Good question: When do at-home COVID test kits expire?

ROCHESTER, N.Y. — Here’s the answer to a good question about at-home COVID tests. What is the expiration date for the test kits you picked up from the store or the free ones from the federal government that showed up in the mail?

You may be like me, have some just sitting in the cabinet at home. But how long are they truly good for? Will they work this fall and winter?

This is one of the several emails we’ve received about just that: “We have the free antigen rapid test (orange and white box) at-home test kits. I’ve noticed expiration dates on the back of each box. Can they be used after the expiration date and if so, for how many months are they good for after the expiration date? Would hate to toss if they can still be used!”

For most of you, yes, you can still use them well past the date printed on the box. You’re likely to see two dates on the box. The first, when the kit was assembled and the second, the original expiration date, which is kind of a moving target.

The Food and Drug Administration put out an FAQ page to explain. Typically, federal health officials authorize an at-home COVID test kid shelf-life of about four to six months from the time the test was made.

But once the test manufacturer has more “stability testing results”, such as 12 or 18 months, the company can ask the FDA to authorize a longer shelf-life. That’s happened for a lot of these test kits.

While many have been extended, Dr. Emil Lesho from Rochester Regional Health told me why they won’t last forever.

Somers: “What in these tests, with the expiration date, what changes to make them less reliable on a scale that fades away?”

Lesho: “The chemicals on the strip, one of the chemicals is sort of a protein so that can degrade.”

Let’s say, you’re exposed and have symptoms. If you take an “expired” test and it comes back positive, doctors say don’t question it. But if it’s negative, the further away from the date you get, be cautious. Get another test done somewhere else.

You can always go online to see if your brand of the test has a new extended expiration date.

If you have a good question that you want us to answer, email Brennan Somers at GoodQuestion@whec.com.