Unopened tirzepatide is usable until the expiration date printed on the package when it is kept at 36°F to 46°F (2°C to 8°C), protected from light, and never frozen. This applies to FDA-approved Mounjaro and Zepbound when stored according to their product labels. This guidance reflects the U.S. labels reviewed on.
The 21-day limit applies to certain single-dose pens and vials stored at room temperature. It does not apply to unopened tirzepatide that remains properly refrigerated.
Tirzepatide Storage Times
| Tirzepatide product | Refrigerated storage | Room-temperature limit |
|---|---|---|
| Mounjaro single-dose pen or vial | Until the printed expiration date when stored correctly | Up to 21 days at or below 86°F (30°C) |
| Zepbound single-dose pen or vial | Until the printed expiration date when stored correctly | Up to 21 days at or below 86°F (30°C) |
| Unopened Mounjaro or Zepbound multi-dose vial or KwikPen | Until the printed expiration date | Discard after 30 days at room temperature |
| Opened multi-dose vial or KwikPen | Discard 30 days after first use or after 4 weekly doses, whichever comes first | Same limit |
The current U.S. labels for Mounjaro and Zepbound state that opened multi-dose vials and single-patient-use KwikPens must be discarded 30 days after first use or after four weekly doses, even if medication remains.
How Should Tirzepatide Be Stored in the Refrigerator?
Store tirzepatide:
- At 36°F to 46°F (2°C to 8°C)
- In its original carton
- Away from direct light
- Away from the freezer compartment
- Away from excessive heat
Do not use tirzepatide that has frozen. The Mounjaro and Zepbound labels instruct patients to discard frozen product.
What If Tirzepatide Was Left Out of the Refrigerator?
A single-dose Mounjaro or Zepbound pen or vial may be stored at room temperature up to 86°F (30°C) for a total of 21 days. Discard it after 21 days. Zepbound instructions also say not to return a single-dose product to the refrigerator after it has been stored at room temperature.
Do not rely on the 21-day limit if tirzepatide was exposed to temperatures above 86°F, direct sunlight, a hot car, or an unknown temperature for an unknown period. Ask a pharmacist or the manufacturer whether the product should be used.
Does Compounded Tirzepatide Last as Long as Mounjaro or Zepbound?
No. Compounded tirzepatide may have different storage instructions and a different beyond-use date. Follow the pharmacy label instead of applying the Mounjaro or Zepbound storage limits automatically.
For multi-dose compounded sterile vials, the FDA generally recommends discarding the vial within 28 days after first use, even if medication remains. A pharmacy may provide an earlier discard date. Follow the earlier date.
If compounded tirzepatide arrived warm or without adequate cooling, contact the compounding pharmacy before using it. The FDA advises patients not to use injectable compounded GLP-1 medication that arrives warm or without adequate cooling until the product's quality has been confirmed.
Bottom Line
Use the printed expiration date only when unopened tirzepatide has stayed refrigerated at 36°F to 46°F and has not frozen. Single-dose products kept at room temperature have a 21-day limit. Opened multi-dose vials and KwikPens have a 30-day or four-dose limit, whichever comes first. Compounded tirzepatide follows the pharmacy's label and beyond-use date.
If the product froze, overheated, arrived warm, or sat at an unknown temperature, check with a pharmacist, compounding pharmacy, or manufacturer before using it.