How long can you store semaglutide, and when does it stop being safe to use?

Fridge versus room temperature: the core storage decision

The primary storage location for semaglutide pens is a fridge running between 2°C and 8°C. At that temperature, an unused pen remains stable until the expiry date printed on the label. That's straightforward enough when you're at home and your fridge is reliable.

The decision gets more complicated when you travel, lose power, or simply leave a pen on the bathroom shelf by mistake. Once a pen has been out of the fridge, a countdown begins. The exact number of days permitted at room temperature is stated in the Patient Information Leaflet for your specific pen format, different Wegovy pen strengths and the newer 7.2mg single-dose pen may carry slightly different instructions, so reading the leaflet for your pen is not optional. What is consistent across semaglutide products is that room temperature is typically defined as up to 30°C, and the window does not reset if you put the pen back in the fridge.

A practical checking habit worth building: before every injection day, look at the pen label and count how many days it has been out of the fridge. Takes under a minute, and it is the single most useful storage check you can do. If you are unsure how to read the label or track the date, our guide to storing semaglutide injections walks through it step by step.

What shortens a semaglutide pen's usable life

Temperature is the main variable, but it is not the only one. Three further factors can reduce how long a pen remains safe to use.

Freezing is the most decisive. A pen that has frozen (even for a short time, even if it looks unchanged when thawed) must be discarded. The medicine's structure is protein-based, and ice formation disrupts it in ways that are invisible to the naked eye. There is no way to test whether a frozen-then-thawed pen is still effective, so the answer is always to dispose of it safely.

Sunlight and heat exposure matter even when a pen has not technically exceeded its temperature limit. Leaving a pen on a windowsill in summer, or in a glove box during a warm day, can briefly spike its temperature well above 30°C. The same applies to leaving it near a radiator or in a bag left in a hot car. Consistent, low-level overexposure adds up, even if no single incident looks dramatic.

Physical damage to the pen body can also compromise the medicine. A dropped pen should be inspected before use: if the cartridge looks cloudy, discoloured or contains particles, do not inject it. Clear and colourless is the expected appearance for semaglutide solution, and our guide on how to mix a semaglutide injection covers what the solution should look like at each stage of preparation, alongside correct handling technique. You can find more detail on what to check visually, and how to handle the pen correctly, in our page on how to store semaglutide.

Refrigerator-specific rules that catch people out

Keeping a pen in the fridge sounds simple, but refrigerators vary. The 2–8°C requirement means the pen must not sit in the coldest zone, which in most household fridges is the back of the bottom shelf. If a pen accidentally contacts the back wall of a fridge that cycles below freezing at the coils, it can freeze without you noticing.

The fridge door is generally warmer and more stable in temperature than the interior shelves, practical for short-term storage, though you should still check the actual temperature with a fridge thermometer if you are unsure. The fridge-specific storage guide for semaglutide covers this in more depth, including what to do if your fridge malfunctions.

Pens should not be stored next to items that give off cold directly, such as ice packs. And the cap should be kept on between injections to protect the needle tip from contamination. The NHS medicines page for semaglutide confirms that storage conditions form part of the clinical guidance for this medicine and directs patients to the Patient Information Leaflet for their specific product.

Wegovy tablets and storage: a different set of rules

Since the MHRA approved the oral Wegovy tablet (semaglutide 25mg maintenance dose) in June 2026, not everyone using semaglutide for weight management is using an injection pen. The tablet form does not require refrigeration at all, room-temperature storage applies throughout, which makes it considerably simpler to manage during travel and daily routine.

That said, tablets still need to be stored away from heat and direct light, kept in their original packaging, and not exposed to moisture. The morning routine matters more with the tablet: it is taken on an empty stomach with a small amount of plain water, then at least 30 minutes pass before any food, drink or other oral medicines. Storage and administration are connected in that sense, disrupting either can affect how much medicine is absorbed. Our Wegovy treatment guide covers both the injection and tablet options if you are weighing up which format suits you.

For anyone comparing what different semaglutide products cost alongside how they are stored and used, the Wegovy price comparison page sets out the UK private-prescription landscape clearly.

If any storage situation leaves you uncertain (a power cut, a holiday, a pen that has been out longer than expected) the right step is to contact your prescriber before injecting. Our prescribers are available seven days a week for exactly these questions. When you are ready to talk through your treatment, speak to our prescribers through a free consultation.