Narcan (naloxone) nasal spray has a shelf life of four years for products manufactured after January 2024. Older units still on shelves may carry a two- or three-year expiration date, depending on when they were produced. The expiration date printed on your specific package is the one that applies to you.
How the Shelf Life Has Changed
Narcan’s official shelf life has been extended twice. The original product carried a two-year expiration. In August 2020, the FDA approved an extension to three years. Then in January 2024, the manufacturer extended it again to four years for all newly produced units of the 4 mg nasal spray.
These extensions only apply to products made after the approval dates. If you bought Narcan before January 2024, your package still carries its original expiration date, whether that’s two or three years from manufacture. Always go by what’s printed on the box.
How to Store It Properly
Narcan should be stored between 59°F and 77°F (15°C to 25°C), with brief temperature swings acceptable in the range of 39°F to 104°F. That means a medicine cabinet, desk drawer, or glove compartment in mild weather all work fine. Avoid leaving it in direct sunlight or in a car during summer heat for extended periods.
That said, the nasal spray device is surprisingly resilient. A study testing the spray mechanism at temperatures ranging from -20°F to 160°F found no meaningful difference in the volume of medication dispensed. The device worked correctly even at those extremes. This matters because many people carry Narcan in backpacks, cars, or outdoor settings where temperature control isn’t always possible.
Does Narcan Still Work After It Expires?
Yes, and this is one of the most important things to know. A study testing expired naloxone products found that most samples still contained more than 90% of their labeled dose, including products stored for nearly 30 years. The Colorado Department of Public Health and Environment puts it plainly: expired naloxone retains its ability to reverse an overdose effectively and safely for decades beyond its printed date when properly stored.
The bottom line from harm reduction organizations is simple: expired naloxone is better than no naloxone. If someone is experiencing an opioid overdose and the only Narcan available is past its expiration date, use it. The drug doesn’t become dangerous after expiration. It may lose some potency gradually over time, but even decades-old samples have tested well above the threshold needed to work.
Signs Your Narcan May Be Degraded
For injectable forms of naloxone (liquid in a vial or pre-filled syringe), check the solution before use. Do not use it if the liquid has changed color, looks cloudy, or contains visible particles. These are signs the medication has broken down, and you should replace it.
Nasal spray devices are sealed and you can’t inspect the solution inside, which is one reason the printed expiration date and proper storage matter. If the packaging is damaged, punctured, or has been exposed to extreme conditions for long periods, consider replacing it when possible.
Replacing and Disposing of Expired Narcan
Even though expired Narcan still works, it’s worth replacing it periodically so you always have the most reliable product on hand. Many pharmacies, community health programs, and harm reduction organizations distribute Narcan for free, making replacement easy.
When you do replace an expired unit, the FDA recommends bringing it to a drug take-back location, which you can find at many pharmacies and police stations. Some locations also offer prepaid mail-back envelopes. If neither option is available, the general guidance for disposing of medications in the trash is to mix them with something unappealing like dirt, cat litter, or used coffee grounds, seal the mixture in a plastic bag, and throw it away. However, nasal spray devices may have product-specific disposal instructions, so check the packaging or ask a pharmacist.
A practical approach: when you get a new Narcan, write the expiration date somewhere visible, like on a calendar reminder or phone alert, so you know when it’s time to pick up a replacement. Keep the expired one as a backup until the new one arrives.