Yes — store unopened Mounjaro in the refrigerator (36°F–46°F (2°C–8°C) in original carton until use). Once you start a pen, it can stay at room temperature: Up to 21 days at room temperature (≤86°F / 30°C) Discard pen 21 days after first use
Storage & timing for Mounjaro
Practical handling guidance. Always follow the dispensed label.
Before use
36°F–46°F (2°C–8°C) in original carton until use
At room temperature
Up to 21 days at room temperature (≤86°F / 30°C)
After first use
Discard pen 21 days after first use
When to inject
Any time of day, with or without food. Same day each week.
If you miss a dose
Take the missed dose as soon as possible within 4 days (96 hours) after the missed dose. If more than 4 days have passed, skip it and take the next dose on the regularly scheduled day. Never take two doses within 3 days (72 hours) of each other.
Does Mounjaro need to be refrigerated?
Before you open it, yes — keep Mounjaro refrigerated at 36°F–46°F (2°C–8°C) in original carton until use. Do not freeze it; a pen that has frozen should not be used even after thawing. After first use, most people can keep the pen at room temperature: Up to 21 days at room temperature (≤86°F / 30°C) Track the date you first used it so you know when to discard: Discard pen 21 days after first use
What if Mounjaro was left out of the fridge?
An unopened pen left at room temperature is generally still usable within the room-temperature window on the label (up to 21 days at room temperature (≤86°f / 30°c)), but once that window is exceeded — or if it was exposed to heat above the labeled limit or to freezing — it should not be used. If you are unsure how long it sat out or how warm it got, call your pharmacist before injecting; do not guess. Never use a pen that has been frozen.
Traveling with Mounjaro
For trips, carry Mounjaro in an insulated bag with a cold pack (not directly touching the pen, to avoid freezing) and keep it in your carry-on, never a checked bag or a hot car. At your destination, refrigerate any unopened pens. Airport security allows medically necessary medication and cold packs; a pharmacy label or prescription can smooth the screening.
When to take Mounjaro
Any time of day, with or without food. Same day each week. If you miss a dose: Take the missed dose as soon as possible within 4 days (96 hours) after the missed dose. If more than 4 days have passed, skip it and take the next dose on the regularly scheduled day. Never take two doses within 3 days (72 hours) of each other.
Common questions
Does Mounjaro need to be refrigerated?
Unopened Mounjaro is kept in the refrigerator (36–46°F / 2–8°C). Its label then allows a defined stretch outside it: up to 21 days total at room temperature, then discard. Never freeze an injectable pen; if it freezes, do not use it.
How long can Mounjaro stay out of the fridge?
Up to 21 days total at room temperature, then discard, per the Mounjaro label (single-dose pen or single-dose vial). Limits differ by drug — Trulicity allows 14 days, the tirzepatide single-dose pens 21, a Wegovy pen 28 out of the fridge, and an Ozempic pen 56 from first use — so do not carry a figure over from a previous medication. If you are unsure how long yours sat out, ask your pharmacist before using it.
Can I travel with Mounjaro?
Yes. Carry Mounjaro in an insulated bag with a cold pack (not touching the pen, to avoid freezing) in your carry-on — never a checked bag or a hot car. Refrigerate unopened pens at your destination. Airport security permits medically necessary medication and cold packs; keeping the pharmacy label or prescription handy helps at screening.
Is Mounjaro still good if it was left out overnight?
Often yes, if it stayed within the labeled room-temperature window and didn't get too hot or freeze — but check the number of days your product allows at room temperature and how warm it got. When in doubt, call your pharmacist rather than guessing. Never use a pen that has frozen, even once.