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Supplies · one label, read closely
The Zepbound vial and the syringe it needs
The label asks for a 1 mL syringe that can measure a 0.5 mL or 0.6 mL draw. The carton says Needles and Syringes are not included. Which of the two volumes applies depends on whether your vial is single-dose or multi-dose.
Source: Eli Lilly label for Zepbound, read 2026-08-13
What matters first
This is a reading of the label, not a set of instructions. The label’s own steps are the instructions, and whoever prescribed the vial is who shows you them. What is missing from the label is what those volumes look like on a barrel, and that is what this page adds.
What the label actually specifies
One sentence, in the section written for prescribers. It is more specific than any other GLP-1 label on this point, and it is still only about the barrel.
“Instruct patients using ZEPBOUND vials to use a syringe appropriate for dose administration (e.g., a 1 mL syringe capable of measuring a 0.5 mL or 0.6 mL dose) and always use a new syringe and needle for each injection.”
Three things are settled by that sentence: a 1 mL barrel, a draw of 0.5 mL or 0.6 mL, and a new syringe and needle every time. Nothing about gauge or length is settled anywhere on the document.
Two vials, two volumes
Zepbound ships in a single-dose vial and a multi-dose vial, and the draw is different. Reading the wrong figure off the wrong page is the mistake this section exists to catch.
Single-dose vial
| Barrel | 0.5 mL reads as | Fits |
|---|---|---|
| U-100 | 50 marks | Yes |
| U-50 | 50 marks | Yes |
| U-40 | 20 marks | Yes |
Multi-dose vial
| Barrel | 0.6 mL reads as | Fits |
|---|---|---|
| U-100 | 60 marks | Yes |
| U-50 | 60 marks | No |
| U-40 | 24 marks | Yes |
Note the U-40 row on both. The same liquid reads as far fewer marks there, because each mark holds two and a half times as much. So a barrel reading 60 is not the same instruction on every syringe. On a U-40 it is a very different amount of liquid.
How long the vial lasts once it is open
The single-dose vial is finished after one use, with anything left over thrown away. The multi-dose vial runs 30 days from first use, or four weekly doses, whichever comes first.
Both of those numbers come from the Zepbound label, not from the water and not from a general rule about opened vials. That distinction matters: bacteriostatic water’s own label sets no clock at all after first puncture, so any day count you are working to belongs to the drug.
What the bacteriostatic water label does and does not say about that
Next
- ZEPBOUND (tirzepatide) injection — Eli Lilly and Company (DailyMed SPL)retrieved 2026-08-13FDA label