How to store Mounjaro

Mounjaro pens that are unused should be stored in a refrigerator between 2°C and 8°C before use, until you are ready for your first dose

Keeping Mounjaro at the correct temperature helps ensure the medication remains safe and effective throughout your treatment.

If you're considering treatment, you can find full details on how Mounjaro works, pricing, and eligibility on our Mounjaro injections page.

Key takeaways

• Store unused pens in the fridge – Keep your unused Mounjaro pens refrigerated between 2 and 8°C until you are ready for your first dose.
• Pens that are currently in use can be kept at room temperature – Once used for the first time, your pen can be stored either in the fridge or at room temperature (below 30°C).
• Pens last for 30 days once used – Once you have taken your first dose of a pen, it has a shelf life of 30 days. If you do not use it by then, you should throw it away, even if it has medication in it.
• Inspect your pen before using it – Your medication should be clear or have a yellow tint. If it is discoloured or has bits in it, do not use it.
• Never freeze Mounjaro – If a pen has been frozen, even by accident, do not use it. Dispose of it safely and start a new pen. It’s not likely to be effective.
• Dispose of needles properly – After using your pen, remove the needle and dispose of it in a sharps bin. Never store your pen with a needle attached.

How you should store your Mounjaro pens will depend on whether or not they are currently in use.

All unused Mounjaro medication should be stored in the fridge until it is required for use.

To store your unused Mounjaro pens, you should follow the guidance below:

• unused Mounjaro pens should be kept in the fridge between 2 and 8°C
• keep Mounjaro pens in their original, unopened packaging that clearly displays the use-by date
• avoid keeping in refrigerators that are likely to fluctuate in temperature or are at risk of failing
• do not freeze Mounjaro – if any of the pens become frozen, you must throw them away
• unused pens can be used until the expiry date printed on the label if the pen has been stored in the refrigerator

If you are currently using a Mounjaro pen, it should be stored as follows:

• keep refrigerated (although it can be kept at room temperature up to 30°C for up to 30 days)
• keep away from heat
• keep out of reach and sight of children
• dispose of the used pen 30 days after its first use or after receiving 4 weekly doses

Yes, Mounjaro must be kept in the fridge until you first use it. Once the pen is in use, you can continue to refrigerate it or it can be kept out of the refrigerator for up to 30 days but must be kept below 30°C.

It’s important that Mounjaro is kept at a consistent temperature in the fridge because fluctuating temperatures may affect its effectiveness and degrade the active ingredient, tirzepatide. If you’re worried, you might consider using a fridge thermometer to monitor the temperature, but it’s not essential.

You can ensure Mounjaro is kept at the right temperature by:

• storing the pens in their original packaging until their first use
• keeping the pens away from the freezer compartment, if you have one, to avoid freezing
• not storing the pens in the fridge door, where the temperature is likely to fluctuate most

If stored correctly, Mounjaro can last for up to 24 months in the fridge. However, you should always check the expiry date displayed on the packaging before use.

If Mounjaro is left out of the fridge for more than 30 days, used or unused, the active ingredient may start to break down, losing its effectiveness. That’s why unused pens must be kept in the fridge until their first use and in-use pens should only be left out of the fridge for a maximum of 30 days before you’ll need to safely dispose of them.

Yes, you can store your pen in the fridge, as long as it has not reached a temperature above 30°C.

If you have left a used Mounjaro pen out of the fridge overnight, it should still be fine to use as long as the temperature did not go above 30°C. Just put it back in the fridge as soon as you remember.

If it was an unopened Mounjaro pen, you’ll have 30 days to use it before it must be disposed of. This is because Mounjaro is only stable outside of the fridge for a limited time. You may still be able to use all 4 doses before discarding it, but it depends on how many doses you still have in your old pen.

The Mounjaro KwikPen has a shelf life of 24 months, so unused pens can be kept in the refrigerator up until the expiry date.

If you have already started using a Mounjaro pen it must be disposed of after 4 weekly doses and should not be used more than 30 days after its first use.

The expiry date is printed on the external packaging the Mounjaro KwikPen is supplied in. It is also clearly printed on the pen label as seen in the image below. It is important to check the expiry date on both the box and the pen before first use.

The liquid inside the Mounjaro pen should be colourless to slightly yellow. You can inspect the liquid by looking at the glass vial on the pen.

Do not use the Mounjaro pen if the liquid:

• is cloudy
• is discoloured
• has particles or debris in it
• has been frozen

If the liquid shows any of these signs, you should dispose of the pen and get a new one.

If you’re taking Mounjaro and need to travel, there are a few things you’ll need to consider before you go.

1. If you are travelling abroad, we recommend that you check the medical regulations of the country you are travelling to. Some countries do not allow certain medications into the country or restrict the amounts allowed within their borders. You might need to show documentation, like a medical certificate, to be allowed to take the medication with you. It’s best to check this before you travel to avoid any delays or confusion.
2. Before you travel, ensure you have enough Mounjaro to last for your entire trip.

If you are travelling to a different time zone, you may find it useful to set an alarm to remind you to take your medication at the usual time and on the correct day.

Yes, but only if you are travelling with an unused Mounjaro pen. Unopened Mounjaro pens should be refrigerated between 2 and 8°C to remain effective. However, they can be stored unrefrigerated provided the temperature does not go above 8°C and they are not left out of the fridge for more than 30 days. If this happens, you must throw the pens away.

If you’re only going for 2 weeks and have a used pen that contains enough doses for your holiday, you do not need to keep it cold while travelling. However, it cannot reach more than 30°C.

To store Mounjaro safely on the go, you should:

✓ travel with unopened Mounjaro in a cool bag, and transfer it into a fridge, if possible, once you reach your destination

✓ store the pen in its box to protect it from direct sunlight

✗ avoid storing Mounjaro in a bathroom or cooking area to avoid temperature changes

✗ make sure in use Mounjaro pens are not stored in direct sunlight and in temperatures above 30°C

If you are travelling for more than 30 days or have any questions about storing Mounjaro safely while you are away, contact your doctor or pharmacist for more advice.

Yes, you can take Mounjaro on a plane, but it must be stored in your carry-on luggage because the temperatures can fluctuate in the cargo hold causing the medication to freeze, which means it is no longer safe to use.

When you go through security, store your Mounjaro pen and any needles in a clear, plastic bag out of your carry-on luggage, so that it can be clearly seen and identified. If you are unsure or have any specific questions, contact your airline provider for more details.

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