Mounjaro must be kept cold. Storing it incorrectly can stop the medication working.
Unopened pens
- Store in the fridge at 2°C to 8°C
- Keep in the original carton to protect from light
- Do not freeze. Frozen pens must not be used
- Avoid storing near the back of the fridge or against the wall, where temperatures can drop below freezing
Once you've started using a pen
- You can keep it at room temperature (below 30°C) for up to 21 days
- Or continue to store it in the fridge — your choice
- Keep the cap on between injections to protect from light
- Discard after 21 days at room temperature even if there's medication left
Travelling with your medication
- Use a cool bag with ice packs for longer journeys
- Always carry it in hand luggage when flying — never in the hold, which can freeze
- Take a copy of your prescription paperwork when travelling abroad
If your medication has been stored incorrectly
Do not use a pen that has been frozen, exposed to high heat, or left at room temperature for more than 21 days. Contact our team for guidance on whether the pen is still safe to use.
If you have any concerns about your treatment, contact our support team. For medical emergencies, call 999 or 111.