Wegovy out of the refrigerator: how long is safe, and what to do when things go wrong

Why the refrigerator matters, and what actually happens to semaglutide at room temperature

Semaglutide is a peptide medicine. Like most biologics, it is sensitive to heat: sustained warmth degrades the active molecule, reducing both potency and predictability of effect. The pen itself (a pre-filled, multi-dose device) contains a fixed quantity of medicine for four weekly injections, so a single compromised pen represents a whole month of treatment.

What the Novo Nordisk SmPC (the prescribing document you can read on the eMC) establishes is that Wegovy pens tolerate a defined window outside the fridge. That window is calibrated so that the kind of short, unavoidable interruption that happens in real life (a delivery left on a doorstep for an hour, a pen left on the kitchen counter while you take a call) does not automatically mean a wasted pen. But the limit is a limit, not a suggestion. Once it is passed, the guidance is clear: discard, not use.

Temperature matters as much as time. A pen sitting at 18°C on a cool day behaves differently from one baking in a car glove box at 30°C. The permitted room-temperature window applies at up to 25°C. If the ambient temperature has been higher than that (a hot car, a sunny windowsill) the effective safe period is shorter, and when in doubt, discarding is the right call. Your Wegovy treatment overview has further context on how the medicine works and what to expect during treatment.

The decision tree: what to do when you find a pen that has been left out

When you discover an unrefrigerated pen, the first step is to estimate (honestly) how long it has been out and at roughly what temperature. Write it down if that helps.

If the pen has been out for less than the maximum permitted period and the room has stayed below 25°C, return it to the fridge and use it within the remaining time allowed by your leaflet. Do not clock-reset: the total time out of the fridge is cumulative across all occasions, not per episode.

If the pen has been out longer, or if you genuinely cannot tell, discard it. Use a sharps container for safe disposal, Wegovy pens are medical sharps and must not go into household recycling or general bins. Contact your prescriber to discuss your next steps, which may include an early repeat prescription. For any question about whether your specific pen is still suitable, our team is available seven days a week.

Never freeze the pen to buy more time. Freezing destroys the formulation. A pen that has turned to ice (even briefly) is not recoverable by thawing.

Travel, deliveries and the moments most people lose track of time

The scenarios our prescribers hear about most often are not dramatic. A delivery arrives in the morning and sits in a hallway for three hours before anyone notices. A pen is packed into hand luggage and spends two hours going through airport security in a warm terminal. A week away from home means the pen lives in a hotel minibar, and the minibar turns out to be colder than 2°C.

That last point is worth pausing on: a Wegovy pen that has been frozen is just as compromised as one that has overheated. Minibars and drinks fridges can run colder than a domestic fridge shelf; check the temperature setting before storing your pen in one.

For longer trips, a small insulated cool bag with an ice pack (not in direct contact with the pen) is the practical solution. The pen itself, once out of the fridge for injection, should be at room temperature for a few minutes, injecting cold medicine can be uncomfortable. That brief warm-up period counts toward the cumulative out-of-fridge time; it does not restart the clock.

If you are comparing how Wegovy's storage requirements stack up against other semaglutide products, this page on semaglutide refrigerator life covers the broader picture, including what the data says about degradation over time. For those on treatment through nume, the pen arrives via DPD in a purpose-designed cold-chain pack (tracked to your phone, in plain packaging) so the storage clock starts from the moment it reaches your hands in good condition.

When a lost or damaged pen affects your treatment schedule

Missing a weekly injection because a pen had to be discarded is not a clinical emergency, but it is something to handle promptly. The NHS guidance on semaglutide advises that if you miss a dose, you should take it as soon as possible if it is within five days of the missed injection. If more than five days have passed, skip that dose and continue with your next scheduled one. Do not double-dose.

If a ruined pen means you will miss more than one injection, contact your prescriber. In some circumstances a bridging discussion is needed, particularly if you are on a higher maintenance dose where a longer gap might prompt GI symptoms on restarting. If you want to understand exactly how long a Wegovy pen can stay in the refrigerator before it is no longer viable, that detail can help you plan ahead, and keeping a record of when each pen was opened and how much time it has spent outside the fridge takes no more than a note on your phone.

For context on what Wegovy treatment costs and what a repeat prescription involves through a private provider, this cost comparison page sets out the realistic figures. Starting treatment properly (with a full clinical review, genuine supply chain and reliable aftercare) is the foundation that makes storage questions like this one answerable rather than stressful. If you are not yet on treatment, start your free consultation with our prescribers to see whether Wegovy is suitable for you.