Travelling with a weight loss pen
You can travel with a Mounjaro or Wegovy pen, including by air. The two things to get right are keeping it cold without letting it freeze, and carrying it in the cabin with your needles and paperwork.
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The short version
- Carry it in hand luggage, not the hold. The hold can freeze it, and freezing ruins it.
- Keep it cool but not frozen: a cool bag with a wrapped cold pack, never directly on ice.
- An in-use pen is fine below 30 °C for its in-use window (Mounjaro 30 days, Wegovy 6 weeks), so a trip usually fits.
- Bring your needles, a sharps bin and a copy of your prescription. Check your airline’s rules first.
Keep it cold, but do not freeze it
These pens live in the fridge at 2 to 8 °C, but once in use they can be kept below 30 °C for a set time (see how to store your pen for the exact days). For a journey, a small cool bag with a cold pack is enough. Wrap the cold pack in a cloth so the pen does not touch it, because a pen that freezes must be thrown away even after it thaws. Do not leave it in a hot car or in direct sun either: above 30 °C the dose can no longer be relied on.
Flying with it
- Put the pen and needles in your hand luggage. The hold is not temperature controlled and can go below freezing.
- Keep everything in its original packaging with the pharmacy label.
- Carry a copy of your prescription or a letter from your prescriber, in case security asks.
- Take a sharps bin for used needles, and enough needles for the trip.
- Airport and airline rules differ, so check your carrier before you travel, especially for cool bags and cold packs.
When you arrive
Put the pen back in a fridge as soon as you can. If the pen stayed below 30 °C the whole time, you are still inside its in-use window, so just keep counting the days. If it may have frozen or got hot, do not use it. The storage checker will give you a straight keep or bin answer for what happened.
Common questions
- Can I take my pen and needles through airport security?
- Yes. You can carry injectable medicines and needles in hand luggage. Keep them in the original packaging with the pharmacy label, and carry a copy of your prescription or a letter from your prescriber. Rules vary by airport and airline, so check your carrier before you fly.
- Should my pen go in the hold or in hand luggage?
- Hand luggage. The hold is not temperature controlled and can drop below freezing, which ruins the medicine, and a checked bag can also go missing. Keeping it with you also keeps it inside its temperature range.
- How long can it be out of the fridge while I travel?
- Once a pen is in use it can be kept below 30 °C for a set number of days (Mounjaro 30 days, Wegovy 6 weeks), which usually covers a trip. Keep it cool but not frozen, and refrigerate it again when you arrive.
- What if my pen freezes or gets hot on the journey?
- A pen that has been frozen must not be used, even after it thaws. A pen that got hot, above 30 °C, should be replaced because the dose can no longer be relied on. If you are not sure, check it on the storage tool.
Sources
Temperature limits are from each product’s UK SmPC as of 3 November 2026. Airport and airline rules change and differ by carrier, so confirm them yourself before you travel. This is general guidance, not medical advice.