One of the biggest frustrations for CGM users is the warm-up period — that one to two hours when your new sensor is starting up and you’re left without any glucose data. Luckily, the warm-up time is only 30 minutes with Dexcom G7—but what if you could completely eliminate that waiting time?

Well, with the Dexcom G7, you can! In the video above, I show how to stack sensors so you have zero downtime when switching from one to another. It’s a simple trick that ensures continuous glucose tracking without interruptions.

Here’s how it works:
Before your current sensor expires, you can apply a new G7 sensor on a different site while the old one is still active. The new sensor will go through its 30-minute warm-up period while your old sensor continues to provide readings. Once the warm-up finishes, you can switch over instantly to the new one—no gaps, no lost data.

Dexcom doesn’t officially advertise stacking as a built-in feature, but many experienced users have found it to be an effective workaround. Just remember to rotate your sensor sites to keep your skin healthy and accurate readings consistent.

If you want to see this in action, I walk through the exact step-by-step method in the full video — including timing, site choices, and tips to avoid common mistakes. On my YouTube episode above, watch Dexcom G7 ZERO Warm-Up With Sensor Overlap to see the live demo and try it yourself.

Disclaimer: Diabetech content is not medical advice—it’s for educational purposes only. Always consult with a physician before making changes to your healthcare. Also, Tandem Diabetes currently advises users that they don’t do this due to the possibility of multiple CGMs being read.