According to health experts, you should not use an at-home COVID diagnostic test if it’s beyond the expiration date. Some parts of the tests are meant to break down over time. If you use one that’s gone through this degradation, it could provide you with inaccurate or invalid test results.
“I wouldn’t recommend using a diagnostic test after the expiration date,” Heba Mostafa, MBBCh, PhD, an associate professor of pathology and the director of the Molecular Virology Laboratory at The Johns Hopkins Hospital, told Verywell. “There will be concerns about the accuracy of the results.”
Asma Tekbali, MPH, an infection prevention specialist at Lenox Hill Hospital, told Verywell that some at-home COVID tests can be used past the expiration date—especially if the kits and their contents have not been destroyed or altered in any way.
However, extending the expiration date only applies to certain brands of COVID tests. According to the Food and Drug Administration (FDA), a COVID test’s expiration date might be extended if the manufacturer provides data that supports extending its shelf-life beyond the date that was first authorized.
In other words, if a manufacturer can prove a test still works, it might be safe to extend its expiration date.
“Fortunately, study results found that many rapid at-home tests were still accurate beyond their expiration date,” said Tekbali. “Previously, many tests had a shelf life between four to six months, but some have been extended to 12 to 15 months. Continued studies may extend these dates further.”
Where Can I Find the Expiration Date on My COVID Test?
According to Mostafa, you can usually find a test’s expiration date or shelf-life on the box that it came in. Expiration dates might also be on specific items in the test kits.
Some tests that have received extended expiration dates include:
BinaxNOW COVID-19 Antigen Self Test (Abbott Diagnostics Scarborough, Inc. ) Metrix COVID-19 Test (Aptitude Medical Systems, Inc. ) CLINITEST Rapid COVID-19 Antigen Self-Test (Siemens Healthineers)
If your test has two different dates—for example, one date on the outside of the box and another on a bottle of liquid inside it—experts recommend going with the date on the test box or packaging. That date is intended to show the shelf life of the entire kit.
“The expiration date on the box should be considered the expiration date of the actual test,” said Mostafa. “What is listed on an individual component reflects the expiration date for that component only and should not be used.”
How Reliable Are Expired Tests?
Expired COVID tests may not be as accurate or as reliable as ones that have yet to reach their expiration date.
“Certain components of the kit may degrade over time and provide inaccurate results,” said Tekbali, “This all depends on the brand—each manufacturer has a different shelf life.”
Mostafa added that more research is needed on the accuracy of tests that have reached or passed their expiration dates.
“We can not know the answer without additional experiments,” said Mostafa. “Sometimes, the manufacturers do stability experiments and extend the expiration dates based on their results.”
What Other Factors Can Make COVID Tests Less Accurate?
Factors other than expiration dates can also affect a test’s effectiveness and accuracy, including changes in temperature and long exposures to hot or cold.
“Each test has a different temperature range and exposure to extreme temperatures outside of these ranges may affect the accuracy,” said Tekbali.
According to the FDA, most tests should be taken in an environment that is between 59 to 86 degrees Fahrenheit, unless otherwise stated in the test kit’s instructions.
Most at-home COVID tests were developed to be able to withstand being in different temperatures—for example, when being shipped during the summer or winter. However, the FDA said that taking a COVID test while it’s still cold or in an environment that’s hotter than expected could compromise the results.
“Storage temperature is an important variable that impacts the stability of an assay,” said Mostafa. “In the lab, we keep a very close track of how we store assays. The instructions for storage and use have to be adhered to for the most reliable results.”
On its website, the FDA said that long exposure to high temperatures can also affect a test’s results. For example, if the test was delivered and left on your porch in direct sunlight for several days during hot, summer weather, the FDA would recommend you don’t use it.
How Else Can I Determine If a Test Can Still Be Used?
Each COVID test has a built-in quality control line that assures that the test result is valid. If the line does not develop, experts say that you can’t trust the results of the test, despite its expiration date or other factors like temperature control.
“Each assay has an internal control to assure that the result is valid,” said Mostafa. “If this control is not valid, the assay should not be used even if the kit is still within its expiration date.”
Tekbali said there are also other factors that can be used to help make sure at-home tests are accurate. Of particular importance is making sure that the sample collection process is done correctly and that test’s instructions are followed closely.
“Remember that even if you test negative but are symptomatic, it’s best to seek confirmatory testing from a medical provider,” said Tekbali. “Additionally, many different respiratory diseases are being spread this season—such as the flu or RSV. So, don’t assume a negative at-home test puts you in the clear!”
The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.
However, some COVID tests have received extended expiration dates because the manufacturers provided data to support a longer shelf life. You can check your test’s most up-to-date expiration date on the FDA’s website.
