If you have kept a stock of Covid-19 rapid tests in your bathroom cabinet, you may want to check the labels for expiration dates.
It turns out that these tests can time out and, depending on the brand, will all go wrong at different times. Some may have a shelf life of six months, while others may last up to 15 months. Even though all tests work the same way antigen detection (pieces of viral protein) from a swab sample, they all expire at different times due to the regulatory processes they go through before being sold.
The Food and Drug Administration is responsible for determining the retention period of these tests. For other types of non-Covid tests, manufacturers are allowed to determine shelf life using a process called “accelerated dating”, which speeds up shelf life conditions to see how well they will last in a few weeks.
With rapid Covid tests, however, determining the shelf life takes much longer because it must be done in real time. That means a home Covid test that was developed in 2020 will have to sit on the shelf for two years and then be used in a controlled lab study to see if it’s still effective.
So what does this mean for consumers? Should you throw away and waste the tests you have saved?
Over time, expiration dates are extended based on data collected. Thus, a test that originally predicted that it would expire in six months may become nine or 12 months.
“The date stamped on the label may be different from the actual expiration date, so it’s important to check the FDA website for more information,” says CAN Community Health infectious disease specialist Dr. Douglas Brust.
Most tests have a six-month expiration date. If you have a test that has expired, you can call the manufacturer or check the FDA clearance letters online to see if the date has changed and if it is still valid.
Either way, it’s important to get tested as soon as you experience Covid-like symptoms. Here’s what you can do to make sure the tests you have at home are the most effective.
View FDA regulatory documents online.
Expiry dates are frequently tested and extended. The FDA website has a link for antigen tests and molecular testing showing the latest updates. One brand, BinaxNOW, for example, has data that extends the shelf life from 12 to 15 months.
You can still use home tests that are only a few days out of date if you have symptoms of Covid rather than throwing the tests away. This will also help alleviate test shortages at pharmacies.
Store the tests at room temperature.
Store the tests in dry conditions and do not allow them to freeze or overheat, such as in the car. When shopping for a home test, check the expiration dates in the store and find one with a long shelf life. Pay attention to the date of your current home tests and use those that are about to become expired firs.
If you ordered free tests from the government, make sure they are brought inside the house as soon as possible and not left outside in the heat or cold. Do not use tests that are already open.
“The tests are designed to withstand temperature changes during shipment, but should be brought to room temperature before use,” Brust explains.
When using a test, make sure the control lines appear quickly.
This is an indicator that the test is still working. Medical experts say these tests are very stable. If the control line appears and you take the test within 18-24 months of its date of manufacture, you should assume that the test is working.
Use tests as needed.
Get tested immediately if you have symptoms of Covid-19. If you have been exposed to someone with Covid-19, wait at least five days after your exposure. If your test is negative, test again one to two days after your first test.
“Use tests based on who is sick in your household and don’t use a test after the expiration date listed on the website,” Brust says.
If you plan to go to an indoor event, consider getting tested immediately before the event, especially if you will be in contact with immunocompromised, elderly, or unvaccinated people.
If you test positive, stay home for at least five days and self-isolate. Be sure to let close contacts know you are positive and wear a properly fitted mask around others when needed. Contact your health care provider if you have any concerns about symptoms.
For more information on where to get tested and vaccinated for Covid-19, click here. For more information on home testing, visit Centers for Disaster Control and Prevention website and Food and drug administration website.