What Happens When You Use That Expired COVID Test Sitting in Your Medicine Cabinet

Health Points

• Many COVID-19 at-home tests remain accurate well beyond their printed expiration dates, with manufacturers receiving FDA extensions
• Expired tests may produce fainter lines or unclear results, but proper storage in cool, dry conditions helps maintain reliability
• Checking the FDA’s updated expiration date list and following up unclear results with fresh tests ensures accurate diagnosis

If you’ve got a stash of at-home COVID-19 tests tucked away in a bathroom drawer, you’ve probably noticed those expiration dates creeping closer. With many households still holding onto rapid tests from earlier in the pandemic, the question of whether those expired kits still work has become increasingly relevant for Americans over 40 who want to stay prepared for potential exposure.

The good news is that your expired test might still be perfectly usable. Many COVID-19 at-home tests remain effective well past their printed expiration dates, thanks to ongoing stability testing by manufacturers and subsequent extensions granted by the Food and Drug Administration.

“The expiration dates on COVID tests are often conservative estimates,” explains Dr. Michael Mina, former assistant professor of epidemiology at Harvard T.H. Chan School of Public Health. “Manufacturers have continued to study how long these tests remain stable, and many have received FDA approval to extend those dates.”

The FDA maintains an updated list of at-home COVID-19 tests with extended expiration dates on its website. Before tossing that “expired” test, it’s worth checking whether the manufacturer has received an extension for your specific lot number. Some tests initially marked with 12-month expiration dates have been extended to 18 or even 24 months.

Dr. Amesh Adalja, senior scholar at the Johns Hopkins Center for Health Security, notes that proper storage plays a crucial role in maintaining test accuracy. “If you’ve kept your tests in a cool, dry place away from extreme temperatures, they’re much more likely to remain reliable beyond the printed date,” he says.

However, there are some caveats to consider. Tests that have been exposed to heat, humidity, or freezing temperatures may degrade faster than those stored under ideal conditions. If you’ve kept your tests in a garage, car, or steamy bathroom, their reliability may be compromised regardless of the expiration date.

When using an older test, be mindful of potential changes in performance. The test components—particularly the reagents that detect viral proteins—can become less sensitive over time. This might result in fainter test lines or less definitive results, especially if your viral load is low.

“If you use an expired test and get a positive result, that’s generally reliable,” Dr. Mina explains. “The concern is more with false negatives—an expired test might miss a low-level infection that a fresh test would catch.”

If you’re experiencing COVID-19 symptoms or have had a known exposure, health experts recommend using a current test when possible. For routine screening or checking before gathering with vulnerable family members, an expired test is better than no test at all, but consider following up an unclear or negative result with a fresh test if symptoms develop.

The visual components of the test can also offer clues about its condition. Before using an expired test, inspect the test strip and reagent solution. If you notice discoloration, cloudiness in the liquid, or any crystallization, the test has likely degraded and should not be used.

For those managing chronic health conditions or caring for elderly parents, maintaining a supply of current COVID tests remains a practical health measure. Many pharmacies now stock these tests regularly, and they’re often covered by insurance or available at reduced costs through government programs.

“Think of COVID tests like batteries,” Dr. Adalja suggests. “They might work past their expiration date, but you wouldn’t want to rely solely on old batteries in a smoke detector. Keep some fresh tests on hand for when accuracy really matters.”

If you do decide to use an expired test, consider testing twice over a day or two, especially if you’re symptomatic. This can help account for any reduced sensitivity and provides more confidence in the results.

The bottom line is that while many expired COVID tests remain functional, they come with increased uncertainty. Checking for FDA extensions, storing tests properly, and keeping at least a few current tests available provides the best balance of resourcefulness and reliability for protecting your health and that of your loved ones.