I Left My Wegovy Out of the Fridge — Here's What Actually Matters

The biggest myth: 'Out of the fridge means it's ruined'

This is the worry that lands in prescribers' inboxes regularly, and it's understandable. Wegovy comes refrigerated, so it's easy to assume it must stay refrigerated every minute you own it. The reality is more forgiving. The Wegovy SmPC (the full prescribing information held on the electronic Medicines Compendium) confirms that Wegovy pens can be stored at room temperature, at or below 30°C, for a cumulative total of up to 28 days. That window applies whether the pen is sealed or already in use.

So finding your pen on the kitchen counter in the morning, or realising it's been in your bag for a week, doesn't mean you've wasted it. The 28-day clock is cumulative: if a pen spent four days out of the fridge in January and three days out last week, those count together toward the 28-day total. Most people find it easier to keep a note on their phone or a sticky label on the pen cap with the date it first came out of the fridge.

What does make a pen unusable: temperatures above 30°C, direct sunlight (the medicine is light-sensitive), and freezing. A pen left on a sunny windowsill in July or stored in a car glove compartment in summer may not be safe even if it's only been hours. For a genuinely detailed look at the full storage guidance, the storage guide for Wegovy pens covers the rules in more depth.

What to check when a pen has been left out

Before using a pen that's spent time outside the fridge, run through three quick checks. First, temperature: could the room, bag, or surface it sat on have exceeded 30°C? On a warm UK summer day a car interior can reach 60°C, and even a south-facing windowsill climbs quickly. Second, time: how long has it actually been out? If you're not certain, treat the estimate conservatively. Third, appearance: check that the liquid in the pen window looks clear and colourless, not cloudy, discoloured, or containing visible particles. If anything looks off, don't use it.

Holidays are a common flashpoint here. A Wegovy pen packed in hold luggage (sometimes exposed to temperature extremes in the cargo hold) or left at the bottom of a suitcase in a hot hotel room can accumulate risk quickly. Planning ahead with a small cool bag (not a freezer block directly against the pen) helps on longer trips.

If the pen has been out for fewer than 28 cumulative days, temperatures stayed below 30°C, and it looks normal, the guidance supports using it. If you're still unsure, contact your prescriber or pharmacist before injecting. For a specific scenario, our guide on whether Wegovy is ok out of the fridge walks through the key questions to ask yourself. For a pen left out overnight, the overnight storage question is answered separately.

The one scenario where you should not use the pen: freezing

Freezing is a hard line. If your Wegovy pen has been frozen at any point (perhaps stored too close to the back of the fridge where the temperature drops below zero, or accidentally placed in a freezer) discard it. Freezing degrades semaglutide in ways that aren't visible to the eye. The liquid may look completely normal after thawing, but the medicine inside may no longer work properly. This is not a recoverable situation in the way that a brief period at room temperature is.

The NHS tirzepatide and semaglutide storage guidance both flag this point clearly: the NHS semaglutide page notes that pens that have been frozen should be thrown away. Keep pens in the body of the fridge rather than the door or the rear wall, where temperatures are more stable. If you're wondering about medicine remaining in a used pen, our page on Wegovy left in the pen explains how to handle partially used pens and store them correctly.

It's also worth noting that semaglutide storage rules apply equally to the GLP-1 class more broadly. If you're researching storage for a different injectable medicine in this group, the semaglutide storage page brings together the rules across formulations.

What to do if you've already injected from a pen you're worried about

First: don't panic. If you injected from a pen that had been out of the fridge within the 28-day window, at temperatures below 30°C, you almost certainly haven't come to any harm. The medicine may have been slightly less potent in a borderline storage situation, but there's no acute safety risk from a degraded pen in that sense.

If you're genuinely concerned that the pen was compromised (because of high-temperature exposure or a long unknown period out of the fridge) the right step is to contact your prescriber. They can advise whether to count that dose as taken, repeat the injection, or wait until the next scheduled dose. Never take an extra dose on your own initiative: the timing and titration of semaglutide is something your prescriber manages, not something to adjust without guidance.

Wegovy is a prescription medicine. Every prescription issued through a regulated service like ours comes with access to prescribers who can answer exactly these questions. If you have questions about your treatment going forward, you can also check your eligibility or reach our clinical team directly. And if you'd like to understand more about how Wegovy works as a treatment, the Wegovy overview page is a good starting point.