The short answer
- Ozempic (in use): up to 56 days, at room temperature below 30 °C or in the fridge. Cap on, away from light.
- Mounjaro / Zepbound single-dose pens: up to 21 days unrefrigerated below 30 °C. Mounjaro KwikPen: 30 days after first use below 30 °C.
- Wegovy single-dose pens: up to 28 days between 8 and 30 °C if needed.
Storage rules by pen
| Pen |
Before first use |
Out of the fridge |
Freezing |
| Ozempic (multi-dose FlexTouch) |
Fridge 2–8 °C |
After first use: 56 days below 30 °C or in the fridge |
Don’t use if frozen |
| Wegovy (single-dose pen, US) |
Fridge 2–8 °C |
Up to 28 days at 8–30 °C before use |
Don’t use if frozen |
| Mounjaro single-dose pen (US) |
Fridge 2–8 °C |
Up to 21 days below 30 °C |
Don’t use if frozen |
| Mounjaro KwikPen (multi-dose; UK, Australia, EU) |
Fridge 2–8 °C |
30 days below 30 °C after first use |
Don’t use if frozen |
| Zepbound single-dose pen / vial |
Fridge 2–8 °C |
Up to 21 days below 30 °C |
Don’t use if frozen |
| Rybelsus (oral semaglutide tablets) |
Room temperature in the blister |
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These are the manufacturers’ limits; follow the leaflet in your pack, because pen versions and local labels differ. Write the date you started a pen, or took it out of the fridge, on the label.
Travelling with GLP-1 pens
- Carry pens in hand luggage; aircraft holds can freeze them.
- Use an insulated travel case with a cool pack; don’t let the pen touch ice directly.
- Avoid hot cars, glove boxes, beaches and direct sun: temperatures can climb well above 30 °C within minutes.
- Bring a letter or prescription for security and customs, and keep pens in their original packaging.
- Time zones: weekly doses can usually be shifted by a day; check your leaflet’s rules on changing the injection day.
If a pen got too hot or froze
Semaglutide and tirzepatide are proteins (peptides). Heat breaks them down gradually; freezing can damage them immediately. If a pen has been frozen, or left above 30 °C for an extended period, or the solution looks cloudy, coloured or contains particles, don’t use it. Ask your pharmacist about a replacement; some manufacturers’ helplines can advise on specific temperature exposures. A damaged pen doesn’t usually cause harm; it just may not work.
Counterfeit pens have been found in several countries, including the US and Mexico. Buy only from a licensed pharmacy with a prescription. See buying diabetes medicines in Mexico.
Compounded and vial products
Compounded semaglutide or tirzepatide, sold by some clinics and telehealth services, comes with its own storage instructions and a beyond-use date set by the compounding pharmacy, often shorter than for branded pens. These products aren’t FDA-approved, and the FDA has warned about dosing errors and unapproved versions. Follow the label exactly, and be cautious with products sold “for research use only”. Missed-dose windows and other everyday rules are in the diabetes care guide.
Frequently asked questions
Does tirzepatide need to be refrigerated?
Yes, before use: keep Mounjaro and Zepbound pens in the fridge. If needed, single-dose pens can be kept unrefrigerated (below 30 °C) for up to 21 days.
My Ozempic pen was left out overnight before first use. Can I use it?
The leaflet only describes fridge storage before first use, so there is no official allowance. A pen kept at ordinary room temperature (below 30 °C) for a night is unlikely to be damaged, but ask your pharmacist or the Novo Nordisk helpline; a common approach is to start using it and count the 56 days from that point.
Should I put my in-use Ozempic pen back in the fridge?
You can, but you don’t need to. Either way, the 56-day limit after first use applies.
Sources and further reading
CanforaMedicine Guide
