Keeping Wegovy in the fridge after opening: what the guidance actually says

Does the pen need to go straight back in the fridge after my injection?

Not immediately, but the fridge is where it should live between doses. Wegovy is a once-weekly injection, so there will be six days between each use. During that window the pen should be refrigerated at 2–8°C, away from the freezer compartment. The back of a fridge shelf, away from the door (where temperatures can fluctuate when the fridge opens and closes), tends to be more stable than the door rack.

If you find yourself wondering about all the practicalities of how to store Wegovy after opening, you are not alone. It is one of the questions our prescribers hear most regularly, and it is a sensible one to ask before you start rather than after.

One thing to do every time: check the liquid in the pen window before you inject. It should be clear and colourless. If it looks cloudy, discoloured or contains visible particles, do not use it and contact your pharmacist or prescriber. The NHS patient information for semaglutide covers what to look for, and it is worth reading before your first dose.

What if I need to carry the pen away from the fridge?

Life does not always allow for refrigeration, and Wegovy's manufacturer does allow a short period at room temperature. The precise number of days permitted, and the maximum temperature, are printed in the leaflet inside every pack. The detail matters because that figure is based on stability data for this specific formulation, it is not a rough estimate you can extend by keeping the pen in a cool bag.

A few practical points worth noting. Room temperature in the UK is usually fine in autumn and winter; a hot car in July is a different matter entirely. Never put the pen in direct sunlight, on a warm windowsill or near a radiator. If the pen has been left somewhere too warm and you are not sure whether it is still usable, your pharmacist can advise, that is exactly what they are there for.

For anyone travelling with Wegovy, the storage considerations after opening can involve airport security, hotel mini-fridges and time zone changes. Planning ahead makes it manageable.

Can a pen that has been frozen still be used?

No. Freezing damages the semaglutide molecule and makes the medicine unsafe to use. This is a firm rule, not a grey area. If your pen has accidentally frozen (perhaps it was in the fridge door near the ice box, or in a cool bag with ice packs) it should not be used. Check with your pharmacist about what to do next rather than trying to thaw and use it.

The same applies to a pen that has been left somewhere very cold, such as a car boot in freezing weather. Temperature damage is not always visible to the naked eye, which is precisely why the guidance exists.

It is also worth being aware of how Wegovy's expiry works after opening, because the clock on the room-temperature window starts the first time you remove the pen from the fridge, not from the date on the box. If you are unsure when that was, err on the side of caution.

When should I speak to someone about storage concerns?

If you have genuine doubt about whether a pen is still safe to use, talk to your pharmacist before injecting. It is always better to waste one pen than to inject something that has been compromised. Pharmacists can advise quickly, and in many cases the conversation takes two minutes.

If you are on treatment through a regulated online service and something has gone wrong in transit (for example, the delivery was delayed overnight and the pen arrived warm) contact the prescribing service directly. At nume, aftercare is available seven days a week for exactly this kind of question.

The NHS information on semaglutide is a reliable starting point for understanding storage and other practical aspects of Wegovy, and we would always encourage people to read it alongside their Patient Information Leaflet. If you are still deciding between injection and tablet formats, the question of whether Wegovy is injection-only has a clear answer, there is now an oral option too. And if you are earlier in your journey and still weighing up treatment routes, speaking to our prescribers is a good place to start. It is also worth knowing whether Wegovy needs to be kept in the fridge at all, and once you are clear on that, understanding how long you can keep Wegovy in the fridge will help you plan your storage routine with confidence.