Short answer: Keep Mounjaro in the fridge at 36-46°F (2-8°C) in its carton. A single-dose pen or vial may be kept unrefrigerated, not above 86°F (30°C), for up to a total of 21 days. A KwikPen or multi-dose vial is thrown away after 30 days at room temperature, 30 days after first use, or 4 weekly doses, whichever comes first. Never use it if frozen.
| Form | Storage | Limit |
|---|---|---|
| Single-dose pen or single-dose vial | Refrigerator 36-46°F (2-8°C); if needed, unrefrigerated not above 86°F (30°C) | Discard after a total of 21 days at room temperature |
| Multi-dose vial or KwikPen, unopened | Refrigerator until the expiration date | If kept at room temperature (up to 86°F), throw away after 30 days |
| Multi-dose vial or KwikPen, in use | Refrigerator or room temperature up to 86°F (30°C), in the carton | Throw away after 30 days at room temperature, 30 days after first use, or 4 weekly doses |
For every form, section 16.2 says: “Do not freeze MOUNJARO. Do not use MOUNJARO if frozen. Protect MOUNJARO from heat and light.”
The 21 days for a single-dose pen or vial is a running total. Time out of the fridge adds up: three days on a trip and four days on the counter count as seven of the 21. Once the total reaches 21 days, the label says discard it.
The KwikPen has three clocks and whichever runs out first wins: 30 days after first use, 30 days total at room temperature, or 4 weekly doses. The KwikPen Instructions for Use say the pen “will prevent you from dialing a full dose after you have given yourself 4 weekly doses” and not to transfer Mounjaro into a syringe.
Single-dose vials: “Throw away all opened vials after use, even if there is medicine left in the vial” (Instructions for Use). See the Mounjaro guide and the tirzepatide page.
Frozen: the pen Instructions for Use say “If the Pen has been frozen, throw the Pen away and use a new Pen.” Do not use it if it is cloudy, discolored or has particles; it should be colorless to slightly yellow.
Too warm: the room-temperature allowance is capped at 86°F (30°C). The label gives no allowance above that. You do not need to warm a pen before injecting; the Instructions for Use say “It is not necessary to warm the Pen to room temperature.”
A single-dose Mounjaro pen can travel unrefrigerated, not above 86°F (30°C), as long as its total time out of the fridge stays under 21 days. Write down the days so the total is easy to add up.
More in the travel guide.