Today I put in 3 CGM’s (continuous glucose monitors) to compare them and see which one preforms best.

I have worn all three in the past so I have a good understanding of the ins and outs of each. That said, the results I will be posting over the next week may be different for different people. CGM’s are cutting edge technology so there is room for human error and differences depending on who is wearing it.

Which CGM’s am I wearing?

There are currently 3 CGM’s on the market in the USA. I am wearing them all as follows:

Medtronic’s Revel

Dexcom’s G4 Platinum

Dexcom’s 7+ (has been replaced by the G4 but you can still get sensors if you already have one)

The Rules:

Once calibrated (about 2 hours after insertion) I will test every hour or every time one of the sensors alerts to a high or low, whichever comes first. While sleeping I will test if I am alerted to a high or low (assuming I am awake enough to remember). I will calibrate all 3 at the same time 3 times a day when my blood sugar is steady. Medtronic recommends calibrating that way. Dexcom can be calibrated at any time.

Dexcoms are approved for 7 days of wear but I usually get about 10 out of them. Medtronic’s are approved for 3 days but I can comfortably get about 5-6 days. I do NOT recommend wearing your CGM for more than they are approved for. I will wear the Dexcoms for a minimum of 7 days and will try to wear the Medtronic for 6. Of course if any site becomes unhealthy I will remove it immediately.


I will post each system’s proprietary graphs for comparison, all the numbers I collect and some standard deviations and averages.

May the best CGM win. Which one do you think will be most accurate? Leave a comment.