The right temperature for Wegovy — and what happens if the cold chain breaks

Picture the scene: your pen has been sitting out since yesterday morning

You injected last week, left the pen on the bathroom shelf, and now you are not sure whether it is still safe to use. This is probably the most common storage worry our prescribers hear. The short answer is: check the time and temperature, then check the leaflet. Semaglutide is a protein-based molecule, and like most biologics it is sensitive to extremes. Refrigeration at 2–8°C is the standard home condition for all Wegovy injection pens before first use. The fridge keeps the medicine stable for the full shelf life printed on the carton.

Once you take a pen out of the fridge, the clock starts. Room temperature below 30°C is permitted for a defined period, the Patient Information Leaflet gives the exact number of days, and that leaflet is the authoritative source, not a forum post or a rough memory from your last prescription. The NHS semaglutide medicines page also summarises key storage points. If in doubt about a specific pen, contact the pharmacy that dispensed it rather than guessing. An unusable pen is frustrating, but injecting degraded medicine carries its own risks.

One thing worth setting straight gently: many people assume that as long as a pen looks normal (clear, colourless liquid) it must be fine. Unfortunately, protein degradation is not always visible to the eye. Appearance alone is not confirmation of potency. Store correctly from the start and you never have to make that judgment call.

What freezing does, and why the freezer drawer is the wrong place

Freezing is the storage error that causes the most irreversible damage. Semaglutide should never be frozen. If a pen accidentally touches the freezer compartment at the back of a fridge shelf, or is placed in a freezer by mistake, it must be discarded. The ice crystals that form during freezing disrupt the protein structure of the molecule, and there is no way to restore potency by thawing it out again. This applies whether the pen has been used once or is brand new.

The same principle applies to delivery. Wegovy pens are shipped in temperature-controlled packaging to protect the cold chain from our pharmacy to your door. At nume, pens are dispensed from a GPhC-registered pharmacy and dispatched with DPD's tracked next-working-day service in plain, unbranded packaging designed to keep contents at the correct temperature in transit. Once the parcel arrives, transfer the pens to your fridge promptly, do not leave them in a warm hallway or a car boot on a hot day.

If a delivery is delayed or a pen has been in an unrefrigerated parcel for longer than expected, the same rule applies: check the leaflet's guidance on room-temperature limits, and if you have any doubt, contact the pharmacy before using it. The nume support team is available seven days a week for exactly these questions.

Travelling with Wegovy: summer holidays, long journeys and airport security

Travelling does not have to mean a gap in treatment, but it does require a little forward planning. Most insulated cool bags or medical travel wallets will keep a pen within the 2–8°C range for several hours, which covers the majority of UK day trips and short-haul flights. For longer journeys or hot climates, a purpose-made medication cooler is worth considering.

At airport security, Wegovy pens are medical devices and are generally permitted in hand luggage. Carry your prescription or a pharmacist's letter confirming the medicine, especially for international travel, and it helps to know that there is a specific code used for Wegovy that can appear on paperwork and may be useful to have to hand when passing through customs or border checks. Checked baggage in aircraft holds can drop well below freezing, so always keep the pen with you in the cabin. If you are planning a trip, practical advice for travelling on Wegovy covers the specific steps that make the journey straightforward.

Heat is the other travel risk. A pen left in a hot car or a beach bag in direct sunlight can exceed 30°C within minutes on a warm UK day, let alone abroad. The 30°C limit is not generous headroom; it is the upper boundary for safe storage, not a target to approach. Keep the pen in the coolest part of your bag, out of direct light.

The Wegovy tablet: why storage is simpler for the oral form

Since the MHRA approved oral semaglutide (Wegovy tablets) on 11 June 2026, some patients have asked whether the storage rules are the same. They are not. The tablet formulation requires no refrigeration; it can be stored at room temperature, which makes it notably more convenient for travel and for anyone whose fridge situation is unpredictable. If cold-chain management feels like a barrier, this is one practical difference worth discussing with a prescriber during your consultation.

The oral form suits a different routine too: taken first thing in the morning on an empty stomach with a small amount of plain water, at least 30 minutes before food, drink or other medicines. Storage simplicity is one part of the picture, and if you are researching this medicine from scratch it is also worth knowing the different names Wegovy goes by, since semaglutide appears under more than one brand depending on the condition it is licensed to treat. If you have come across both Wegovy and Ozempic and want to understand how they differ, our Wegovy vs comparison page walks through the key distinctions, including licensing, doses, and how a prescriber weighs those factors before making a recommendation. Comparing Wegovy and Ozempic is a natural next step for anyone who has come across both names, as the two share the same active ingredient but are licensed for different purposes, at different doses, and a prescriber weighs all of that before recommending one over the other.

For context on how Wegovy fits within the broader landscape of licensed weight-management medicines, our weight-loss treatment overview sets out what is available and for whom. If you are ready to discuss which option suits your circumstances, a free consultation with a nume prescriber is the right next step, they review every application the same day and can answer storage and practical questions alongside the clinical ones. Eligibility is assessed on an individual basis, and our page on who qualifies for Wegovy by age is a useful starting point if you are unsure whether you meet the criteria before booking.