Can you use Wegovy if it hasn't been refrigerated?

What the room-temperature rule actually means

The core question isn't whether a Wegovy pen ever left the fridge, it's whether it left the fridge for longer than Novo Nordisk's approved limit at a temperature within the acceptable range. The NHS semaglutide medicines page confirms that the pen should be refrigerated, and that there is a permitted window at room temperature. The precise figure lives in the Patient Information Leaflet that comes with every pen; the packaging may also state it. That figure matters because semaglutide can degrade when exposed to elevated temperatures for longer than the window allows, which would reduce its effectiveness without any visible change to the liquid.

Room temperature, for these purposes, typically means up to around 25°C, not a hot car in summer, not a windowsill in direct sun. If the pen was in a warm environment above that threshold, the permitted window shrinks further. The leaflet is specific; a general estimate from memory isn't a safe substitute for reading it, and if you're already weighing up whether you can still use a Wegovy pen that wasn't refrigerated, having the exact figures in front of you is the right starting point. Our page on how to store a Wegovy pen correctly walks through the full storage requirements if you want the broader picture before making your decision.

Frozen, warm, or room temperature, the differences matter

A pen that has been frozen is a different problem from one left at room temperature. Freezing can damage the delivery mechanism and potentially alter the medicine; the SmPC (Summary of Product Characteristics, available on the eMC) advises against using a pen that has been frozen. Inspect the liquid: it should be clear and colourless to slightly yellow, with no particles. If it looks cloudy, discoloured or contains visible particles, do not use it regardless of the temperature story.

Warmth beyond the permitted window is a subtler issue because the liquid may look exactly as it should. The medicine can still have degraded. Injecting a compromised pen isn't dangerous in the way a contaminated pen would be, but you may not get the full dose effect, and on a titration schedule, consistency matters. If you're uncertain whether your situation falls inside or outside the allowed window, our guide on what happens when Wegovy isn't refrigerated covers the degradation question in more detail.

One practical note: when your pen arrives through nume's service, it travels in temperature-controlled packaging via DPD, and the tracking notification lands on your phone before it does on your doorstep. That journey is managed. What happens once the pen is in your hands (in a bathroom cabinet that gets steamy, or a handbag left in a warm car) is where most storage questions come from.

The decision: use it, replace it, or ask first

You are essentially making a clinical judgement about a Prescription-Only Medicine. The structured way to approach it is: check the exact window stated in your leaflet; establish how long the pen was actually outside the fridge and at what temperature; compare the two. If the pen was outside the fridge for less time than the leaflet permits, at a temperature within the acceptable range, and the liquid looks normal, the pen is likely still within spec. If any of those conditions isn't met, treat it as compromised.

There is an important sub-question for people who have been following a titration plan: if replacing a pen means a gap before your next dose, discuss with your prescriber rather than improvising. Timing matters on a GLP-1 schedule. If you think your pen may have been left out but you're not sure for how long, the page on what to do if your Wegovy wasn't refrigerated sets out the practical steps clearly. For questions about the semaglutide molecule more broadly, our Wegovy information page covers how the medicine works and what to expect. Questions about the cost side of replacing a pen sit on our Wegovy cost context page, which explains what a legitimate private prescription includes.

If in doubt, the right person to call is your prescriber or pharmacist, not a forum. Reporting a concern about the quality of a medicine is also possible through the MHRA's Yellow Card scheme, which exists for exactly this kind of suspected product issue. Starting your care with a regulated service means you have a clinical team to ask: our prescribers are available seven days a week for aftercare questions.