Two summers ago a patient of mine drove from Phoenix to San Diego with a month of Zepbound in the boot. It was 41 degrees outside. She arrived with four pens that looked completely normal and were, in every way that mattered, no longer medication.
Nothing about a degraded peptide is visible. That is the entire problem with travel.
The three numbers
| Product | Unopened | Room temperature once in use |
|---|---|---|
| Ozempic | Fridge 2–8°C | Up to 30°C for 56 days |
| Wegovy | Fridge 2–8°C | Up to 30°C for 28 days |
| Mounjaro | Fridge 2–8°C | Up to 30°C for 21 days |
| Zepbound | Fridge 2–8°C | Up to 30°C for 21 days |
Two things follow from that table.
The first is that a two-week holiday needs no refrigeration at all for any of these products. People carry cool bags around Europe unnecessarily.
The second is that tirzepatide has the tightest window, at three weeks. If you are on Mounjaro or Zepbound and travelling for a month, you need a plan.
Flying
Hand luggage, always. Hold temperatures on a long flight can drop well below freezing. Checked bags also go missing, and replacing a GLP-1 prescription in an unfamiliar country over a weekend is a genuinely difficult afternoon.
TSA rules are more accommodating than people expect. Injectable medication, pen needles and ice packs are all permitted in carry-on. Medically necessary liquids exceed the usual limits legitimately. You must declare them at the checkpoint, and it is smoother if they are out of your bag before you are asked.
Keep the original carton. The pharmacy label on the box is what turns a bag of syringes into an obvious prescription. This matters more at international borders than domestic ones — some countries take a considerably dimmer view of undeclared injectables, and a few require documentation for controlled or prescription-only medicines.
Bring a copy of the prescription or a short letter from your prescriber for international travel. It weighs nothing and occasionally saves an hour.
Sharps. Bring a small travel sharps container or a hard-sided case. Do not improvise with a hotel water bottle and do not leave used needles in a bin for housekeeping.
2–8°C
Refrigerated storage range for all unopened pens
30°C
Maximum room temperature during the in-use window
0°C
The temperature at which a pen becomes unusable, permanently
Cooling, for when you actually need it
If your trip is longer than the in-use window, or you are somewhere routinely above 30°C, you need active cooling.
Evaporative cooling wallets — Frio is the best known — use water rather than ice and hold roughly 18–26°C for a couple of days per soak. They are excellent for hot climates and useless in humid ones, since evaporation is the mechanism.
Insulated cases with gel packs — 4AllFamily and Medactiv make ones designed for pens. These hold true refrigeration temperatures longer, at the cost of bulk and needing a freezer to recharge.
The failure mode to avoid with both is over-cooling. A gel pack straight from a freezer, pressed against a pen, will freeze it. Wrap the pack, or keep a layer between it and the medication.
For hotel fridges: minibar fridges are frequently colder than they claim and often have a freezing coil at the back. Put the pen in the door, not against the back wall, and check it.
Time zones and your injection day
Weekly dosing is forgiving in a way daily dosing is not. Crossing time zones does not require any adjustment — take the dose on your usual day, at whatever hour is convenient locally.
If the trip means shifting your injection day, the same rules apply as at home: at least 48 hours between doses for semaglutide, at least 72 hours for tirzepatide. Move the day once, deliberately, rather than drifting.
A missed week abroad is not a crisis. Semaglutide can be taken up to five days late, tirzepatide up to four; past that, skip it and resume on schedule. The detail is in what to do about a missed dose.
Nothing about a degraded pen looks different. Which is why the temperature rules are worth following exactly rather than approximately.
The practical packing list
- Pens in original cartons, in hand luggage
- One spare pen beyond what the trip requires, if your supply allows it
- Fresh needles, more than you need, plus a travel sharps container
- Alcohol swabs
- A cooling case only if the trip exceeds the in-use window or the climate demands it
- A photograph of your prescription on your phone
- Anti-nausea supplies, because unfamiliar food and a dose increase are a poor combination
The spare pen is the item people skip and regret. Given how routinely supply has been unpredictable, arriving somewhere unfamiliar one pen short is a worse position than it sounds.
Heat at the destination is its own problem — poolsides, parked cars, saunas and hot tubs are covered in saunas, hot tubs and heat.
The short version
Hand luggage. Original box. Never frozen, never above thirty. Twenty-one days for tirzepatide, longer for semaglutide.
Everything else about travelling on these drugs is ordinary travel, with slightly better snacks planning.