G6 reading: 124. Finger stick: 132. I didn't believe the finger stick

Caleb does the same - or sometimes forgets that early morning fingerstick. I don’t remember what is advised by Dexcom - is it one a day?

No, I think calibration is entirely optional. I just like the sanity check.

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I was an automotive tech for about 16 years, and for 10 years of that I was on insulin and tested my bg’s w/o using a lancet device. I use to just jab a bare lancet into my fingers which were DIRTY with hard-to remove grease that I could smell on my skin even on Sundays after daily baths and scrubbing with brushes and using a variety of hand cleaners. My fingers had many black spots from the dirt getting embedded into my skin. I didn’t even have a meter then–I used visually-read strips, called chemstrip bG. There was a meter that could be used with those strips, but I didn’t think I needed it and besides, I could cut the strips into 3rds to save money. Unfortunately I never could properly analyze the colors and when I finally got my first LifeScan meter, I realized my bg’s were running far higher than I thought. Nowadays, mechanics wear gloves. That would have been really nice back in “the day”.

Folks who have never used a lancet by itself can’t appreciate how much comfortable it is to poke oneself with a good model of lancet device. The spring retracts the tip so fast that pain is greatly reduced.

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G5= 2x a day
G6= none

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That’s amazing. Not only that none are needed, but how slow and resistant I’ve been to accept that fact.

:slight_smile: I cannot freaking believe how accurate my sensor has been. Today is day 10 and to build up a bit of a stash I’m gonna try a restart. My wife restarted hers (an earlier version of the transmitter) and she was successful. But it was only accurate for about 4.5 more days. Her current G6 is as accurate as her first one. Same lot number and calibration code. My first box of sensors, all same lot number, but 3 different calibration codes.

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I’m glad that you are pleased. :slight_smile:

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I’m glad that I’m pleased, too! :slight_smile: I was not looking forward to the G6 as I’ve stated here and at the various FB groups. :slight_smile: Either Wayne or Garth said,“we fear change!”

Me too. The huge difference to me, though, is not having to do the double calibration after warm up with a new sensor. WIth the G5 I was always having to take that into account: If I start the warm up now what am I going to be in the midst of two hours from now when it yanks my leash—in a meeting, driving, choir performance, yada yada yada. Now I can just start it going and not have to think about it. I didn’t think it was going to be that big of a deal when I was considering the upgrade, but it actually is that big of a deal.

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I was doing quite a few finger sticks when I started G6, but now I’m completely confident letting it do its own thing and making my decisions from the readings. I do test if my symptoms don’t match the G6, but in almost all cases the G6 is right! Case in point - yesterday the G6 showed my BG was tanking and was at 66. Didn’t believe it so checked with my Contour - 60!

I do check frequently if the sensor starts to act whacky - sensor errors, wandering baselines, etc. I sometimes find some whopping errors and usually just change the sensor.

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Welcome to the real world. I can have various results from finger to ginger hand to hand. I brought this on my Endocrinologist attention. In your case the range stayed is well with in range . Look at it this way, would you make any treatment change on this range.

When the second finger stick matched closely to the CGM, that is what I go by.

It can really vary it seems person to person how long you can let the sensor stay on. I was getting about 26 days pretty consistently on my G6 sensors, but the last two have only lasted about 22 days.

I love the stable readings of a good G6 left on. I actually get a little annoyed when I have to replace it!

I have been using the G6 for over a year. I ran it concurrently with a G5 for 6 months.

My observation is some G6 sensors are OK, while others are not. In some cases, the G6 would start out OK, but then have its accuracy faulter — and visa-versa.

After entering a code, the accuracy of some G6 sensors would improve with a calibration every few days.

But I found the best accuracy was when using no code. In that scenario, accuracy seemed better than the G5.

I also learned never to trust a single test strip, unless it read very close to the CGM. About 2% of my test strips give wild readings.


If u do that, does it work like the G5 as far as 2 cals per day? ie, you get a message on the screen reminding u to cal, but it can be put off indefinitely, like the G5?

I’m also very curious how the G6 behaves without code. I’m considering trying restarts without code since I test twice a day after anyways. Not sure if there’s any benefit since I’m already getting great results after restarts. Would be really annoyed if I HAD to do them at specific times, though.

Yes. Without entering the code, the G6 acts exactly like the G5 in regards to calibrations. I tried this approach a while ago and saw no improvement in accuracy and only gained the need to calibrate every 12 hours.

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Yes. Obviously, you need a double calibration after 2hr warm up, and it requests one 12hrs later & every 24hrs after that. But I have postpone later calibrations up to 48hrs. The only hassle is a t:slim pump harasses you to death if you postpone calibrations – it is sure that Control IQ is compromised.


(Please excuse the brevity; sent from phone.)

Hi all… something I didn’t see in this discussion is an essential issue: YOUR BLOOD IS NOT HOMOGENIZED! Here’s a little response I wrote regarding meter differences… it’s not directly on point (because CGMs DO lag BG), but contains some important points.


I often see questions about why someone’s BG (Blood Glucose) meter gives different results than the lab, or another meter, or from two successive drops of blood. There are MANY reasons a meter reading varies… and it is RARELY “meter error” – that is, statistically, the LEAST likely reason. So here’s a primer on BG meter use.

