Peptide Label TemplateMulti Dose Vial Expiration
Multi dose vial expiration works on two clocks. Before you open the vial, the maker's printed date applies. Once you open it, the CDC says to date the vial and throw it out within 28 days, unless the maker gives a different date.
Three dates that can apply
| Date | Where it comes from | When it applies |
|---|---|---|
| Printed expiration date | The maker, on the vial or box | Always. Never use a vial past this date |
| 28 days after opening | The CDC rule for opened multi-dose vials | Once the stopper has been pierced, unless the maker says otherwise |
| The maker's opened date | The maker's label or leaflet, if it gives one | Instead of the 28 days, when the maker sets a date for an opened vial |
The rule of thumb is simple. Use the maker's opened date if it gives one, and 28 days if it does not. The CDC also says the discard date for an opened vial must never be later than the maker's original expiration date.
What the 28 day rule means
A multi-dose vial is made to be used more than once, and it usually has a preservative in it. Each time a needle goes through the stopper, germs could get in, which is why health groups set a limit on how long an opened vial stays in use.
The CDC rule reads like this, in plain words: once a multi-dose vial is opened, date it, and throw it out within 28 days. The only exception is when the maker states another date for the opened vial.
A summary from ASHP, the national group for hospital pharmacists, lines up the same 28 day limit across the CDC, Medicare rules, The Joint Commission and the USP 797 standard. Its last update was September 2025.
The 28 days is a limit on how long to use an opened vial. It is not a promise about what is in the vial, or that it is still good up to that day.
Single-dose vials are different
A single-dose vial is meant for one person and one use. The CDC says not to save what is left in it or mix leftovers from different vials. So a single-dose vial does not get a 28 day date at all.
Work out the discard date
Pick the day the vial was first opened. The helper adds 28 days.
Discard date helper
Adds 28 days to the day the vial was first opened. If the maker gives its own date for an opened vial, use that date, and never go past the printed expiration date.
Discard by:
If the maker gives its own date for an opened vial, write that date instead. If the printed expiration date comes first, write that one.
What to write on the label
A short label is easier to read. For an opened multi-dose vial, write at least these two dates:
- Opened: the day the stopper was first pierced.
- Discard by: the day it must be thrown out. This is also called the beyond-use date.
The label maker has both boxes. When you set the date opened, it fills in the discard date 28 days later. You can type over it if the maker gives its own date, or if the printed expiration date comes first. For the rest of the label, such as a name and lot number, see the peptide vial labels guide. To pick a label that fits, see the 3ml vial label size guide.
Frequently asked questions
When does a multi-dose vial expire?
An unopened vial expires on the date the maker printed. After it is opened, the CDC says to throw it out within 28 days, unless the maker gives another date. If the printed date comes before that, the printed date wins.
What is the 28 day rule for multi-dose vials?
It is a CDC rule for vials that have been opened. You date the vial when you open it. Then you throw it out within 28 days, unless the maker states a different date.
What is a beyond-use date?
It is the last day an opened or mixed product should be used. For an opened multi-dose vial, it is usually 28 days after opening. It can never be later than the maker's printed expiration date.
What goes on a beyond-use date label?
Write the discard date itself, not just the day the vial was opened. Many people also write the date opened, so both are easy to check. A name for the vial helps too, so you know which one the dates belong to.
Can a multi-dose vial be used past the maker's expiration date?
No. The CDC says the date for an opened vial must never go past the maker's original expiration date. If that printed date comes first, it wins.
What is a multi-dose vial?
It is a vial made to hold more than one dose, so it can be opened more than once. It usually contains a preservative. A single-dose vial, by contrast, is for one use only.
Sources
- CDC injection safety guidance for health care providers, CDC, page updated 26 March 2024, read 2026-10-05
- Crosswalk of Guidances and Standards for Managing Single and Multi-Dose Vials, ASHP, revised September 2025, page 4, read 2026-10-05