The short answer
Store unused, sealed boxes at controlled room temperature — roughly 59 to 86°F — out of direct sunlight and away from humidity. That means an interior closet or a drawer, not a car, not a garage, not an attic, not a bathroom cabinet. Test strips carry an enzyme coating that degrades with heat and moisture, and a degraded strip gives a false reading to whoever uses it next.
The four things that destroy value
- Heat. A closed car in a Georgia August exceeds 140°F. One afternoon is enough.
- Humidity. Bathroom cabinets and unconditioned basements.
- Freezing. Less common here, but a garage in January still does it.
- Direct light. A windowsill will do it slowly.
CGM sensors are the same, with one difference
Dexcom and Libre sensors are stored at room temperature, not refrigerated — a common misconception that leads people to put them in a fridge, which is its own problem. Same rules otherwise: no heat, no car, keep the pouches sealed.
Why we ask
We ask every seller where the boxes have been kept, and it is not a formality. We will not buy heat-exposed stock, because it ends up in the hands of someone dosing insulin off the result. That is the part of this business that has to be taken seriously.
What the record shows
Everything below is quoted or drawn from a primary source, linked so you can check it yourself rather than take our word for it. Full list on our sources and regulations page.
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“You could be greatly overusing or underusing insulin because of an incorrect result. That’s where it would be a really critical health issue.”
— American Diabetes Association — Matt Petersen, Vice President of Medical Information, Reselling diabetes test strips an unregulated ‘gray market’ in US, reported.
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