Why You Shouldn’t Keep Epinephrine in a Hot Car
Published: July 30, 2021 Revised: September 17th, 2025
When summer temperatures rise, storing medications safely – especially life-saving ones – is more important than ever. For people at risk for anaphylaxis, a severe allergic reaction, that means storing epinephrine at the right temperature.
Going out, running errands, or traveling? Keeping your epinephrine epinephrine product in your car may seem convenient, but cars can become very hot during the day. Some cars can reach 143.7 degrees F during hot weather. Extreme heat for an extended period can affect the quality of epinephrine. It can make epinephrine products ineffective or cause auto-injectors to malfunction.
Epinephrine manufacturers say you should store your epinephrine product in as close to room temperature as possible. This is between 68 to 77 degrees F. This helps ensure the severe allergy treatment is effective if needed.
Nasal spray: neffy®
The package insert for neffy® says it’s acceptable to store the device in temperatures of up to 122 degrees F, but no more than a few days.
The device should be replaced immediately if kept in high heat (no higher for than 122 degrees F) longer than a few days. You can request a refill for neffy from your healthcare provider every 30 days, or immediately after you have used the device.
The neffy device is pocket-sized – convenient for self-carry.
Auto-injectors
The package insert for epinephrine auto-injectors say a brief stay in temperatures of 69-86 degrees F is permitted.
Epinephrine auto-injectors may lose potency within hours when stored in a hot vehicle, according to a 2019 study.
Short-term exposure to heat in a car on a sunny day can decrease the concentration of epinephrine. If you use a degraded epinephrine auto-injector, it could result in an underdosage of the lifesaving medication.
The most significant reduction of epinephrine concentration occurred when the auto-injector was stored in the glove compartment or cabin shelf under the rear window.
“We want to urge everyone to never expose their EpiPen® to high temperatures or leave them in their vehicles for long periods of time,” says study author Piotr Lacwik, MD. “Underdosage during anaphylactic reaction can have deadly consequences.”
Epinephrine auto-injectors should be replaced immediately if kept in hot temperatures for an extended period.
Additional epinephrine storage tips
Keep epinephrine auto-injectors out of direct sunlight.This can cause the epinephrine solution to oxidize (combine with oxygen, changing the makeup of the drug) and become ineffective. Oxidized epinephrine will appear dark or have solid particles in it.
Epinephrine can also oxidize on its own over time. It’s important to check the solution appearance inside auto-injectors regularly to be sure the liquid inside is clear.
Other epinephrine storage tips include:
- Keep the pack of two nasal sprays or auto-injectors together.
- Use a storage case.
- Check expiration dates to make sure the products are not expired.
If you need to dispose of epinephrine, check the package insert or contact your local government for information on proper disposal. Since auto-injectors have needles, you may need to put it in a secure container and then take it to a designated collection site, pharmacy or hospital.
Reviewed by:
Purvi Parikh, MD, FACAAI, is an adult and pediatric allergist and immunologist at Allergy and Asthma Associates of Murray Hill in New York City. She is on faculty as Clinical Assistant Professor in both departments of Medicine and Pediatrics at New York University School of Medicine.
