg | 6.25 mg |
| 30 units | 0.3 mL | 1.25 mg | 1.5 mg | 2.5 mg | 3 mg | 3.75 mg | 5.01 mg | 6 mg | 7.5 mg |
| 40 units | 0.4 mL | 1.67 mg | 2 mg | 3.33 mg | 4 mg | 5 mg | 6.68 mg | 8 mg | 10 mg |
| 50 units | 0.5 mL | 2.08 mg | 2.5 mg | 4.17 mg | 5 mg | 6.25 mg | 8.35 mg | 10 mg | 12.5 mg |
| 60 units | 0.6 mL | 2.5 mg | 3 mg | 5 mg | 6 mg | 7.5 mg | 10.02 mg | 12 mg | 15 mg |
Arithmetic at the concentrations shown. The concentration on your own label is the one that counts; enter it in the calculator.
Why the milligrams depend on the vial
10 units is a tenth of a millilitre. On its own that is all a syringe mark can tell you; the milligrams come from the vial. At the Zepbound concentrations, 0.1 mL is 0.42 mg from the 10 mg multi-dose vial, 0.5 mg from the 2.5 mg single-dose vial, 0.83 mg from the 20 mg multi-dose vial, 1 mg from the 5 mg single-dose vial, and so on up to 3 mg from the 15 mg single-dose vial. None of those is a labelled Zepbound dose. The label describes drawing the whole single-dose vial, 50 units, or 0.6 mL, 60 units, from a multi-dose vial. A 10-unit instruction for tirzepatide therefore usually comes from a compounded vial, where the pharmacy set the concentration and wrote the mark to match. Use that pharmacy's mg/mL, not a Zepbound figure, to know what 10 units holds.
The mistake to watch for. Ten units is a small draw on a 1 mL syringe, and the marks are every two units. The 0.5 mL and 0.3 mL syringes show the same 10 units at a more readable spacing. The volume, and the dose, are identical; only the readability changes.