Almost certainly it is fine. Every GLP-1 is licensed to spend a stretch out of the fridge once the pen is in use, and even the shortest of those windows — Trulicity, at 14 days — is far longer than a night on the kitchen counter.
What matters is not last night. It is the running total since the pen first came out of the fridge, and the number of days you get is different for every one of these.
Every window, side by side
| Medication | Out of the fridge | The detail |
|---|---|---|
| Mounjaro | 30 days | Not above 30 °C once the pen is in use, then discard it even if there is medicine left. |
| Zepbound | 21 days | Up to 30 °C, and it cannot go back in the fridge afterwards. Discard at 21 days. |
| Wegovy | 42 days | Six weeks below 30 °C or in the fridge — the longest window of any of them. |
| Ozempic | 28 days | On the UK and EU leaflet. The US label says 56 days for the same pen — check the carton you were dispensed, not a search result. |
| Trulicity | 14 days | Not above 30 °C — the shortest window of the weekly injections, and half of Mounjaro's. |
| Saxenda | 30 days | One month below 30 °C or in the fridge once the pen is in use. |
| Victoza | 30 days | One month below 30 °C or in the fridge once the pen is in use. |
| Rybelsus | Not refrigerated | Tablets, not a pen. Room temperature in the original bottle or blister, away from moisture, and never the fridge. |
Read that table twice if you are on Trulicity. Fourteen days against Wegovy's forty-two is the difference between a pen that survives a holiday and one that does not, and both pens look exactly the same on day fifteen.
The clock does not reset
The window is cumulative time out of refrigeration, not consecutive time. Putting a pen back in the fridge for a few days does not buy back the days it already spent out, and there is nothing on the device that counts for you — which is the entire reason this is hard to get right over a month.
Zepbound goes further than the rest: its label says a pen that has left the fridge should not go back in at all. If you are on Zepbound, the day it comes out is the day the twenty-one starts, and there is no putting it on hold.
Two things that end a pen early
- Heat. Every window above assumes a temperature not above 30 °C. A pen left in a car in summer, in a bag in the sun, or on a windowsill is outside the terms of its licence no matter what the day count says.
- Freezing. A pen that has frozen must be discarded, even once it has thawed and even if it looks completely normal. This is the one that catches people out with a fridge set too cold, or a pen resting against the back wall of one.
Why the Ozempic answer changes depending on where you look
Because it genuinely differs by market. The UK and EU leaflet gives 28 days in use; the US label gives 56 days for the same pen. Neither is wrong, and a page that quotes one figure without saying which market it belongs to is the single most common error in this subject. Go by the carton you were actually dispensed.
An unopened pen is a different question
Everything above is a pen in use. An unopened pen is meant to stay refrigerated until you start it, and the in-use clock begins at the first injection — or, on most leaflets, whenever it left the fridge for good, whichever came first. Your own leaflet is the authority on which of those it means.
