How long can you keep Wegovy out of the fridge?

What the Wegovy SmPC actually says about out-of-fridge storage

A question our prescribers hear most weeks is whether a Wegovy pen that has been left out overnight is still safe to inject. The honest answer is: it depends on exactly how long it was out and the temperature it was kept at, and only the SmPC gives you the definitive number to compare against.

The licensed storage instructions for Wegovy are set by Novo Nordisk and approved by the MHRA. They specify that the pen may be stored outside the fridge at room temperature, below a defined upper temperature threshold, for a limited number of days. That window exists to accommodate real life (travel, a power cut, forgetting to refrigerate after unpacking) but it is not generous, and it is not flexible. Once the pen has spent its allowance of time at room temperature, it cannot be "reset" by putting it back in the fridge.

We are deliberately not repeating the exact number of days here, because two different pen formats and ongoing licence updates mean the correct figure for your pen may differ from anything you have read online. The Wegovy SmPC on the eMC is free to access, takes two minutes to read, and carries the current approved figure. Your Patient Information Leaflet, tucked inside the box, is the same authoritative source.

One practical point the SmPC does make clear: the pen should be protected from light and kept away from heat sources throughout the out-of-fridge period, not simply placed on a sunny windowsill or in a warm car.

The three things to weigh up before you inject

Think of this as a short checklist rather than a guessing game. Before using a pen that has been outside the fridge, consider three things.

First, total time out. Add up the periods honestly. If you took the pen out on Monday for a day trip, returned it to the fridge, then took it out again on Wednesday, both periods count toward the cumulative total. The SmPC limit applies to the sum, not to any single stretch.

Second, temperature. Room temperature in a cool UK kitchen in January is very different from a hot car in August or a bag left in direct sun. If the pen was exposed to temperatures above the SmPC's upper storage limit at any point, the manufacturer's guidance is to discard it regardless of how little time has passed. Semaglutide is a protein-based medicine; heat degrades it in ways that are invisible to the eye. The liquid may still look clear and colourless, but efficacy and safety cannot be confirmed once the cold chain has been significantly breached. Our page on whether you can keep Wegovy out of the fridge explains the temperature boundaries and what counts as a breach in more detail.

Third, whether the pen has been used. A pen you have already started follows the same rules, but some people are surprised to learn that the out-of-fridge window starts from when the pen is first removed, not from when it is first injected. If you are uncertain about any of these three factors, our Wegovy treatment overview explains what is included in ongoing clinical support, and a quick message to your prescriber is the right next step.

For broader context on how semaglutide compares with other licensed weight-loss options, the weight-loss treatments overview covers the current landscape.

When to discard the pen and what to do next

There are situations where the decision is straightforward: discard the pen. If it has been out of the fridge beyond the SmPC's stated limit, discard it. If it was exposed to a high temperature, discard it. If the solution appears cloudy, discoloured or contains particles, discard it without injecting. A pen you have doubts about is not worth the risk of using an ineffective or degraded dose.

Disposal matters too. Used or degraded pens should not go in the household bin. A sharps container is the correct way to dispose of pens safely; your local pharmacy or GP surgery can advise on collection points.

If you have discarded a pen and need a replacement sooner than your next scheduled order, contact your prescriber before simply ordering again, particularly if a dose increase is due. The NHS semaglutide medicines page also covers storage and missed-dose guidance in plain language and is worth bookmarking alongside your Patient Information Leaflet.

For anyone travelling with Wegovy, the core principle is the same: keep the pen cold, track the time it spends out of refrigeration, and stay within the SmPC limit. Planning ahead makes this straightforward, and if you are based locally you may also find it useful to review our Wegovy injections service in Walsall for information on in-person clinical support. Our page on how long Wegovy can be out of the fridge covers travel scenarios in more detail, and how long semaglutide can stay outside the fridge addresses the same question for anyone thinking about the active ingredient across different branded products.

If you have questions about your current treatment or storage concerns have led you to miss a dose, speaking to a prescriber is the right move. If you want a clear, specific answer on how long you can keep Wegovy in the fridge before it needs to be used, that page sets out the manufacturer's guidance in full. At nume, every repeat order goes through a same-day clinical review by a GPhC-registered prescriber, so storage questions are always part of a broader, joined-up conversation. Speak to our prescribers whenever you need clarity.