Wegovy can safely stay out of the refrigerator for up to 28 days, as long as the temperature stays between 46°F and 86°F (8°C to 30°C). Beyond that window, or above that temperature, the medication may lose effectiveness or become unsafe to use. Whether you accidentally left a pen on the counter overnight or you’re planning a trip, here’s what you need to know.
The 28-Day Room Temperature Window
Wegovy pens are meant to be stored in the refrigerator between 36°F and 46°F (2°C to 8°C). But Novo Nordisk, the manufacturer, builds in flexibility: you can keep a pen at room temperature for up to 28 days as long as it stays below 86°F (30°C) and remains in its original carton.
This means a pen left on a kitchen counter overnight, or carried in a bag for a few hours, is almost certainly fine. The 28-day clock starts when the pen first leaves refrigeration. After 28 days at room temperature, the pen should be discarded even if it looks normal.
One important detail: you can put a pen back in the fridge after it’s been at room temperature, as long as it was never exposed to temperatures above 86°F. Re-refrigerating doesn’t reset the 28-day clock, but it does help preserve the medication if you only needed it out temporarily.
What Heat Actually Does to the Medication
Wegovy’s active ingredient, semaglutide, is a peptide, a small protein-like molecule. Heat causes peptides to break apart and form degradation byproducts. Lab studies on semaglutide show that thermal stress generates multiple impurities, and even trace amounts of these breakdown products can reduce the drug’s effectiveness or potentially trigger immune reactions.
The damage isn’t always dramatic. A pen exposed to 90°F for a few hours won’t necessarily turn visibly different, but the molecule may have partially degraded in ways you can’t see. This is why temperature thresholds matter more than visual inspection alone.
When to Throw a Pen Away
Discard your Wegovy pen if any of the following apply:
- Temperature exceeded 86°F (30°C) at any point, even briefly. Think: left in a hot car, sitting in direct sunlight on a summer day, or stored near a heat source.
- It was frozen. Wegovy should never go in the freezer. Freezing can damage the protein structure just as heat does.
- It’s been out of the fridge for more than 28 days. Even if the temperature stayed within range the entire time.
- The liquid looks cloudy or contains particles. Normal Wegovy is clear and colorless when viewed through the pen window. Any cloudiness, discoloration, or floating particles means the medication is compromised.
If your pen meets any of these criteria, contact Novo Nordisk’s Patient Customer Care Center at 1-833-934-6891 to request a replacement. For disposal, don’t toss pens in the regular trash. Use a drug collection program or the Novo Nordisk Drug Disposal Program, and place pens in a proper sharps container.
How to Check If Your Pen Is Still Good
Before each injection, look through the pen window. The liquid should be completely clear and colorless. If it passes that visual check, and you’re confident it hasn’t exceeded 86°F or been out of the fridge for more than 28 days, the pen is safe to use.
That said, visual inspection has limits. A pen that sat at 95°F for several hours might still look clear but contain degradation products at the molecular level. When in doubt about temperature exposure, especially during summer months or power outages, it’s safer to discard the pen than to risk an injection that won’t work properly.
Keeping Wegovy Safe During Travel
Travel is the most common scenario where temperature control gets tricky. A few practical guidelines can prevent problems.
Always pack Wegovy in your carry-on luggage. Checked bags go into cargo holds where temperatures can swing to extremes. Use an insulated travel case or small cooler to maintain temperature, but don’t place the pen directly against an ice pack, as direct contact can freeze the medication. Keep the pen in its original carton to protect it from light.
Car travel requires extra caution. Glove compartments and trunks can reach well over 100°F in warm weather, far past the 86°F cutoff. Keep the pen in the passenger cabin, ideally in a cooler, and avoid leaving it in a parked car for any length of time. Even in mild weather, a closed car in the sun heats up fast.
For shorter outings, carrying the pen in a bag at room temperature for a few hours is perfectly fine and falls well within the 28-day, sub-86°F guidelines. The medication is more resilient than many people assume, as long as you stay within those two boundaries.