海角社区

Subscribe to the OSS Weekly Newsletter!

What if your COVID tests are expired?

Many of the rapid kits people have in their homes are probably still valid despite the published dates on the box. Here's why.
Image by PHOTO BY JOHN MAHONEY / Montreal Gazette.

This article was originally posted in the


With COVID-19 cases on the rise again, many people were shocked to discover that rapid tests are no longer available at pharmacies. Having blissfully ignored the problem for the past several months, many were left wondering how to get tested and whether their old tests were still effective or were now expired.

Before delving into the issue of expiry dates, rapid tests are still available, just not at pharmacies. They聽聽鈥 the vaccination centres, though some people (children under 17, full-time students, etc.) can still get rapid tests at pharmacies. So if any doubt remains about the validity of your rapid COVID tests, the simple solution is to get a new one.

But many of the rapid tests people have in their homes are probably still valid despite the published dates on the box. Both聽聽and the聽聽in the United States extended the expiry dates to聽

To understand why this happened, we first have to explain聽聽and why this is different from the 鈥溾 date you see on food. Anything with a shelf life over 90 days has no requirement for a date labelling. Less than 90 days requires a 鈥渂est before鈥 date to denote how long it maintains its freshness, taste or nutritional value 鈥 not necessarily when it becomes unfit for consumption. Only certain foods require true 鈥渆xpiration dates.鈥

Medications also have expiration dates. Every year the Drug Enforcement Agency in the U.S. has a聽聽where they collect unused, expired medication from people across the country. In 2023, they collected 332 tons of expired meds.

The worry with expired medication is that they will degrade over time and lose their effectiveness. To judge how long this process will take, companies usually perform聽聽on their new products. They subject them to extreme temperatures and conditions, then extrapolate how long they would last under standard conditions. Many medications may still be fine to use beyond these dates; they just haven鈥檛 been tested to prove the point.

The FDA can聽聽of products by performing updated stability testing, but there鈥檚 rarely a compelling need to do so for most products. An聽聽is that extending the expiry date implies unopened bottles and packaging, as being exposed to ambient air and humidity can accelerate the degradation process.

With the case of COVID rapid tests, the decision to extend the expiry dates is easily understandable. Since many people have unused stockpiles of rapid tests in their homes, not updating the expiry dates would have led to unnecessary waste.

With medication, product degradation can lead to a lack of efficacy or potential harm. An EpiPen that has expired may not save your life if you are having an allergic reaction. With COVID tests, the concern is not so much one of safety. The worry is that the test will produce inaccurate results, mainly false negatives.

A positive result depends on the COVID antigen on your nasal swab聽聽in the test kit to produce a colour change. If the antibodies in the test kit degrade over time, they won鈥檛 generate that reaction to signal a positive test, even if you are sick.

So to the question of whether you can use an expired COVID test, the answer is first to make sure that it actually is expired, because it might not be.

Again, the worry is that an expired test might produce a false negative. False positives are unlikely. So if any doubt remains, the first option is the simplest: Go get a new package at a government vaccination centre when you聽. That will remove all doubt.


Back to top