Dexcom G7 15 Day vs 10 Day: How to Tell Them Apart
We buy sealed diabetic supplies for cash. We do not sell supplies.
You can tell a Dexcom G7 15 Day sensor from the 10-day one by reading the name on the front of the box. Dexcom sells the longer-wear product under the name Dexcom G7 15 Day, so look for "15 Day" in the name. If it's not there, you most likely have the regular 10-day sensor.
Selling? See how we buy Dexcom G7.
This page is general information, not medical or legal advice. Talk to your doctor or pharmacist about your own care.
You don't need to open anything. In fact, you shouldn't. Everything you need is printed on the outside.
What's the real difference?
Both are G7 sensors made by Dexcom. They look alike, but they're cleared for different wear times and different ages.
| 10-day sensor | 15-day sensor | |
|---|---|---|
| Wear time | 10 days plus a 12-hour grace period | 15 days plus a 12-hour grace period |
| Ages | 2 and older | Adults 18 and older |
| Reported MARD | 8.2% | 8.0% |
| FDA clearance | Came first | April 10, 2025 |
MARD is an accuracy score from the maker's own studies. A lower number means readings were closer to lab values.
The grace period is extra time after the sensor session ends. It gives you a window to swap in a new sensor without a gap.
One more fact helps set expectations. Dexcom says about 26% of 15-day sensors may not last the full 15 days when used as labeled. So don't be surprised if one ends a little early.
Where do I look on the box?
Check these three spots, in this order:
- The front of the box. Read the product name. "15 Day" in the name means the longer sensor.
- The label near the barcode. You'll see a REF number, a LOT number and a date. The REF number points to the exact product version.
- The hourglass symbol. The date next to it is the use-by date. That symbol comes from the ISO 15223-1 standard for medical device labels.
Not sure what you're reading? Our guide to finding the REF, LOT and expiration date walks through each symbol, one at a time.
If the label is hard to read, use daylight. Hold your phone close and tap the screen to focus. Then zoom in on the photo. Small print is much easier to read that way.
A real-life example
Say your doctor moved you from the 10-day sensor to the 15-day one. Your pharmacy mails the new boxes, but a few old ones are still in your hall closet. From across the room, they look the same.
Line them up on the kitchen table and read each front. Put the boxes with "15 Day" in one stack and the rest in another. Then check the date on each one and write it down.
Now you know exactly what you have. You didn't break a single seal, and the whole job took about five minutes.
Why buyers care about G7 15 Day
Buyers treat the two as separate products. They can get different offers, so getting the version right matters.
A clear photo of the box front and the label lets a buyer quote you correctly the first time. It also saves you a second round of texts and photos.
If you have both kinds, say so up front. Tell the buyer how many boxes of each you have, and which dates go with which stack.
How should I store them?
Dexcom says to keep sensors in their sterile packaging and store them between 36°F and 86°F. Don't leave them in a parked car on a hot day, and don't freeze them.
That matters here in Southern California. A closed car in July gets much hotter than 86°F. Keep the boxes indoors, in a closet away from windows and heaters.
Use the oldest dates first. That way, nothing sits on the shelf until it's too late.
A simple habit helps. When a new shipment comes, put it at the back of the shelf. Move the older boxes to the front. You'll grab the right one without thinking about it.
What else should I check?
Before you ask anyone for a quote, run through this list:
- The box is sealed, with no tears or cuts in the seal.
- The box isn't crushed, wet or stained.
- The date next to the hourglass hasn't passed.
- The box isn't marked NOT FOR RESALE.
- The pharmacy sticker is still on. Peeling it can tear the label.
If you want to hide your name, black it out with a marker. Keep the marker on the pharmacy sticker only, and don't cover the date or the REF number.
Then take three photos. Get one of the front of each box, so the name shows. Get a sharp close-up of the label, with the REF, LOT and date in focus. Finish with one group shot that shows your total count.
That's all a buyer needs to give you a real number. It also gives you a record of what you had, which is handy if you mail the boxes later.
Still not sure which version you have? Send the label photo and ask. A quick look usually settles it.
Keep reading
Questions
How do I know if my G7 is 15-day or 10-day?
Read the product name on the front of the box. The longer sensor is sold under a name that includes "15 Day."
How long does the 15-day G7 sensor last?
Dexcom says it lasts up to 15 days plus a 12-hour grace period. Dexcom also says about 26% of sensors may not last the full 15 days.
Can kids use the 15-day G7?
The 15-day sensor is cleared for adults 18 and older. The 10-day sensor is cleared for ages 2 and up, so ask your doctor which fits.
Should I open the box to check the sensor?
No. Everything you need is printed on the outside. An opened box can't be resold, so keep it sealed.
Have extra G7 sensors to sell?
We buy sealed, unexpired Dexcom G7 sensors, both the 10-day and the G7 15 Day. In San Bernardino and Riverside County, we meet you in a public place and pay cash, Zelle, Venmo or PayPal. Anywhere else in the U.S., you can mail them in. We never charge you a fee. Send a photo of the box front and label to get a quote.