How Long Can Wegovy Stay Out of the Refrigerator?

Step 1, Know the room-temperature limit before you open the box

The standard room-temperature allowance for Wegovy injection pens is up to 28 days at or below 30°C. That figure comes from the NHS semaglutide medicines page, which consolidates the manufacturer's SmPC guidance for patients. Twenty-eight days is a cumulative total, not a daily reset, so if a pen spent a fortnight at room temperature last month and you then returned it to the fridge, you have roughly two weeks of room-temperature time left, not a fresh 28 days.

Keep the pen away from direct sunlight and away from heat sources such as radiators, windowsills and car dashboards. If the ambient temperature in your home regularly creeps above 25°C in summer, a cool bag or insulated case during the day is worth considering. The fridge should sit between 2°C and 8°C; anything colder risks freezing the medicine.

One thing worth clearing up gently: a lot of people assume that because injectable medicines need refrigeration, any time spent outside the fridge is automatically harmful. That is not quite right. Manufacturers account for practical real-world use (clinic visits, travelling to a GP appointment, a morning spent on the kitchen counter) when they set the room-temperature limit, and our page on Wegovy out of the refrigerator explains exactly what happens during that window and what to watch for. The 28-day figure is a tested tolerance, not a rough guess.

The safest habit is to note the date the first time the pen leaves the fridge for a sustained period, and track it from there.

Step 2, Spotting a pen that may have been compromised

Before every injection, take a moment to inspect the solution. Wegovy should appear clear and colourless; if it looks cloudy, discoloured, or contains particles, do not inject it. The same applies if the pen has been frozen: ice crystal formation can alter the medicine's structure even after it thaws. A pen that has been frozen (left in a bag in a cold car overnight in January, for instance) should be set aside and your prescriber or pharmacist contacted before you proceed.

Heat damage is harder to see. A pen that has sat in a hot car (where temperatures can reach 50°C or above in summer) may look normal but still be degraded. When in doubt, treat the pen as compromised and ask for guidance. The instinct to use it rather than waste it is understandable, but injecting degraded semaglutide carries real risk of reduced efficacy or unexpected reactions.

You can find detailed guidance on spotting and reporting suspected problems through the MHRA Yellow Card scheme, which also covers reporting any adverse reactions you experience during treatment.

If you have questions about a specific pen that has been stored incorrectly, our team is available seven days a week, get in touch and a prescriber can advise.

Step 3, Travelling with Wegovy and longer-term planning

Travel is where storage goes wrong most often. A weekend away, a long-haul flight, a hot airport terminal, each creates a window where temperature control slips. An insulated medication travel case with a gel ice pack (not in direct contact with the pen; freezing it is as bad as overheating it) is the practical answer for most journeys. Airline security rules in the UK allow injectable prescription medicines in hand luggage; carrying your prescription or a letter from your pharmacy helps at security if asked.

For longer trips, plan your supply carefully. If a pen will travel at room temperature for more than a day or two, factor that into your 28-day allowance before you set off, and if you want a clear breakdown of how refrigerated storage works across the pen's full shelf life, our guide on how long Wegovy can stay in the refrigerator gives you the detail you need before you leave. Pens that are still within their allowance on return can go straight back into the fridge. Those that have exceeded it should be disposed of safely, a sharps container is the correct way to discard used or compromised pens, keeping others in your household safe.

For a broader look at how long you can keep semaglutide refrigerated across its shelf life, our page on keeping semaglutide in the refrigerator covers the unopened-pen timeframes in detail. And if you are comparing storage considerations across pen formats, our guide to the Wegovy multi-use pen is a useful companion read.

When your storage question becomes a clinical question

Most storage queries can be answered by the leaflet in your box or by a quick call to a pharmacist. Some cannot. If you are unsure whether a dose you have already taken came from a compromised pen, if you are experiencing unexpected side effects that might relate to altered medicine, or if you have been managing a complex storage situation over several weeks, those questions deserve a prescriber's eyes rather than a search engine.

The cost of a Wegovy prescription is a consideration for many people, and losing a pen to incorrect storage stings financially as well as practically. Our Wegovy cost page sets out what a private prescription typically involves in the UK, so you can plan ahead. Understanding the full picture on Wegovy (how it works, what the treatment journey looks like, and how clinical review fits in) also helps you get the most from each pen.

At nume, our prescribers review every patient's situation individually. If you have specific concerns about a pen or your storage arrangements, speaking to our clinical team is the right next step. You can also browse our frequently asked questions for quick answers on common storage and treatment queries.