To start – YOUR BLOOD IS NOT HOMOGENIZED, so there is NO REASON to expect your BG level to be identical in two different samples – even two successive drops of blood WILL and DO vary; right off the bat, they may ACTUALLY be up to 10% different.

The glucose in your blood is there for a reason – to FUEL THE CELLS OF YOUR BODY. SO… glucose is CONSTANTLY being “lost” by the blood – as your blood travels through your body, it is “dropping off” glucose molecules to EVERY CELL of your body – and that means that the concentration is constantly changing. As your blood travels through your gut – it “picks up” glucose (from the liver and the digestive tract), then begins losing it until it returns to the gut.

Besides delivering oxygen, nutrients and glucose to your cells – your blood also removes waste products from them (primarily carbon dioxide, but several others as well). This means the composition of your blood is constantly changing in many ways; this also contributes to varying concentrations of glucose (and everything else) in your blood in different areas of your body.

Capillary blood has become the “standard” for blood glucose monitors; it’s easy to obtain, and consistent vis-à-vis the composition of the venous blood used by a lab. The meter itself uses a mathematical algorithm to “convert” the glucose concentration of your capillary sample to what your venous glucose concentration WOULD be if you could test that. BUT… it’s important to know that venous and capillary glucose concentrations differ A LOT – up to 49.6%. This is why you should NEVER “test” your meter against a lab result by using a sample from the venous draw on your meter. Test the capillary blood the meter was designed for.

SO… right off the bat, no two samples of blood are going to be the same. AND… the samples we use on BG meters are TINY – labs use much larger samples in order to get a consistent result. And before testing – they centrifuge the sample, which while not the same as homogenizing it, accomplishes a similar result. Consider this – if you were paddling a canoe across a lake, and you dump a pound of sugar into the lake in the middle – would you expect a measure taken at the shoreline, and one from the rear of the canoe, to be the same? Of course not. The situation in your circulatory system is the same.

Next up is the meter design. Most – NOT ALL – modern meters are designed to allow for “alternate site testing”. This is where you obtain the blood sample from somewhere besides the fingertips. The meter instruction manual will tell you whether or not alternate site testing will work with your meter – and will tell you WHICH alternate sites are best for that meter (typically, these include the palm of the hand, the forearm, the calf, and so on – but follow your meter’s specific instructions). In any event… the meter is still intended for use with CAPILLARY blood – not venous or arterial blood. And most older meters do NOT work with alternate test sites.
The next issue is the variety (and it’s large) of variables that affect BG reading outcomes. Besides the fact that every meter is different, using different algorithms and electrical sensors, there are variables in the strips themselves, and in the environment.

Environmental factors that affect BG readings include temperature, humidity, and altitude, all of which will affect the outcome of each blood test.
The strips themselves are affected by the enzymes used in them that react to the glucose in the blood sample, the well size of the strip (the well is the space in the strip that holds the blood), the age of the strip (the enzymes are affected by age), the conditions the strips were subjected to during production, shipping, and storage both before and during their time on the pharmacy shelves (again, temperature and humidity will affect them), and the oxidation of the strip components.
Next is the blood itself. Each individual’s hematocrit level is different – and all meters assume a fixed hematocrit level. The hematocrit level is the percentage of RBCs (Red Blood Cells) in the blood, by volume. In people with low hematocrit levels (<35%), BG readings will be falsely elevated. There is, of course, the possibility that elevated hematocrit levels may provide false low results – though I’ve only seen confirmatory studies for low hematocrit levels reporting false highs.
Finally, medications in use will affect the enzymes that the strips rely on to “convert” the glucose level to an electrical current that is then “converted” to a BG level. Tylenol (acetaminophen) will cause a false elevation of the BG reading; there are many others as well.

SO… do NOT assume that just because you get two different results, or different results on two different meters, that the meter is “bad”, or in error. The greatest source of error in SMBG (Self-Monitoring of Blood Glucose) is USER ERROR. People performing BG tests make mistakes – a LOT. The next largest source of error is the STRIPS… different batches of strips are produced separately, and are all subject to variable that will affect their accuracy – from the manufacturing process itself, to the conditions in which they are stored, shipped, kept on shelves, and storage in the home of the user. Next comes the individual blood / biochemistry variable, and last comes meter error. That is, of course, just statistics… but it’s the way to go with evaluating “why” a BG reading isn’t what you expected. There are limitations to what meters can do – caused primarily by the fact that they are designed to be “simple” to use, which means they do NOT account for all the variables.

Ultimately, we must rely on our meters – but it is important to understand that they are imperfect machines that provide useful, but variable information that is heavily affected by a LOT of things. Oftentimes, what is more important is the trends they indicate – the raw data is subject to variation from many sources. The blood itself differs by as much as 10%, the meters are only accurate to within 20%, and many environmental factors affect the results. If you suspect meter error – test the meter with the manufacturer’s test fluid.


The short version of that is this: if you want to see how repeateable the results are with your meter, you must test from the same drop of blood! Get a nice BIG drop of blood and test a couple of times. If the readings are very close, or identical, and any random time that you repeat this test, you know your meter has, if nothing else, great repeatablilty. Don’t expect that a drop from each hand is going to test identically., If those tests do, count your blessings. But the next time you try the test, there be far more variation.