People buy diabetic test strips from unofficial sources, like online marketplaces and independent resellers, primarily because the strips are expensive and insurance coverage often falls short. A box of 100 name-brand test strips can cost $75 to $150 at a pharmacy without insurance, and many people with diabetes need hundreds every month. That gap between what people need and what they can afford has created a thriving secondhand market where unopened boxes sell at steep discounts.
Test Strips Are Expensive and Coverage Is Limited
The core driver is cost. People with type 1 diabetes may need to test their blood sugar 4 to 10 times a day, according to Mayo Clinic guidelines. At the high end, that’s 300 strips per month. Even at the low end of 4 tests daily, you’re going through 120 strips a month. For people with type 2 diabetes on insulin, the testing schedule is similar, often before every meal and at bedtime.
Insurance helps, but not always enough. Medicare Part B, for example, covers up to 300 test strips and 300 lancets every three months for people who use insulin. That works out to about 100 strips per month, which covers someone testing three times a day but leaves a gap for anyone testing more frequently. For people with type 2 diabetes who don’t use insulin, Medicare covers just 100 strips per quarter, roughly one test per day. Doctors can request additional supplies if they document medical necessity, but that process adds paperwork and delays.
People without insurance, on high-deductible plans, or in the Medicare “donut hole” face even steeper costs. When a single box of strips costs more than a day’s wages, buying discounted strips from a reseller starts to look like a reasonable choice.
Where the Surplus Comes From
The supply side of this market exists because many people with diabetes end up with more strips than they need. This happens for several common reasons. A doctor changes someone’s medication, and they no longer need to test as often. A person switches from fingerstick testing to a continuous glucose monitor (CGM), which reads blood sugar automatically through a sensor under the skin. Someone receives a large shipment through a mail-order pharmacy and doesn’t use it all before their prescription changes. Or, in some cases, a family member with diabetes passes away and leaves behind unopened supplies.
These surplus strips are typically unopened, unexpired, and perfectly usable in theory. Sellers list them on Amazon, eBay, Craigslist, Facebook Marketplace, and dedicated test strip buying websites. Some businesses specifically advertise “we buy diabetic test strips” and then resell them at a markup that’s still well below pharmacy retail prices. For the seller, it turns unused medical supplies into cash. For the buyer, it cuts costs significantly.
Who’s Buying and Why
The buyers fall into a few groups. The largest is people with diabetes who simply can’t afford retail prices or whose insurance doesn’t cover enough strips. But there are other buyers too. Some people without a diabetes diagnosis use test strips to monitor blood sugar for personal health tracking or because they suspect they have prediabetes and haven’t yet seen a doctor. Caregivers for elderly family members sometimes buy discounted strips to stretch a fixed income. And in some cases, people in countries with limited access to diabetes supplies purchase strips from U.S. resellers.
The common thread is affordability. When the same sealed box of strips costs $30 from a reseller instead of $100 at a pharmacy, the financial pressure makes the decision feel obvious, even if it comes with trade-offs.
The Risks the FDA Has Flagged
The FDA has issued direct warnings about buying pre-owned test strips. The agency’s concerns center on several specific problems. Strips that have been stored improperly (exposed to heat, humidity, or temperature swings) can give inaccurate readings. Research on thermal stress and test strip performance found that glucose readings could be off by as much as 11 to 16 mg/dL when strips were exposed to temperatures outside their specified storage range, which is typically between about 2°C and 32°C (roughly 36°F to 90°F) depending on the brand. That level of error can lead someone to take too much or too little insulin, with potentially dangerous consequences.
Beyond storage, the FDA warns that opened vials previously handled by another person may carry small amounts of blood, creating a risk of infection. Expiration dates on resold boxes may have been altered or covered up. And some strips sold through unofficial channels aren’t authorized for sale in the U.S. at all, meaning they may be counterfeit or manufactured to different standards. The FDA specifically notes that these products appear on Amazon, eBay, and Craigslist, and recommends purchasing strips only from pharmacies or directly from manufacturers.
For the buyer, there’s no reliable way to verify how a box of strips was stored before it arrived. A sealed box that looks perfectly fine could have spent weeks in a hot warehouse or car trunk, silently degrading the enzyme chemistry that makes the strip work. The resulting inaccurate readings wouldn’t look obviously wrong on the meter. They’d just be slightly off, enough to cause real problems over time for someone making insulin dosing decisions based on those numbers.
Legal Gray Area
Reselling diabetic test strips occupies a murky legal space. Test strips are FDA-regulated medical devices, and some brands are prescription-only. If someone can purchase prescription-only strips without a prescription, the FDA considers those products potentially unauthorized for sale in the U.S. However, there is no broad federal law that explicitly bans individuals from reselling their own unused, over-the-counter medical supplies. Some states have laws regulating the resale of medical devices or requiring specific licenses, but enforcement is inconsistent.
The practical result is a market that operates openly online, with dedicated websites and social media ads, despite the FDA’s warnings. The agency focuses its enforcement efforts on larger operations and products that pose the clearest safety risks, rather than individuals selling a few boxes. This creates the impression that buying and selling strips is fully legal and safe, which isn’t quite the full picture.
What This Market Reveals
The secondhand test strip market is fundamentally a symptom of a pricing problem. Diabetes is a condition that requires constant monitoring, the supplies for that monitoring are expensive, and insurance coverage doesn’t always match the clinical reality of how often people need to test. When Medicare limits a non-insulin-dependent patient to roughly one strip per day but their doctor recommends testing more frequently, the patient faces a choice between paying out of pocket, testing less often, or finding cheaper strips somewhere else.
Continuous glucose monitors are reducing some of this demand by eliminating the need for fingerstick testing entirely for some patients. But CGMs have their own cost barriers, and millions of people with diabetes still rely on traditional meters and strips as their primary monitoring tool. As long as that gap between need and affordability exists, people will keep buying test strips wherever they can find them at a price they can manage.