Our Dexcom G6 experiences


Actually the opposite. In 10-15 minutes, you look at the CGM to see if that current number more closely matches the fingerstick from 10-15 minutes ago. I’m sure you know that and got confused when typing. :slight_smile:


Tech support told me the thickness (the G6 being the thinner one), the angle, and the length of the sensor are different (not by much) to the G5. I don’t know any of this by independent corroboration–just reporting what I was told.


We don’t do anything that is listed and have very good results starting 12 hours into the session.

  • We start the session immediately after insert although are careful to ensure a minimum of 10 minutes between stop of the previous session and start of the new session. Normally not a problem as the previous session usually ended some time ago before we get around to putting a new sensor in.

  • We will often put a sensor on immediately before bedtime such that the warmup itself is while lying down in bed. This I have found to be super convenient with the G6.

  • We don’t pay any attention to BG rise or fall (other than obviously bolus or carb appropriately but nothing to do with cgm) when starting a session. This also is hugely convenient with the G6 not having to worry about this. IMHO this makes absolutely no difference when running the G6 with factory calibration.

  • Force of the inserter. This point - I can see this making a difference. I will actually pay more attention to the force the inserter is held against the skin and see if it correlates to better or worse sensor sessions as well as better or worse “bleeders”.

I disagree with this. The G6 predictive alert is based on the trend/slope of cgm data values already presented.

Unfortunately it is true that Dexcom has switched to a 30/30 rule for the G6 as opposed to the 20/20 rule for the G4 and G5. That is horribly disappointing to me but is fact as can be read in the Dexcom User Guides. However I disagree that one should only calibrate if outside the 30/30 range but I do understand that is what the User Guide says.


Since I started to use only very light force to hold the inserter against my skin, my sensors have been perfect. At the miracle level I would say.


Thanks for the correction on the algorithm. Whether predictive or not, when the blood sugar is changing quickly, I often observe when a new reading appears, the PRIOR reading changes. It’s a curiosity I found when I was looking at the rate of blood sugar decline when using Afrezza to correct a stubborn high. I look at the point difference between data points as an indication of how much longer the Afrezza will stay active. It’s out of your system really quickly. When the rate of change falls off precipitously, I can then decide if I should use more insulin. If the algorithm is changing a number that occurred in the past, that past number isn’t the algorithms final number.


I also heard the sensor is smaller diameter on the G6 - that came from a Dexcom employee at an exhibit. The CDE didn’t say there were no differences, just that there were no difference that would explain my issue with compression lows.


I’ve not heard anyone, Dexcom or others explain the reason for compression lows on G6 that seem to outnumber those of the G5. I DO get them on the G5 so from my experience over 18 months I say the G5 is hardly immune to the issue either.


Yeah. Another G6 special.
This is most definitely NOT predictive but the reverse.
This is historical graph smoothing.

This is not restricted to rapid BG changes.


I had no idea it did that. I’m not sure that is desirable–ie,re-writing history. Hmmm…How many prior readings can it change? Is that limited to only the previous reading?


I used to get compression lows when started on the Dexcom G5. By changing the placement of the sensor, compression lows are now a thing of the past. I sleep on my sides so when I place the sensor in line between the sternum xiphoid process and the belly button, the transmitter never gets buried in the mattress and therefore no longer have compression lows. There is enough vertical real estate there to be able to insert sensor in a high or low position giving each insertion site a rest for a few weeks.


I usually sleep on the right side, so my sensor is always on my left abdomen/love handle area. But sometimes I turn the other way and invariably the sensor will read too low.


Good question. I never checked. Probably not too much work to figure that out.

Yeah - I was/am on the fence. I would be more enthusiastic if this was listed and described in the User Guide. (Unless I totally missed the chapter on this “feature”.) I am really not a big fan of undocumented features.

If looking at this in the most positive light, the purpose could be to correct mistakes and errors. It is more likely that your BG actually does have a smooth curve. So if the cgm has a blip in the middle of a curve, is it not more likely that the cgm was in error and that data point really should fit the curve? (Trying to explain it in a positive manner.)

