Perhaps you stocked up when at-home COVID-19 test kits were hard to come by, before the U.S. federal government started a program to mail some to each household. Or maybe you found a bunch of test kits for a good price at your local pharmacy. Or bought a few when insurance companies started reimbursing the cost.
In any case, if you have a pile of COVID-19 test kits at home, be sure to check the expiration date on the box before using them. The tests do expire, and become more likely to report a false negative result after the expiration date, says Jared Auclair, director of the Biopharmaceutical Analysis Training Lab at Northeastern.
“COVID-19 tests that are past their expiration dates should literally be thrown out,” Auclair says. “They’ll be less potent and more likely to be inaccurate.”
Unlike food labels—which provide a variety of information about when the food will be freshest and taste best but not necessarily when it actually spoils—medical labels indicate crucial information about when the medicine (or test kit) can and can’t be used.
“When you buy milk, oftentimes the expiration date is when you need to buy it,” Auclair says. “COVID tests—and medicines in general—that have expired are all junk. They need to go in the trash.”