If a Wegovy pen has frozen, you should throw it away and not use it. Novo Nordisk is clear on this point: a pen exposed to freezing temperatures is considered compromised, even if the liquid has thawed and looks normal again. The medication may no longer work as intended, and there is no way to reverse the damage at home.
Why Freezing Ruins the Medication
Semaglutide, the active ingredient in Wegovy, is a peptide, a type of small protein. Proteins hold their shape through delicate bonds with the surrounding water molecules in the solution. When that solution freezes, those bonds break. Ice crystals can physically disrupt the protein’s structure, a process scientists call denaturation. Once a protein unfolds or changes shape, it can lose its ability to interact with the receptors in your body that control appetite and blood sugar.
Freezing also concentrates the other ingredients in the solution, which can trigger chemical changes like oxidation of specific building blocks within the peptide. These changes happen at the molecular level, so a pen that froze and thawed can look perfectly fine while containing medication that is partially or fully inactive. You would have no reliable way to know how much potency remains.
How to Tell if Your Pen May Have Frozen
Sometimes it’s obvious: you left a pen in a car overnight in winter, or your pharmacy shipped it during a cold snap and the pack arrived ice-cold. Other times it’s less clear. Your refrigerator might have a cold spot near the back wall or close to the freezer vent that dips below 32°F (0°C) without you realizing it.
Before each injection, check the liquid through the pen’s viewing window. Wegovy should look clear and colorless. If you see cloudiness, floating particles, or any discoloration, do not use the pen. Keep in mind that condensation on the outside of the glass tube is normal when a cold pen hits room-temperature air. Wipe the pen down and look again. If the liquid itself is cloudy rather than the outside surface being foggy, the pen is compromised.
That said, a frozen-and-thawed pen can still appear clear. Appearance alone does not guarantee safety. If you have any reason to believe the pen reached freezing temperatures, the safest choice is to discard it.
Getting a Replacement
If your Wegovy pen looks abnormal (cloudy, discolored, or containing particles), you can contact Novo Nordisk’s Patient Customer Care Center at 1-833-934-6891 to request a replacement. If the pen froze during shipping or because of a pharmacy storage issue, contact the pharmacy as well, since they may be responsible for replacing it at no additional cost.
For pens that froze due to your own storage conditions, replacement policies vary. Your prescriber’s office or insurance plan can help you navigate getting a new pen covered. Given the cost of Wegovy, it’s worth making the call rather than assuming you’re out of luck.
How to Dispose of a Damaged Pen
A frozen Wegovy pen still contains a needle and medication, so it needs proper disposal. Place the pen (with its cap on) into a sharps disposal container. If you don’t have a commercial sharps container, you can use a heavy-duty plastic household container like an empty laundry detergent bottle. Make sure it has a tight-fitting, puncture-resistant lid, stays upright, won’t leak, and is labeled as hazardous waste.
Novo Nordisk also offers a Drug Disposal Program where you can mail back unused medications in a return container. Needles and syringes should not go in the mail-back container, but the pen body and cartridge can.
Proper Storage to Prevent Freezing
Wegovy pens should be stored in the refrigerator between 36°F and 46°F (2°C to 8°C), ideally in their original carton. Avoid placing them against the back wall of the fridge or directly below a freezer vent, where temperatures can drop below the safe range. A simple refrigerator thermometer placed near your pens can catch cold spots before they become a problem.
If you take a pen out of the fridge, it can stay at room temperature (between 46°F and 86°F, or 8°C to 30°C) for up to 28 days, as long as you haven’t removed the pen cap. After 28 days at room temperature, or if the temperature exceeds 86°F, the pen should be discarded.
Keeping Wegovy Safe During Travel
Travel is one of the most common times pens accidentally freeze. The cargo hold of an airplane can reach well below freezing, so always pack Wegovy in your carry-on bag, never in checked luggage. You’re permitted to bring injectable medications through airport security with your prescription documentation.
A thermal or insulated case helps keep pens in the right temperature range, but there’s an important detail: do not place the pen directly against an ice pack. Direct contact with ice or frozen gel packs can freeze the medication just as easily as leaving it outside in winter. Wrap ice packs in a cloth or use a case with a built-in barrier between the cooling element and the pen compartment.
In a car, avoid the trunk and glove compartment, both of which swing to temperature extremes. Keep the pen inside the passenger cabin, ideally in an insulated pouch. During winter road trips, don’t leave Wegovy in the car overnight. Temperatures inside a parked vehicle can drop to match the outside air within a few hours.