Do Diabetic Test Strips Expire?
Yes, and the printed date is the whole story. Past it, strips shouldn't be used and can't be sold — but there's an important distinction most people miss between expired and close to expiring, and it's worth real money.
Don't use expired strips
The FDA advises against using test strips past their printed date. The reagent coating degrades, and a degraded strip can read high or low with nothing to indicate the number is wrong. If you're adjusting insulin based on that reading, a bad number isn't an inconvenience — it's a hypoglycemia or hyperglycemia risk.
If you've run out of in-date supplies and can't afford more, talk to your care team or pharmacist. Manufacturer assistance programs and community health centres exist for exactly this, and it's a better answer than testing on strips you can't trust.
Will expired glucose strips read high or low?
Either one — and that is precisely the problem. Expired glucose strips do not read high or low in a predictable direction, which is what makes the question worth answering properly. Two different failure modes push in opposite directions. As the enzyme coating degrades with age, humidity or heat, the reaction weakens and the meter reads falsely low. But electrical drift in an aged strip can push a reading falsely high. Which one you get depends on how that particular strip degraded, and you cannot tell by looking at it.
So the question does not have the useful answer people are hoping for. If expired strips reliably read low, you could mentally add a margin and carry on. They do not. The meter shows a number that looks exactly like a real one, with no error and nothing visibly wrong with the strip — which is what makes it a safety problem rather than an inconvenience.
If you need to know whether a meter and strip combination is reading accurately at all, control solution is the check that answers it. A reading that falls outside the range printed on the vial means the strips, the meter, or both are not to be trusted.
Do blood sugar test strips expire?
Yes, all of them. Every box carries a printed expiration date and it is not a formality — the strip works by a chemical reaction, and the reagent coating that drives that reaction breaks down over time whether the vial has been opened or not. This is true of every brand: OneTouch, Accu-Chek, Contour Next, FreeStyle and TRUE Metrix alike. The date is printed on the vial and usually the outer carton too, normally as a month and year, which means the strips are good through the last day of that month.
Can you use expired test strips?
You shouldn't. Whether you can use expired blood glucose test strips is really a question about whether you can trust the number they produce, and you can't. The FDA advises against using expired strips because the chemical reagents degrade over time, and a degraded strip can read high or low without any indication that it's wrong. If you're dosing insulin off that number, an inaccurate reading is a real safety problem rather than an inconvenience. Talk to your care team if you're stuck without in-date supplies.
What happens if I use expired blood glucose test strips?
The meter gives you a number and you have no way of knowing whether it is the right one. There is no error message, and an expired strip looks identical to a good one. That is what makes it dangerous rather than merely unreliable — a wrong reading in either direction, acted on with insulin, can cause hypoglycemia or leave real hyperglycemia untreated. The FDA's position is not to use them, and the reason is that the failure is silent.
How long are blood glucose test strips good for?
Until the date printed on the vial, assuming an unopened vial stored properly. The actual window varies by brand and by lot, so the only number that matters is the one on your own box — there is no general rule that overrides it. Storage shortens it: heat, humidity and direct sunlight all degrade the reagent faster, which is why a bathroom cabinet and a car glovebox are the two worst places to keep them. Worth noting that the date belongs to the strips, not the meter — glucometers do not expire, strips do.
How long are glucose strips good for once opened?
Often a good deal less than the printed expiration date, and this is the part most people miss entirely. Many vials carry a separate discard-after-opening window — you are meant to write the date you opened it on the label and stop using those strips after that period, even if the printed expiration is still months out. The window varies by brand, so check your box. Strips that come individually foil-wrapped are the exception, since each one stays sealed until the moment you use it.
Can you sell expired diabetic test strips?
No, and nobody legitimate buys them. Wholesalers won't accept them, so there's no resale channel to sell into. Anyone offering to buy expired strips is either reselling them to people who shouldn't be using them or isn't going to pay you. Expired boxes should be disposed of, not sold.
How close to expiration can I still sell them?
Further out than most people assume, and this is where boxes get thrown away unnecessarily. Value drops as the date approaches rather than falling off a cliff at the end — strips with 9 or more months left earn the most, 6 to 8 months still sell, and even shorter dating is often worth something. If the date hasn't passed, it's worth asking before you bin it.
When do test strips expire for a glucometer?
The date belongs to the strips, not the meter — glucometers don't expire, strips do. So the answer is whatever is printed on your vial, which varies by brand and by lot. Worth knowing that the printed date already assumes an unopened vial stored properly, so it isn't a conservative estimate you can safely stretch. Opening a vial shortens things further, and heat or humidity degrade them faster regardless, which is why a bathroom cabinet or a hot car is the worst place to keep them.
How should I dispose of expired test strips?
Used strips and lancets are sharps waste and should go in a proper sharps container, not loose in household rubbish. Unused expired strips aren't sharps and can generally go in household waste, though many pharmacies and county household hazardous waste programs will take them. Your county health department's website is the fastest way to find a local drop-off.
Check the date again before you throw them out
Most boxes we're asked about aren't expired — they're close, and the owner had already written them off. A sealed box with six months left is worth real money to someone paying out of pocket, and it's worthless the day after the date passes. The window closes; it doesn't reopen.
If yours are still in date, here's what we pay for diabetic test strips, and whether it's legal to sell them if you haven't checked that yet. We also buy Dexcom supplies and Medtronic pump supplies, which tend to sit in the same drawer. Storage matters as much as the date — heat and freezing ruin supplies without leaving anything to see.
Already past the date? Dispose of them rather than selling them — used strips and lancets are sharps waste, and your county health department can point you at a local drop-off.
General information, not medical advice. Talk to your doctor, diabetes educator or pharmacist about testing supplies and anything affecting how you manage your blood sugar.