You’re standing in your bathroom, feeling that familiar, annoying tickle in the back of your throat. You dig through the medicine cabinet, past the half-empty bottle of Pepto and the band-aids, and finally find it: a dusty box of BinaxNOW COVID-19 tests. You breathe a sigh of relief until you flip it over.
The date on the back says it expired six months ago.
Before you chuck it in the trash and spend $25 on a new pack at Walgreens, wait. There is a very good chance that test is still perfectly valid. Seriously. The "expiration date" on these boxes is often more of a conservative guess than a hard deadline. Because the pandemic moved so fast, the FDA initially set short expiration windows, but as time went on, Abbott (the manufacturer) proved that the chemistry inside lasts a lot longer than they first thought.
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The BinaxNOW Expiration Date Extension: What’s the Real Deal?
Basically, the FDA has been handing out extensions like candy—but only because the data backs it up. Most BinaxNOW Self Tests that originally had a 15-month shelf life were officially bumped up to 22 months.
If your box has an hourglass symbol and a date that has already passed, don't panic. You’ve gotta check the lot number. That little string of numbers next to the word "LOT" is your golden ticket. The FDA maintains a massive, constantly updated database where you can match your lot number to a new, extended date. In many cases, you’re looking at an extra 7 to 12 months of viability beyond what is printed on the cardboard.
How to look it up right now
- Grab your box and find the Lot Number (usually 6 digits).
- Head over to the FDA’s official list of authorized at-home OTC tests.
- Scroll down to Abbott Diagnostics Scarborough.
- Click the "Extended Expiration Date" link to see the PDF containing every single lot number and its true "use-by" date.
Why do these dates keep changing?
It feels kinda sketchy, right? Like, imagine if milk just "got an extension" from the government. But medical diagnostics are different. When BinaxNOW first hit the market, Abbott hadn't actually seen what happens to the reagents after two years because the product hadn't existed for two years.
They did what’s called "stability testing." They kept batches of tests in warehouses and tested them every few months. Every time they proved the tests still caught the virus accurately, the FDA said, "Okay, cool, add another six months to the lifespan."
Honestly, it’s about the antibodies. Inside that little plastic card are gold-conjugated antibodies. They’re biological materials. Over a long enough timeline, they break down or lose their "stickiness," meaning they won't grab onto the virus even if it's there. This is why you get a false negative. The chemistry just gives up.
Can you trust an "expired" result?
Let's say you checked the FDA list and your test is definitely past even the extended date. Should you use it anyway?
If you use a truly expired test and it comes back Positive, you almost certainly have COVID. It’s very rare for a degraded test to spontaneously create a fake positive line. The chemicals failing usually leads to a "blank" result, not a "false" one.
However, if it's expired and you get a Negative, you cannot trust that result. Not even a little bit. If the reagents are dead, they won't show a line even if your viral load is through the roof.
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The Control Line "C" Trap
A lot of people think that if the "C" (Control) line shows up, the test is fine. That’s sort of a myth. The control line only proves that the liquid (the buffer) successfully wicked across the strip. It doesn’t prove that the active antibodies are still sensitive enough to detect the virus.
Storage: The silent killer of your COVID tests
You might have a test that isn't expired yet, but it's still "bad."
If you left your BinaxNOW kit in a hot car during a July heatwave, or if it was delivered to your porch in sub-zero January temperatures, the internal chemistry is likely toast. These tests are meant to be stored between 35.6°F and 86°F (2°C to 30°C).
If the liquid in the little dropper bottle (the reagent) looks cloudy or has evaporated, throw the whole thing away. That stuff needs to be clear and at the right volume to work.
Moving forward: What to do with your stash
If you’ve got a mountain of tests in your pantry, take five minutes to do an inventory. Use a Sharpie and write the New FDA Extended Date in big letters on the front of the box. It’ll save you a lot of googling and stress the next time you wake up with a fever at 2 AM.
Your Action Plan:
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- Check the LOT: Don't trust the printed date. Use the FDA lookup tool.
- Check the liquid: If the buffer solution is gone or murky, the test is trash.
- Trust Positives, Doubt Negatives: If you’re symptomatic but testing negative on an old kit, go get a PCR or buy a fresh pack.
- Dispose properly: No need for biohazard bags for expired tests; they can go right in your regular household trash.
By keeping track of these extensions, you’re not just saving money; you’re making sure you actually have a tool that works when you need it most.