But really - I am not sure and am on the fence if I like this “feature” or not. Still I have not decided. It is what it is however.


Ya, so if you stick sensor in the middle it is a win-win. No compression either way you face. Works like a charm.


Xdrip has had to option for smoothing for quite some time.
I didn’t use it at first, but after I started using it with the G5 and completely stopped calibrating, I had GREAT results.

I almost have to believe that Dexcom took notes from Xdrip when they created the code for the G6. This is just purely a guess, but I was going without calibrations on the G5 and Xdrip with almost perfect success for quite some time.


Btw, I have over 3 months now on the G6.
I LOVE the Basal-IQ!
I HATE the 10 day cycle. I cannot wait until they just implement the 14 day cycle with better adhesive.
I got very good at starting each sensor very early every Sunday morning. Don’t eat anything until after the 2 hour warmup. And I had great results. Sunday was rarely a day for me to eat much anyway, so the G5 has a pretty easy time settling in.

The new 10 days really throws me off. I have to either start a new sensor right before bed, or right before I go to work.
Both spell a recipe for disaster for me. So my first day now is NOT FUN.

All that said, I am glad I got the G6.
And I am ecstatic about the Basal-IQ!
Just can’t wait until we get some real control with the highs on the next update.


Did some digging on Dexcom’s signal processing looking through their patent portfolio. The one that best describes signal processing comprises a two-step process. In the first step a series of glucose values are obtained. That series of readings are first smoothed to improve signal to noise and measurement accuracy. In the second step the smoothed curve is used to predict future blood glucose values. Based on what they describe, the smoothing and predictive algorithms are probably quite complex.

So the change we’re seeing between the initially displayed value and the modied value that appears after a subsequent reading is a function of smoothing, not prediction. The value that appears after the next measurement is a more accurate value because the smoothing algorithm has been applied. That’s why the Dexcom manager said to wait for some period after the reading appears and then compare the smoothed (more accurate) value with the finger stick value.

So in a nutshell the smoothing algorithm modifies and makes past measurements more accurate. So it is backward looking. The predictive algorithm is forward looking and based on the smoothed data.

They have several applications on sensors than might give a clue on the differences between the G4/G5 and G6 sensors, but I don’t have enough caffiene in my system to read the legalize. I’m retired now so my days of digging through patents is thankfully behind me!


I woudn’t take the recommendations I received as gospel and necessary for all. The advice was given to help me resolve the specific issues I’m facing. I don’t yet know if any of them will help improve my results. Some of the recommendations may not make sense, but I’m giving Dexcom the benefit of the doubt as they are the manufacturers and likely have knowledge we don’t.


I’d love to see the details of the exact differences in the G5 & G6 sensor wires, to find out if what the dex tech told me is accurate, regarding the differences in physical construction (thickness, angle, length). I’d also like to know if the chemical makeup is any different. OR, is much of the difference in advertised accuracy a result of improved algorithms. It would seem to me that longer wear times that are advertised reflects Dexcom’s confidence that the material in the G6 can work properly longer than the G5, which I infer means a difference in the amount of, or the make-up of the chemicals used in the sensors.


The coating on the sensor is different.


I rarely have gotten a lost signal, but I put it on my arm and save my stomach for my Omnipod. I am glad it’s on my arm as the adhesive is so bad. Their “overpatch” is just as bad. Skin Tac has worked really well although every once in a while I’ve caught a edge and just applied more on. I need to order the remover though as I have a mess to clean off after I take it off. But my arm works best as I also wrap it with an ace bandage before I snorkel as I am paranoid now it will fall off in the ocean! I didn’t worry about it with the Libre as the adhesive wouldn’t deteriorate when gotten wet. It would just pop off easy if hit wrong! Plus if I did lose one, it was a lot cheaper to just put another one on.

But I restart my sensors. I have had no issue doing that. I’ve only been wearing them for 2 months, so haven’t been doing it long term. I don’t know how long they will go for as I had to pull the transmitter off a couple of times for other reasons.