Do you need to keep Wegovy refrigerated — and what happens if you don't?

The myth: 'It must stay in the fridge at all times or it's ruined'

This is the version of Wegovy storage advice that causes the most unnecessary worry. The reality, set out in the Wegovy Summary of Product Characteristics published on the electronic Medicines Compendium (eMC), is that there are two distinct phases: storage before you open a pen, and storage once a pen is in use.

Before use, unopened pens need refrigeration at 2–8°C. Keep them in the body of the fridge rather than the door, where the temperature swings every time it opens. Do not store them next to the ice compartment or anywhere they could freeze. Freezing, even briefly, destroys the protein structure of semaglutide and makes the medicine unsafe to inject; a frozen pen cannot be rescued by thawing.

Once you begin using a pen, the rules change. The pen can then be kept at room temperature (specifically below 30°C) for a maximum of 28 days. After 28 days at room temperature it should be disposed of safely, regardless of whether it still contains doses. This window exists specifically to accommodate normal life: a long weekend away, a week's holiday, a period when access to a fridge is inconvenient. You do not have to carry a cold bag to work every Monday morning.

Worth noting: a question our prescribers hear most weeks is whether a pen left on the counter overnight is now unsafe. In most UK homes overnight room temperature sits well below 30°C, and a single lapse within the 28-day window is unlikely to compromise the medicine, but if you are ever uncertain, contacting your prescribing team is the right call rather than guessing.

Travelling with Wegovy, keeping the rules practical

Travel is where storage questions get real. On short trips, an in-use pen at room temperature under 30°C needs no special handling beyond keeping it out of direct sun and heat. For flights, the pen should go in your carry-on luggage, never in the hold where temperatures can drop well below freezing.

For longer trips where an in-use pen might exceed 28 days away from a fridge, or where you are carrying unopened pens, a medical cool wallet or small travel cooler keeps temperatures in range. The pen should never be placed directly against an ice pack, wrapping it protects against accidental freezing.

If you are travelling internationally and wondering about broader aspects of your weight-loss treatment, the Wegovy treatment overview on our site covers how the medicine works alongside the lifestyle changes that typically support it. Practical handling questions specific to your dose and circumstances are always best directed to your prescriber or our aftercare team, who are available seven days a week.

Checked pens should never go in the hold. Full stop. Airlines depressurise and chill cargo holds in ways that routinely freeze biological medicines. If security asks to scan the pen, that is fine; airport X-ray machines do not affect the medicine.

What compromised storage looks like, and what to do

You cannot always tell by looking whether a pen has been damaged. Semaglutide solution is normally clear and colourless to slightly yellow; if it looks cloudy, contains particles, or has changed colour, do not use it. Discard it in a sharps container and contact your prescriber for guidance on replacement.

If a pen has been frozen, the same applies: discard it, even if it looks normal on thawing. If a pen has been left somewhere unusually warm (a hot car in summer, a sunny windowsill) and you are not sure whether it exceeded 30°C or how long it was exposed, treat it as suspect rather than risk injecting compromised medicine.

The NHS semaglutide medicines page provides patient-level guidance on storage alongside other practical information about the medicine. For side effects specifically related to the injection, including injection-site bleeding, separate guidance applies and a prescriber or pharmacist should be consulted if anything concerns you.

Any suspected quality issue with a medicine (including a pen you believe was stored incorrectly before you received it) can also be reported through the MHRA's Yellow Card scheme, which is open to patients and healthcare professionals alike.

Storing Wegovy alongside the rest of life, a few practical notes

Most people find it simplest to keep unopened pens at the back of a dedicated fridge shelf, away from food that gets moved around. Labelling the shelf or the carton with the date you started an in-use pen means you never have to guess whether the 28-day room-temperature window has expired.

If cost is part of how you are thinking about treatment, it is worth knowing what is included in a private prescription: the Wegovy cost page explains the components that make up a private prescription price and what to look for when comparing providers. For broader context on the range of weight-loss treatment options available in the UK, including how injection-based medicines differ from the newer oral formats, that page sets it all out clearly.

If you are weighing Wegovy against other injection-based options, the semaglutide family is not the only GLP-1 medicine licensed for weight management in the UK. Understanding the differences is a genuine clinical conversation rather than a checklist exercise, and it is precisely the kind of question a prescriber reviews individually at consultation. When you are ready to have that conversation, starting a free consultation with our team is the straightforward next step.