While studies have documented the rise of GLP-1 overdoses as well as unreported side effects and other risks, little research has been done on the effects of improper storage of the weight-loss drugs. Yet Reddit is rife with patient concerns about improper storage — ie, keeping the drug above or below the recommended temperature for a period of time. 

Medscape Medical News spoke with Andrew Fuchs, PharmD, director of practice experience at Touro College of Pharmacy in New York City, about various common storage scenarios that may strike fear among patients and whether their concerns are justified.

Too Hot, Too Cold?

According to the package insert, Wegovy can be stored at room temperature (up to 86 °F/30 °C) for up to 28 days, while Zepbound, depending on the specific injector configuration, can be stored at room temperature for either 21 or 30 days.

“Consider this the baseline for how the manufacturers studied these medications and the conditions under which they can guarantee potency,” Fuchs said. This framework should be kept in mind when evaluating individual situations.

Manufacturers cannot guarantee potency when a medication is stored outside the recommended conditions because it may degrade and lose effectiveness, he noted. “That does not mean it becomes toxic or dangerous, but it may not provide the full therapeutic benefit while still causing side effects.”

In a hot garage. In August 2026, a Zepbound user discovered that their syringes had been left in a hot, uninsulated garage from Tuesday until Friday. The user said it had been 90 °F or higher outside and they had no thermometer, so they couldn’t establish whether the medication stayed below 86 °F. They took the dose anyway and reported, “The medication seems to have survived because I felt like I normally do the day of and day after shot day.”

Fuchs said, “Garages can become extremely hot and easily exceed 86 °F in some climates. The challenge is that we cannot know exactly how hot the medication became over those 3 days. It may have remained within the recommended range, or it may not have.” Using the syringe is unlikely to cause harm, although effectiveness could potentially be reduced, he noted. “The fact that the patient experienced their usual post-dose effects suggests the medication may not have been significantly affected, if at all.”

In a hot car. Another user picked up Zepbound at 11 AM, put it in the car’s glove compartment, and remembered it around 2 PM. The outside temperature was 73 °F, and the medication felt warm but not hot. The user wrote: “Do you think I will be okay to take it next week?”

Fuchs said the outdoor temperature was not excessively high, and the medication was not exposed to direct sunlight, which would have increased the temperature further. “This may be a reasonable situation in which to accept the risk and use the medication.”

14-hour road trip. A Zepbound user asked how to transport a dose on a 14-hour road trip and whether it can go back into the refrigerator at the hotel.

Fuchs said, “Road trips are one of the most common storage questions pharmacists receive. Just because the outside of a car trunk becomes very hot does not necessarily mean the inside of a well-insulated container reached the same temperature.” This would be especially true if the vials are stored with ice packs or otherwise protected from the surrounding heat. 

“The worst-case scenario is reduced effectiveness, not toxicity,” he said.

The refrigerator shut off for a day. A Wegovy user reported that their refrigerator accidentally shut off for about a day. “The medication didn’t become hot, wasn’t exposed to sunlight, and wasn’t frozen, but obviously wasn’t refrigerated.”

Fuchs said, “Even if there was a power outage, an unopened refrigerator can maintain a relatively stable temperature for a period of time.” If the refrigerator door stayed closed, it’s unlikely the temperature increased enough to significantly affect the medication. “If a patient wants absolute certainty, obtaining a replacement may offer peace of mind, but there is a good chance the medication remained within acceptable storage conditions.”

Refrigerator fluctuations. Another Wegovy user bought a refrigerator thermometer and discovered that the shelf where the medication was stored fluctuated from 28 °F to 55 °F. The person wrote, “Have I secretly been deactivating my Wegovy these past few months?”

Fuchs said, “Freezing is a greater concern than heat because these medications are protein-based products, and freezing can alter their structure and potentially reduce effectiveness.”

Both Lilly and Novo, manufacturers of tirzepatide and semaglutide, recommend throwing away a pen if it has been frozen.

However, Fuchs said if a patient isn’t sure if the pen is frozen, it depends on their comfort level. “Because the temperature fluctuated, we cannot know whether the medication actually froze. The medication may be less effective, but it is unlikely to cause harm beyond potentially not delivering the expected results.”

‘Wrong shelf’ anxiety. Another Wegovy user asked, “Where in the fridge are you storing your Wegovy? I’ve been storing mine in the meat and cheese drawer, but then I don’t have enough room for my meat and cheese.”

Fuchs said, “The middle shelf of the refrigerator generally is the most stable location because refrigerators are not designed to maintain the exact same temperature in every area.” For the most accurate storage guidance, refer to the package insert that comes with their medication. “For example, the Ozempic package insert specifically states, ‘Do not store in the freezer or directly adjacent to the refrigerator cooling element.’ This means there is some truth to the idea that there is a ‘sweet spot’ in the refrigerator. The goal is not necessarily to find the perfect shelf, but rather to avoid locations where the medication could freeze.”

“Patients should be intentional about where they store these medications,” he added. “Placing a pen in the middle of the refrigerator is generally a good choice, but if it is sitting next to frozen food or beneath an item being thawed, there is still a risk of exposing it to excessively cold temperatures.”

Frozen vial? A user getting ready to take their first dose of Wegovy discovered a refrigerator thermometer reading about 1 °C/ 34 °F, became worried that the vial had frozen, and asked Reddit group members whether injecting it would be dangerous or merely make it less effective.

Fuchs said that while 1 °C is above, though close to, freezing, it does not necessarily mean the medication froze. “The likelihood is that it did not freeze, although there is still some uncertainty. The question becomes whether the patient is comfortable using it despite that uncertainty, [since] the medication may not be in the ideal condition that the manufacturer studied and can confidently stand behind.”

Warm shipments. A post in the compounded-tirzepatide subreddit states, “Everyday in this sub we are seeing multiple posts about medications arriving warm, shipping delays, melted ice packs, and concerns about whether the medication is still safe to use.” The post had 264 upvotes and was updated on September 28, 2026.

Fuchs said, “I would be substantially more cautious in this scenario. Compounded medications are non–FDA-approved products without manufacturer-supported stability data and clearly defined storage recommendations. With compounded products, stability information may be much more limited and can vary significantly between compounders.”

Patients should contact the compounding pharmacy and ask whether stability data are available for their specific preparation, he advised. “Depending on the information provided, it may still be reasonable to use the product. Some compounding pharmacies perform extensive stability testing and may be able to provide reassurance.”

“In this case, the issue appears more likely to be related to shipping or packaging rather than something the patient did wrong. Because of that, the compounding pharmacy may accept responsibility and replace the medication. It’s always worth contacting them first before making a decision.”

Bottom line. “In nearly all of these cases, the primary concern is reduced potency rather than toxicity,” Fuchs said. “The challenge is that once a medication has been stored outside the manufacturer’s recommendations, no one can say with certainty how much effectiveness, if any, has been lost. Patients should weigh the potential risk for reduced efficacy against the cost and inconvenience of replacement, ideally in consultation with their pharmacist or physician.”

Fuchs reported having no conflicts of interest. 

Marilynn Larkin, MA, is an award-winning medical writer and editor based in New York City whose work has appeared in numerous publications, including Medscape Medical News and its sister publication MDedge, The Lancet (where she was a contributing editor), and Reuters Health.