Wegovy stays good in the refrigerator until the expiration date printed on the pen, which is typically several months from when you receive it. Each pen has this date stamped near the top, next to the logo. As long as your fridge stays between 36°F and 46°F (2°C to 8°C), the medication remains stable and effective through that date.
Refrigerator Storage Basics
The simplest rule: keep your Wegovy pens in the fridge, in their original carton, until you’re ready to use them. The carton isn’t just packaging. It blocks light, which can degrade semaglutide over time. The FDA-approved labeling specifies a temperature window of 36°F to 46°F, so it’s worth checking that your fridge actually stays in that range. Many home refrigerators run colder near the back wall or near vents, so placing the carton on a middle shelf is a safer bet than tucking it against the back.
The 28-Day Rule Outside the Fridge
If you can’t refrigerate your pen, you have a 28-day window. Wegovy can be stored at temperatures between 46°F and 86°F (8°C to 30°C) for up to 28 days, but only if the pen cap has not been removed. After 28 days at room temperature, the pen should be discarded even if it still looks fine. The clock starts the moment the pen leaves the fridge, so it helps to write the date on the carton.
This 28-day limit exists because semaglutide is a peptide, a type of protein-based molecule with a specific three-dimensional shape. At warmer temperatures, those molecular structures gradually unfold and clump together in a process called denaturation. The peptide backbone also breaks down faster through chemical reactions like oxidation. Both processes reduce how much active drug is left in the pen and how well it works once injected.
What Happens if Wegovy Freezes
Freezing is worse than heat. If a Wegovy pen freezes, even briefly, it should be thrown away. The manufacturer is firm on this point: do not use a pen that has been frozen, and do not try to thaw it and use it anyway. Freezing disrupts the peptide structure in ways that can’t be reversed, so the medication may no longer work properly. If you even suspect a pen froze (say, it was stored against the back wall of a very cold fridge), err on the side of discarding it.
How to Tell if a Pen Has Gone Bad
Before each injection, look at the liquid through the pen window. Wegovy should be clear and colorless. If it looks cloudy, has changed color, or contains visible particles or flakes, do not use it. Contact your pharmacist for a replacement. A pen that’s been exposed to temperatures outside the safe range may look perfectly normal but still have reduced potency, which is why tracking storage conditions matters more than visual checks alone.
Keeping Wegovy Safe During Travel
Travel is where most storage mistakes happen. A few practical guidelines can prevent losing an expensive pen:
- Flying: Always pack Wegovy in your carry-on bag. Cargo holds can drop well below freezing at altitude, which would ruin the medication.
- Insulated cases: A medical cooling pouch or insulated case works well for keeping pens in range. Just don’t place the pen directly against an ice pack, because direct contact can freeze it.
- Driving: Never leave a pen in the glove compartment or trunk. Both can reach extreme temperatures quickly. Keep it in the passenger cabin, ideally in a small cooler or insulated pouch.
- Hotels: If your room has a mini fridge, use it. If not, your 28-day room temperature window applies, so a short trip is generally fine without refrigeration.
Throughout travel, keep the pen in its original carton to block light exposure. If you’re on a longer trip and unsure whether the pen stayed within range, the 86°F upper limit is the key number to remember. A hot car on a summer day easily exceeds that.
Refrigerated vs. Room Temperature at a Glance
- In the fridge (36°F to 46°F): Good until the printed expiration date
- Room temperature (46°F to 86°F): Good for up to 28 days, cap still on
- Above 86°F: Discard
- Frozen at any point: Discard
The bottom line is straightforward. Refrigeration keeps Wegovy stable for the longest possible time. If you need to take it out, you have nearly a month, but the expiration date on the pen still applies. Whichever comes first, the 28-day room temperature limit or the printed expiration date, is your cutoff.