The Dexcom G7 15 Day is the newest continuous glucose monitor (CGM) from Dexcom, offering 50% longer wear and upgraded accuracy over the G7 10-day. Dexcom sent over a couple sensors to try and I got a few more from the pharmacy in order to review it. Before we hop into my thoughts, here are the basics…

The sensor is approved for adults 18 and older with type 1 or type 2 diabetes. It is the same physical size (the size of two stacked quarters), uses the same applicator and smartphone app as the 10-day model, and Dexcom says the included overpatch is required for wear (but I don’t find it necessary to last longer on my skin).

The upgraded sensor surprisingly adds an extra 30 minutes to the warm-up time totalling 60 minutes which Dexcom says is necessary in order to achieve peak accuracy and longevity. It has an updated algorithm which promises better accuracy which I’ll get into in just a bit. Currently, it works with the Omnipod 5 and Beta Bionics iLet, and Dexcom is actively working with Tandem to add compatibility with the t:slim X2 and Tandem Mobi.

I came into this review already familiar with Dexcom technology, having used both the G6 and the G7 10-day since I was diagnosed in 2021. Over the last couple of months, I wore four 15-day sensors back to back, putting the extended wear claims to the test. Here is everything I found.