Are CGM Sensors Accurate?

Because CGMs measure glucose from the fluid between cells, they are less accurate than finger stick devices, which measure blood directly. People with diabetes often use a finger stick reading to help calibrate their CGM, which can increase accuracy.

Practically speaking, if you’re using CGMs for general health and wellness (and not to dose insulin), it’s best to think of the CGM data as directional. Your numbers may vary across brands or even among different sensors from the same manufacturer, but studies have found that the readings are consistent enough to give useful feedback on your diet.

In short, the most valuable way to use a CGM is to focus on the trends in glucose values before and after meals, even if baseline readings are slightly different.

For more info check out the NDSS website

https://www.ndss.com.au/living-with-diabetes/management-and-care/continuous-glucose-monitoring/