How Long Does Wegovy Last in the Fridge?

How long does Wegovy last in the fridge once you have opened a pen?

The 56-day figure applies from the moment you remove the cap and use the pen for the first time. Before that point, an unopened pen is simply stored in the fridge at 2–8°C until its printed expiry date, which could be many months away. Once you start a pen, the 56-day clock begins regardless of how many doses remain in it. The NHS medicines information page for semaglutide is a useful first stop for checking this, and the full technical detail lives in the Wegovy SmPC on the Electronic Medicines Compendium (eMC).

Practically, 56 days is eight weeks. Most people on the standard four-weekly titration schedule use one pen every 28 days, so if you are wondering how long one pen of Wegovy lasts on a typical schedule, it is usually finished well within that window. Where people run into trouble is if a dose is delayed, or if they lose track of when they first opened a particular pen. Writing the opening date on the label with a marker is a small habit that removes all the guesswork.

If you want a deeper look at what affects how long a single pen lasts dose-by-dose, the guide on how long a Wegovy pen lasts covers that in more detail.

What fridge conditions does Wegovy actually need?

The target range is 2–8°C, which is the standard medicine-fridge zone and roughly what the salad drawer of a domestic fridge sits at. That said, not all parts of a fridge are equal. The door shelf (where many people instinctively put injections) tends to fluctuate most because it is opened frequently. The middle or back of a dedicated fridge shelf is more stable.

Two temperatures to avoid: freezing and excessive heat. Wegovy must never be frozen. If a pen is accidentally placed in the freezer, or sits against the freezer compartment wall of a combined fridge-freezer and partially ices, it should be discarded. The formulation is damaged by ice crystal formation in a way that is invisible to the eye, the liquid will look normal. There is no rescue step; a frozen pen is a wasted pen.

For periods outside the fridge, Wegovy can tolerate room temperature below 30°C for a limited time. The exact out-of-fridge window is specified in the Patient Information Leaflet; the page on how long Wegovy can stay out of the fridge walks through those specific limits and what to do if the window is exceeded.

One everyday note: keeping the pen in the fridge door next to the butter is convenient but not ideal. A dedicated spot on an interior shelf, away from the back wall, is the more consistent option.

What happens to a pen that has been stored incorrectly?

Semaglutide is a protein-based medicine. Proteins degrade when exposed to temperatures outside their approved range, and that degradation does not produce visible changes in most cases. The liquid will not turn cloudy or change colour in the way that some older medicines do when they spoil. This is precisely why the storage rules exist: you cannot tell by looking.

If you suspect a pen has been frozen, left in a hot car, or left at room temperature for longer than the leaflet allows, the guidance from the NHS semaglutide medicines page is consistent with the SmPC: when in doubt, do not use the pen. Contact your prescriber or pharmacist for advice rather than injecting with a pen of uncertain provenance. At nume, our prescribers are available seven days a week for exactly this kind of aftercare question, you can reach us through the contact page.

Disposal matters too. A pen that can no longer be used should be placed in an approved sharps container rather than in household waste, even if the needle has not been attached. The pen body itself is considered clinical waste once it has been used.

Does all of this apply to semaglutide in general, or just to Wegovy specifically?

Semaglutide is the active ingredient in both Wegovy and Ozempic, and both are injectable semaglutide products. The storage chemistry is the same, so the 2–8°C fridge requirement and the 56-day post-first-use rule apply to injectable semaglutide broadly. How long semaglutide lasts in the fridge, in that sense, is the same answer for either pen.

The important distinction is licensing. Ozempic is licensed in the UK for type 2 diabetes, not for weight management. If you are using semaglutide for weight loss, the relevant product is Wegovy, and the storage information in Wegovy's own leaflet is the version to follow, since the pen formats differ. The Wegovy treatment page explains the licensing position and how the prescription process works in more detail.

Wegovy 7.2mg, the higher-dose pen approved by the MHRA in April 2026, follows the same refrigerated-storage principle; always check that pen's specific Patient Information Leaflet for its confirmed figures. For context on how Wegovy compares with other weight-loss treatment options, the treatment overview covers the landscape. If you are also curious about how the medicine works at a physiological level, the semaglutide mechanism of action page explains the GLP-1 receptor pathway in plain terms.

Storage questions often come up at the same time as practical questions about cost and continuity of supply. An overview of Wegovy pricing in the UK may be useful if you are planning ahead financially. Treatment with Wegovy is a prescription-only process; speaking to our prescribers is the right starting point if you have not yet had a clinical assessment or if your storage situation has raised a question about whether to continue your current pen.