Wegovy can handle being out of the refrigerator for up to 28 days, as long as the temperature stays at or below 86°F (30°C). If it gets warmer than that, the medication starts to break down and should be thrown away. The good news is that brief exposure to room temperature, like leaving it on the counter overnight, is perfectly fine within those limits.
The Temperature Rules for Wegovy
Wegovy pens should be stored in the refrigerator between 36°F and 46°F (2°C to 8°C). That’s standard refrigerator temperature. But Novo Nordisk, the manufacturer, built in a generous window for real life: pens can be kept between 46°F and 86°F (8°C to 30°C) for up to 28 days, as long as the pen cap hasn’t been removed.
Two hard limits apply. First, the 86°F ceiling. Second, the 28-day clock. Once either is crossed, the pen should be discarded regardless of how it looks. And if a pen freezes at any point, it’s also done.
What Heat Does to the Medication
Wegovy’s active ingredient, semaglutide, is a peptide, a chain of amino acids folded into a specific shape. Heat causes that chain to degrade, producing impurities. Lab studies exposing semaglutide to elevated temperatures (40°C, 60°C, and 80°C) identified thirteen distinct breakdown products that formed as the molecule fell apart. The higher the temperature and the longer the exposure, the more degradation occurred.
This matters for two reasons. The degraded molecule loses its ability to work the way it should in your body, meaning reduced or zero effectiveness for appetite control and weight loss. Beyond that, the breakdown products themselves could potentially trigger immune reactions or other unwanted effects. This is why the manufacturer sets a firm temperature ceiling rather than suggesting the drug “might still be okay.”
How to Tell if a Pen Is Damaged
Before every injection, check the liquid inside the pen. It should be completely clear and colorless. If the semaglutide has started to degrade, the liquid will look cloudy, discolored, or you may see tiny particles floating in it. A pen that looks like this should not be used.
One important caveat: a pen can lose potency from heat exposure without any visible change. Clear liquid doesn’t guarantee the medication is still fully effective. If you know the pen was exposed to temperatures above 86°F, discard it even if it looks fine.
Common Scenarios and What to Do
If you left your Wegovy on the kitchen counter overnight in an air-conditioned home, it’s almost certainly fine. Normal room temperature falls well within the 46°F to 86°F window. Just put it back in the fridge and note the date. That pen now has a 28-day out-of-fridge countdown, minus however long it sat out.
If your pen sat in a hot car during summer, that’s a different story. Car interiors routinely reach 120°F to 150°F in direct sunlight. Even a short stretch in those conditions pushes the pen past the 86°F threshold, and it should be discarded.
If your pharmacy shipped Wegovy and it arrived warm to the touch after sitting on your porch, the same logic applies. If outdoor temperatures that day exceeded 86°F and the package wasn’t insulated, the safest move is to contact the pharmacy about a replacement rather than risk injecting a compromised dose.
If a pen accidentally freezes (pushed to the back of the fridge, placed too close to an ice pack), throw it away. Freezing damages the formulation even if the liquid looks normal after thawing.
Keeping Wegovy Cool While Traveling
Use a thermal or insulated case designed for injectable medications. These are widely available and many are specifically marketed for GLP-1 medications or insulin. The key detail: don’t place the pen directly against an ice pack, because that can freeze the medication. Wrap the ice pack in a cloth or use a case with a built-in barrier.
When flying, always keep Wegovy in your carry-on bag. Checked luggage sits in the cargo hold where temperatures can swing from well below freezing to extreme heat depending on the aircraft and route. Carry-on stays in the temperature-controlled cabin with you. For road trips, store the insulated case inside the passenger compartment rather than the trunk, which heats up significantly faster.
If you’re traveling for fewer than 28 days and can keep the pen under 86°F, you don’t necessarily need a refrigerator at your destination. But refrigerating it when you can will preserve the medication longer and give you more flexibility.
If You’ve Already Injected a Warm Pen
If you used a pen that may have been exposed to heat and are now worried, the most likely outcome is simply a less effective dose. The medication gradually loses potency as it degrades, so a pen that got mildly warm for a short time may have lost only a small fraction of its strength. A pen that baked in a car for hours is a bigger concern. Either way, there’s no need to panic. Contact your pharmacist or prescriber to discuss whether you need a replacement pen or an adjusted schedule for your next dose.