Wegovy left unrefrigerated: can you still use it?

The storage rules as they actually work

Wegovy pens leave the factory refrigerated and are intended to stay that way until you use them. Cold storage (between 2°C and 8°C) is the default, and in that environment the pen is stable until its printed expiry date. The room-temperature allowance is a separate, finite buffer: the Wegovy SmPC published on the Electronic Medicines Compendium confirms the pen may be stored at or below 30°C for a permitted period, after which it must be thrown away. The exact number of days is stated in your Patient Information Leaflet. That figure is not approximate; it is the boundary the manufacturer's stability data supports, and treating it as a rough guide is where problems begin.

One detail that surprises people: the clock is cumulative. If you took the pen out for a few days in the summer, put it back in the fridge, then took it out again, the time away from refrigeration adds up. The pen does not reset every time it returns to the cold. So if your pen has had several outings, the total time out of the fridge is what you need to calculate, not just the most recent one.

Temperature matters too. The 30°C ceiling is not a loose ceiling. A pen left on a sunny windowsill, in a car in July, or near a radiator may have exceeded 30°C even if you were not tracking it. In those cases, the time limit becomes irrelevant; if you are unsure whether heat exposure has affected your pen, our page on whether you can use Wegovy if it has not been refrigerated walks through how to think about that question.

What actually happens to semaglutide when it warms up

There is a common assumption that an out-of-date or over-warm pen becomes dangerous. In most cases, that is not quite right. The real risk is that the active ingredient (semaglutide) degrades, meaning the dose you inject may be weaker than intended. You would not know this from looking at the pen. The liquid looks the same. That is part of why the guidance exists: there is no reliable visual check, so the time and temperature limits are the only signals available to you.

For context, a degraded pen is unlikely to cause acute harm, but it does mean your treatment is not working as it should. If you are trying to understand how Wegovy works and what it should be doing at your current dose, using a compromised pen quietly undermines that picture. You and your prescriber might conclude the dose needs increasing when the real issue was the pen.

The NHS patient information page for semaglutide confirms that Wegovy should be kept refrigerated and used within the permitted period once removed from the fridge, always check the leaflet inside your packaging for the specific figures, since they are the legally accurate reference for your product.

Making the decision: use it, bin it, or ask?

Here is the decision tree in plain terms. If the pen has been out of the fridge for less than the permitted number of days, has been kept below 30°C, and it is still within its expiry date: you can use it. If the pen has been out for longer than the leaflet allows, or the temperature is uncertain: bin it and use a new one. If you are not sure which applies: contact your prescriber or pharmacist before you inject. That third option is the one most people skip, usually because they feel awkward about a question that feels small. It is not small. A quick message is exactly what aftercare support is there for.

If you have been prescribed Wegovy through a private service and need to discuss your specific situation, that conversation belongs with whoever holds your prescription. At nume, our prescribers are available seven days a week for questions like this, it is part of what aftercare means. You can find out more about how we approach clinical support on our about us page.

One practical note: if you are regularly finding that your pen spends time out of the fridge because of travel or work, it is worth discussing this with your prescriber in advance. There are ways to plan around it. Separately, if you want to read more about timing your injection day to day, our page on when to inject Wegovy covers the flexibility you have there.

When a wasted pen means thinking about next steps

Discarding a pen that has gone out of condition is frustrating, especially given the cost of private weight-loss treatment. If this is a recurring issue, it is worth knowing that it comes up in broader conversations about weight-loss treatment options and how to make a chosen treatment sustainable day to day. The newer single-dose format of the higher-strength Wegovy pen has a slightly different form factor, and storage guidance can vary between pen generations, so always read the leaflet specific to the pen in your hand rather than relying on information for an older version.

If you have ended up here because a pen arrived warm from a delivery, that is a separate question about cold-chain handling during shipping rather than home storage, our detailed page on what happens when Wegovy is not refrigerated goes into that scenario specifically, and our page on receiving a Wegovy pen that was not refrigerated covers what to do if you are concerned about a delivery. For the general question of how semaglutide storage applies across formulations, our semaglutide storage guide broadens the picture.

If you are still working out whether Wegovy is the right route for you and would like a clinical assessment, you can check your eligibility through a free consultation with our prescribers.