Do You Have to Keep Mounjaro in the Fridge?

Storing your Mounjaro pen correctly helps ensure the medicine remains effective and safe to use. Here is what the product information generally covers — but always defer to your own leaflet or the electronic Medicines Compendium (eMC) for the definitive guidance on your pen.

Before first use: keep it refrigerated

Unopened Mounjaro pens are designed to be kept in the fridge at 2°C–8°C. This is the standard storage condition printed on the carton and in the patient information leaflet. Avoid storing the pen near the freezer compartment, and never freeze it — a frozen pen should not be used.

Out-of-fridge use: a limited window

Once you take a pen out of the fridge, the product information typically allows it to be kept at room temperature (generally described as up to around 30°C) for a period of time — check the leaflet that came with your pen for the precise number of days, as this can vary. If the pen has been at room temperature for longer than permitted, contact your prescriber or pharmacist before using it.

General storage tips

• Keep the pen in its original carton to protect it from light.
• Do not leave it in direct sunlight or in a hot car.
• Do not store it in a bathroom where steam and temperature changes are common.
• If you are travelling, a cool bag (not touching an ice pack directly) can help maintain the right temperature.

If you are unsure whether a pen has been stored correctly, your prescriber or pharmacist is the right person to ask. You can also read more about how to keep your Mounjaro pen and whether you need to refrigerate Mounjaro in our related guides.

Keeping on top of your pen storage is easier when you have a clear log of every dose — and that is where GLP Trackr can help. The app's dose logging feature lets you record each injection as it happens, including the date, time, and dose strength, so you always know exactly where you are in your treatment schedule and which pen you are currently using.

If you have taken a pen out of the fridge and are watching the clock on its room-temperature window, logging the date you removed it gives you a simple reference point to check back on. You can also set dose reminders so you never forget your weekly injection and end up with a pen sitting out longer than intended.

For a fuller picture of your journey — progress, how you are feeling each week, and patterns over time — the Mounjaro tracking hub brings together everything in one place. If you have ever wondered whether a pen can go back into the fridge after being left out, our guide on putting Mounjaro back in the fridge covers that question too.

Any doubts about whether your pen has been stored correctly should be directed to your prescriber or pharmacist — they can confirm whether it is still suitable to use. GLP Trackr helps you keep a clear record to support those conversations; it is not a substitute for professional advice.

Ready to keep a cleaner log of your doses and pens? GLP Trackr is free to try for 7 days — available now on the App Store and Google Play.