What temperature should Wegovy be stored at — and what happens if it gets too warm?

Why the 2–8°C rule exists, and what crosses the line

Semaglutide is a biological medicine, a protein-based molecule that degrades when exposed to temperatures outside its licensed range. Refrigeration between 2°C and 8°C keeps the active ingredient stable from manufacture right up to the moment of injection. Two boundaries matter here, not just one. The upper limit (above 8°C for extended periods) accelerates degradation. The lower limit matters just as much: freezing physically damages the formulation in ways you cannot see by looking at the liquid.

That last point catches people out more than you might expect. Pens placed at the back of a fridge shelf, close to the cooling element, can freeze without the display ever showing a sub-zero temperature. It is worth checking where exactly yours sit. The NHS medicines page for semaglutide confirms that frozen pens should not be used, even if they have since thawed.

Light is a secondary but real factor. The pen's opaque casing offers some protection, but storing a Wegovy pen in direct sunlight on a windowsill (even for a short period) can push the temperature far above 30°C in a British summer. A fridge drawer or the door shelf (away from the seal) is the practical default for most people, and our guide on what temperature semaglutide needs to be stored at explains the reasoning behind each part of that recommendation.

The room-temperature window: what it is, why it exists, and how to use it safely

Most people do not inject Wegovy straight from the fridge. Cold liquid can increase discomfort at the injection site, so taking the pen out a short time beforehand is both practical and clinically fine, provided you stay within the room-temperature window specified in the leaflet. That window exists precisely for this: a defined, tested period during which stability is maintained below 30°C.

The exact number of days varies between product batches and can be updated when a new SmPC is issued, so the only reliable source is the Patient Information Leaflet in your specific box. If you have mislaid it, your pharmacist can provide a copy, or you can find the current version on the Electronic Medicines Compendium (eMC), which holds the authorised UK product information. Once the room-temperature period ends, the pen cannot go back into the fridge and restart the clock, unused medication should be disposed of responsibly, via a sharps container for the pen itself.

A useful mental rule: if you are not sure how long the pen has been out of the fridge, or you cannot account for part of that time, err on the side of caution and speak to your pharmacist before injecting.

Travel, holidays and situations where the fridge is not available

Travelling with a weekly injectable medicine requires a bit of forward planning, but it is genuinely manageable. If you want a thorough breakdown before you set off, our page on the temperature to store Wegovy covers the full range of conditions you may encounter, from airport security to hotel mini-bars. A few things to avoid: packing the pen in checked luggage on a flight (hold temperatures can drop well below freezing), leaving it in a car glove box in warm weather, or storing it next to ice packs without insulation, which risks accidental freezing. Insulated medication wallets designed for biological injectables can keep a pen within range for several hours in transit, they do not provide active cooling, so they are a bridge, not a substitute for a fridge on a long journey.

For detailed guidance specific to your treatment plan (including what to do if a pen is lost or damaged while travelling) our frequently asked questions page covers common scenarios, and our prescribers are available for aftercare queries seven days a week via the contact page.

When to be cautious, and what poor storage actually looks like

The semaglutide solution in a Wegovy pen should be clear and colourless to slightly yellow. Any cloudiness, visible particles, or a colour shift beyond pale yellow is a sign the medicine should not be used. This can result from freezing, overheating, or simply reaching the end of its stability window, and it is not always obvious from the outside of the pen that anything has happened.

If you are ever uncertain about whether a pen has been stored correctly (perhaps it arrived warm in a delivery you could not collect on time, or you found it in a bag from a previous trip) the right call is to contact your pharmacy before using it. That is not an overreaction; it is the sensible standard for any biological injectable. Our dedicated page on what temp Wegovy should be stored at walks through the specific scenarios where doubts most commonly arise and what to do in each case.

You can read a broader overview of how Wegovy behaves at room temperature and what the guidance says about shorter excursions from the fridge. For a fuller picture of the treatment itself, the Wegovy overview page covers how semaglutide works, who it is licensed for, and what private treatment typically costs in the UK. If you are still weighing up your options, our weight-loss treatment overview sets out the full landscape. Storage questions are one of the most practical things our prescribers can walk you through, start a free consultation to get personalised guidance from a GPhC-registered Independent Prescriber.