Semaglutide storage temperature: what you need to know

The refrigerator rule, and why freezing is the one mistake that ends a pen

The standard storage requirement for semaglutide is refrigeration between 2°C and 8°C. That sounds simple, but the fridge itself creates one particular trap: the freezer shelf. Pens pushed to the back of a crowded refrigerator, or placed too close to the ice compartment, can freeze. Once frozen, the formulation changes in a way that cannot be reversed by thawing. The pen looks normal. The liquid may appear clear. But it should not be used.

The broader picture of semaglutide injection storage covers this in more detail, but the short version is: keep pens in the body of the fridge, not the door (temperature there fluctuates more than people expect), and not near the back wall. The original cardboard packaging serves a real function here, it insulates slightly and shields the pen from direct cold surfaces and light. Unopened pens stored this way, within their expiry date, are ready to use whenever you need them.

One misconception worth clearing up gently: some people assume that if the liquid looks clear and colourless, storage cannot have been a problem. Semaglutide is normally clear and colourless, but degradation from temperature exposure does not necessarily cloud it. Appearance is not a reliable check. The storage conditions themselves are what matter.

Room temperature: what the window means in practice

Once a Wegovy pen has been removed from the fridge (or if you lose refrigeration access for a period) the medicine can survive at room temperature for a limited time. The specific window, in days, is set by the manufacturer and confirmed in the Patient Information Leaflet. Because different pen formats and formulations carry different limits, and because the specifics of fridge storage for Wegovy are more nuanced than a single headline figure suggests, this page deliberately does not state the number: always check your own leaflet.

What the room-temperature window does allow for is practical daily life. Carrying a pen to a weekend away, keeping one out of the fridge on the morning of your injection, or travelling for a few days without a cool-bag, these are scenarios the window accommodates, within limits. What it does not accommodate is leaving a pen in a warm car in summer (the interior of a parked car can reach 50°C or more), storing one on a sunny windowsill, or simply forgetting to return it to the fridge for a week. If you are unsure whether a pen has stayed within safe conditions, the right answer is not to use it. Contact your prescriber or pharmacist first.

The NHS patient information page for semaglutide on NHS.UK confirms the core refrigeration requirement and directs patients to the leaflet for the room-temperature limit, a straightforward reference point if you have misplaced your packaging.

Travel, power cuts and other real-world decisions

Most storage questions are prompted by a concrete moment: a holiday, a flight, an unexpected power cut, a house move. These situations are worth thinking through before they happen rather than during them.

For travel, a cool-bag with an ice pack is the standard approach, but the pen should not touch the ice pack directly, because localised freezing is the same problem as freezer contact. Wrapping the pen in a cloth or keeping it in its box before placing it in a cool environment prevents this. If you are flying, keep the pen in your hand luggage rather than checked bags; hold temperatures are colder and less predictable. For longer trips, temperature management for Wegovy on longer journeys goes into this in more detail.

A power cut that lasts less than a few hours is unlikely to raise refrigerator temperature significantly if the door stays closed. Longer outages are worth monitoring with a fridge thermometer if you have one. If the fridge has warmed to room temperature, that time counts against the room-temperature window in your leaflet, it does not restart it.

If you are mid-titration and uncertain what to do with a pen that may have been outside safe conditions, speaking to your prescriber before your next injection is the right step. There is no clinical downside to asking. For questions about your specific situation, semaglutide storage conditions and what affects them covers the underlying factors in more depth, and our clinical team is reachable through the contact page seven days a week.

Disposal and what not to do with an unusable pen

If a pen has been compromised (frozen, overheated, or kept at room temperature beyond the permitted window) it needs to be disposed of safely, not simply put back in the fridge and reconsidered. Used or unusable pens and needles are classified as sharps and should not go in household bins or recycling. A sharps container is the correct disposal route; your local council or pharmacy can advise on collection. Replacing a pen that cannot be used safely is a practical matter rather than an unusual one, it happens, and your prescriber can help you navigate it.

If your treatment plan or pen format is changing and you have cost questions, a look at Wegovy pricing in the UK provides honest context on what private treatment involves. And if you are earlier in the process of exploring whether Wegovy is right for you, our guide to how to split Wegovy pens is worth reading before your first pen arrives, alongside the free consultation with our prescribers, which offers same-day clinical review, no waiting list, and a prescriber who can answer exactly these kinds of practical questions.