How the Mounjaro (tirzepatide) prescribing information describes storage: 2 to 8 °C, the 21-day out-of-fridge window, never freeze. Not medical advice.
Key points
- 01Store unopened Mounjaro pens refrigerated at 2 to 8 °C. The Mounjaro prescribing information describes storing unopened pens and prefilled syringes refrigerated at 2 to 8 °C (36 to 46 °F) until the expiration date. Keep the device in the original carton to protect it from light.
- 02Never freeze, never store against the fridge back wall. The prescribing information describes discarding frozen Mounjaro. Freezing alters the protein structure of tirzepatide. The cold back wall and cooling element of a refrigerator can freeze the pen unintentionally.
- 03A 21-day window applies after first removal from the fridge. The Mounjaro prescribing information permits room-temperature storage up to 30 °C for up to 21 days after first removal from refrigeration. After that the device must be discarded, even if medication remains. Verify the current package insert.
- 04Mark the first-removal date on the carton. Because the 21-day window starts at first removal from the fridge and is not extended by re-refrigerating, the Instructions for Use describe writing that date down. This lets you identify the discard day reliably.
- 05Keep below 30 °C and away from direct heat. The documented upper limit is 30 °C (86 °F). A car in summer sun or a windowsill can exceed it. Sustained heat above 30 °C is the variable that pushes the device out of spec; when in doubt, discard.
- 06Let a refrigerated dose warm before injecting. The Instructions for Use describe a refrigerated dose as more uncomfortable to inject. A room-temperature dose is associated with less stinging. The out-of-fridge window permits this adjustment.
- 07Inspect the solution before every use. The Instructions for Use describe checking that the solution is clear and colorless to slightly yellow before use. Cloudy, discolored, or particulate solution is not used. Check the expiration date on the pen and carton as well.
- 08For travel, keep the pen cool and in carry-on. For trips inside the 21-day window a cooling pouch is optional, though useful in sustained heat. Keep the pen in carry-on baggage, not the hold, where it can freeze. The flying with GLP-1 medications guide covers airport security.
Frequently asked questions
Does Mounjaro need to be refrigerated?+
Unopened Mounjaro pens are stored refrigerated at 2 to 8 °C per the prescribing information. After first removal from refrigeration, the label permits room-temperature storage up to 30 °C for up to 21 days.
How long can Mounjaro be out of the fridge?+
The Mounjaro prescribing information describes a window of up to 21 days at room temperature up to 30 °C after first removal. After that the device must be discarded. The 21-day window is not extended by re-refrigerating.
Can Mounjaro be frozen?+
No. The prescribing information describes discarding frozen Mounjaro; it must not be used. Freezing alters the protein structure of tirzepatide. Do not store the pen against the cold back wall of the refrigerator.
Can I put Mounjaro back in the fridge after it has been out?+
The prescribing information describes that the pen can be re-refrigerated after first removal, but must be discarded 21 days from when it first left the fridge, regardless of how it was stored afterward. Note the first-removal date.
What if Mounjaro was stored warm for a day?+
As long as the temperature stays at or below 30 °C, the pen remains inside its documented 21-day window. Sustained heat above 30 °C is the reason to discard the device. When in doubt, contact the pharmacy or prescriber.
