I have diabetes and just got a Dexcom G6 continuous glucose monitor recently. This CGM never requires calibration, which seems almost impossible to me. Because the CGM sensor never contacts blood (hopefully), it has to measure interstitial glucose levels. In the past, I was always told that interstitial glucose was a lagging indicator of blood glucose and that its relationship to bg was not constant but drifted over time. I guess that's just not true?

So I tried to look up the technology used in the G6, and I couldn't find anything. A few articles discussed the various CGM technologies, with the most popular involving oxidation of glucose with a native enzyme or directly on a catalyst. But I couldn't figure out which one the G6 actually uses. Does anyone know where I could find that out? Or just how CGMs work more generally?