Wegovy storage temperature: keeping your pen safe between doses

The pen is waiting in the fridge, and then life happens

Picture this: you collected your Wegovy pen on a Friday, slid it into the fridge door, and then the weekend filled up. By Sunday evening you realise it has been sitting next to something frozen and the fridge temperature may have dipped too low overnight. This is one of the most common storage questions our clinical team fields, and it is worth knowing the rules clearly before you are in that situation rather than after.

The manufacturer's guidance, set out in the Wegovy Patient Information Leaflet and the Mounjaro and Wegovy SmPCs held on the eMC, is consistent: store the pen in a refrigerator between 2°C and 8°C. That range is tighter than a typical fridge runs by default, so it is worth using a fridge thermometer if you have any doubt about your appliance. Keep the pen in its original carton to protect it from light, and position it away from the freezer compartment and the back wall of the fridge, where temperatures can fall below zero. Freezing destroys the medicine. A frozen pen should not be used.

If you are unsure about what temperature Wegovy should be stored at and why that range matters, the short answer is: cold, not freezing, and away from direct light. The NHS medicines guidance for semaglutide aligns with this, and the SmPC is the definitive reference for exact figures and storage durations.

Room temperature: the window, and when it closes

There is a permitted period during which a Wegovy pen can be kept at room temperature (broadly, up to 25°C) once it has been removed from the fridge. The Patient Information Leaflet states the exact number of days; this page does not reproduce that figure because the SmPC takes precedence and the number should be read directly from your pen's packaging or leaflet rather than from any secondary source. What matters practically is that once you reach the end of that window, the pen should not go back into the fridge and be treated as if the clock has reset. Once the room-temperature period is up, the pen must be discarded.

For most people this window is more than enough for a single weekly injection. Where it becomes relevant is during travel, holidays or the kind of week where the injection keeps getting postponed. If you are planning a break away (especially somewhere warm) check the detail on Wegovy at room temperature before you pack. Insulated travel pouches designed for insulin pens are widely available and work well for semaglutide pens too, provided they keep the pen below 25°C and above freezing.

One thing worth timing: if your prescription is due to arrive around a bank holiday or payday weekend, make sure someone is home to receive it. DPD delivers tracked and next-working-day, but a pen sitting in a warm hallway or left outside is no longer in controlled storage. Plan the delivery date around your diary.

What happens if the pen gets too warm or is accidentally frozen

Both extremes damage semaglutide. Heat accelerates degradation of the protein structure of the medicine; freezing causes ice crystal formation that can alter the formulation. Neither process is visible to the naked eye, which is exactly why the rule is simple: if you are not certain the pen stayed within the permitted temperature range, do not use it.

A pen left in a hot car, kept near a radiator, or accidentally frozen overnight in the fridge should be treated as compromised. Dispose of it correctly (a sharps container is the right way to dispose of pens and needles safely) and contact your prescriber or pharmacist. Do not attempt to warm a frozen pen in hot water or use a pen that has visible particles or discolouration. The NHS semaglutide guidance advises checking the solution before every injection: it should be clear, colourless and free of particles.

If in any doubt about whether a pen has been compromised, our team is reachable seven days a week. Getting this right matters: an ineffective pen means a missed dose, not just a wasted one. You can read more about how Wegovy storage conditions affect the medicine if you want the background in more depth.

Travelling, changing routines and keeping storage consistent

Semaglutide temperature storage becomes most complicated when routine breaks down: a holiday, a business trip, moving house, or simply a week when the fridge is unusually full and the temperature climbs. A few practical habits help.

Keep the pen in its original carton rather than loose in the fridge shelf. If you travel by air, carry the pen in your hand luggage, aircraft hold temperatures are not controlled and can fall well below freezing. A letter from your prescriber confirming the prescription is useful at airport security. On arrival, prioritise finding a fridge before unpacking anything else, and if you want a full refresher on the right temperature to store Wegovy during trips and at home, that page sets it out clearly.

At home, a dedicated drawer or shelf in the fridge door (not the coldest zone) keeps the pen consistently within range without requiring active management. If you are curious about the detail of what temperature semaglutide specifically needs across different situations, that page covers the practical variations in more depth.

Wegovy is a clinically significant medicine, dispensed only on prescription, and correct storage is part of using it safely. If you are exploring weight-loss treatment options, including how Ozempic and similar injections compare, or want advice from our clinical team, you can speak to our prescribers at any point via a free consultation.