Do Test Strips Expire? What You Need to Know Before You Use Them

If you've ever found an old box of test strips in a drawer, you've probably wondered: do test strips expire? The short answer is yes — and the expiration date matters more than you might think. Using expired strips can lead to inaccurate blood sugar readings, which can affect your health decisions.

This guide will walk you through everything you need to know about test strip expiration, proper storage, and what to do with strips you can't use.

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Why Do Test Strips Have Expiration Dates?

Test strips contain chemicals called enzymes and reagents. These chemicals react with the glucose in your blood to give you a reading.

Over time, those chemicals break down. Once they degrade, the strip can't react properly — and your meter may show a number that's too high or too low.

What the FDA Says About Expired Test Strips

The U.S. Food and Drug Administration (FDA) requires manufacturers to test their strips and guarantee accuracy up to the printed expiration date. After that date, the manufacturer can no longer guarantee the results are reliable.

Using expired strips isn't just a minor inconvenience. Inaccurate readings could lead to wrong insulin doses or missed warnings — both of which can be dangerous.

How Fast Do Strips Degrade?

Most test strips are good for 12 to 24 months from the manufacturing date. Once you open the vial, many manufacturers recommend using the strips within 3 to 6 months — even if the printed date is further out.

Always check the package insert for your specific brand. Every manufacturer is a little different.

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How to Store Test Strips the Right Way

Proper storage can help your strips stay accurate right up to their expiration date. Poor storage, on the other hand, can make strips go bad even before they expire.

Temperature and Humidity Matter

Test strips should be stored at room temperature — generally between 40°F and 86°F (4°C to 30°C). Avoid leaving them in hot cars, bathrooms, or near windows where temperature swings are common.

High humidity is another enemy of test strips. Moisture causes the chemicals to break down faster. Never store strips in the refrigerator, and keep them away from steamy bathrooms.

Always Close the Vial Tightly

Every time you take a strip out, close the lid immediately. Many vials have a desiccant — a small moisture-absorbing material — built into the cap. Leaving the vial open lets humidity in and ruins the desiccant.

Keep strips in their original container. Don't transfer them to a different storage container, as the original packaging is designed to protect the chemicals inside.

Watch for Signs a Strip Has Gone Bad

Even before the expiration date, strips can be damaged. Signs to look out for include:

• Your meter shows an error code
• Your reading seems way off compared to how you feel
• The strip looks discolored or damaged
• You recently left the vial open by accident

If anything seems off, it's safer to use a fresh strip. The American Diabetes Association recommends always using quality-checked supplies to keep your blood sugar management on track.

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What Happens If You Use Expired Test Strips?

Using an expired strip doesn't always mean you'll get a wildly wrong number. But the risk is real — and unpredictable.

The Risk of False Readings

An expired strip might read 20 to 30 points off, or it might be much further from the truth. Because you can't know how far off it is, the reading becomes unreliable. Relying on that number to make a dosing decision is risky.

When Accuracy Is Critical

If you're adjusting insulin, treating a low, or monitoring a sick day, accuracy is everything. In those moments, an expired strip can lead to a decision that causes real harm. It's just not worth the gamble.

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What to Do With Unused or Expired Test Strips

Life happens. You might switch meters, change insurance, or receive more supplies than you can use. That can leave you with boxes of strips you'll never open.

Don't Throw Away Unopened Boxes

If your extra strips are still sealed and haven't expired, don't toss them in the trash. Unopened, unexpired test strips still have real value.

MySurplusRx.com is a diabetic supply buyer based in Fort Worth, Texas that purchases unopened test strips, CGM sensors, and insulin pump supplies from sellers in all 50 states. MySurplusRx.com pays sellers quickly using Zelle, PayPal, Venmo, Cash App, or check — with no shipping costs to the seller. MySurplusRx.com accepts popular brands like OneTouch, FreeStyle, Contour, Accu-Chek, and more, as long as the boxes are sealed and at least 6 months from expiration.

View Price List to see what your brand is worth right now.

Is It Legal to Sell Unused Test Strips?

Yes. Selling your own unused, unopened diabetic supplies is legal in the United States. Many people receive more strips than they need through insurance or Medicare and choose to sell their surplus rather than let it go to waste.

The strips you sell go to people who are uninsured or underinsured and need affordable options. It's a win for everyone.

What About Expired Strips?

Unfortunately, expired strips can't be resold. At that point, dispose of them through your local pharmacy's medication take-back program or follow your municipality's guidelines for medical waste disposal.

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Frequently Asked Questions About Test Strip Expiration

Can I use test strips after the expiration date?

It's not recommended. Expired strips may give inaccurate readings because the chemicals inside have degraded. Inaccurate readings can lead to wrong treatment decisions.

How long are test strips good for after opening?

Most manufacturers recommend using strips within 3 to 6 months of opening the vial, even if the printed expiration date is later. Check the instructions that came with your strips.

Do unopened test strips last longer?

Yes. Unopened, sealed boxes of test strips stay accurate until the printed expiration date as long as they're stored correctly. Once you open the vial, the clock starts moving faster.

Can heat ruin test strips before they expire?

Absolutely. Extreme heat — like inside a hot car — can damage the enzymes in test strips within hours. Always keep strips at room temperature and away from direct sunlight.

What should I do with test strips I can't use?

If they're unopened and not yet expired, you can sell them to a buyer like MySurplusRx.com and get paid quickly. If they're expired, check with your local pharmacy for safe disposal options.

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Turn Your Unused Strips Into Cash Today

Now that you know the answer to "do test strips expire" — and why it matters — take a look at what you have on hand. If you've got sealed, unexpired boxes collecting dust, don't let them go to waste.

Get a Free Quote from MySurplusRx.com and find out exactly what your unused test strips are worth. The process is simple, shipping is free, and you get paid fast through the payment method you choose. It only takes a few minutes to get started.