CGM what do you think?


FreeStyle Libre has no alarms, you must swipe first. So I am wondering if this is more useful to type 2 . As a Dexcom ,etc has alarms that will wake you at night. I wonder if eventually the Freestyle libre will have any alarm on it? So I guess it does depend what your needs are in the end. Just some thoughts,just for discussion. Nancy


Actually I cannot call the Freestyle Libre a CGM. I view it as a different way to measure blood sugar. I am not knocking it, the Libre seems like a cool system, but a CGM? It lacks alarms, it requires very near (like a few inches) to be read and it does not supply data unless it is in that near proximity. Yes it is hybrid meter / CGM concept. It just does not seem like a real CGM to me.


There is a device called the Ambrosiasys Blucon that effectively converts Libre into a cgm. It is basically a reader that you tape or strap over the LIbre. It then sends readings at 5 min intervals to a mobile phone, converting Libre into what is effectively cgm with alarms, ability to upload to a follower via Nightscout etc.

Google it.


I’ve noticed some disagreement regarding the semantics of the term, “CGM,” with the introduction of Abbott’s Freestyle Libre to the US.

Some Libre enthusiasts are saying that the Libre is a CGM (continuous glucose monitor) since it does read and store a glucose value every minute. I see the logic of their point.

The critical difference is that the Libre will only display a value when an electronic inquiry is made. The Dexcom CGM, on the other hand, will audibly announce when key glucose thresholds are crossed. It does not need an inquiry and is especially valuable when you’re sleeping.

The Libre flash glucose monitor provides a highly useful tool in a more affordable format. This is a valuable device offering a much needed service to an underserved demographic.

The device that @jjm335 mentions above gives the Libre a voice to announce critical alarms, a nice work-around. I wonder if the Libre + Blucon is still cheaper than a Dexcom CGM.

Pehaps using the terminology of data that is either pushed like Dexcom & Medtronic CGMs or one that only responds when data must be pulled or triggered by an inquiry, like the Libre. That could be shortened to a push-CGM or a pull-CGM. Just a thought.


I think calling it a CGM is a bit of puffery. :slight_smile:


My two cents: I’ve had the libre for 36 hours and the reader stopped functioning.

2 caveats: my libre numbers are a full 15 min behind my bg. And I have found the numbers are erratic if I accidentally sleep on the arm with the sensor.

It’s great for what it does: which is keep me from poking myself so much. And the reader does warn me via a screen if my glucose is low, but why didn’t Abbott attach an alarm to that screen???

If my loved one had diabetes, I wouldn’t give corrections based solely on the libre, which is what the makers themselves say.


I have the Libre as it’s good in a sense that unlike the Dexcom (i have not tryed it) it has ALARMS!!! that would be so annoying in the middle of the night.
I have had the first BG Meter in the early 80’s’s as that was a game changer for me as then the medical community then thought that carbs are the enemy, not sugar. Again Sugar is a carb we know that.
The Libre is a kinda a CGM of sorts as it will show where it’s going, the sensor is easy to use as i just have to know it’s there!!! LOL it’s very comfortable and the Application is again very easy.


But anthill, I’m a bit confused, wouldn’t you want the convenience of ALARMS in the middle of the night that Dexcom gives if your BG drops in the middle of the night?


Remember with the Dexcom alerts. These are easily changeable. Turn them on or off. Set them to whatever value to like. Change the alerting sound.
I have the Dexcom alerts set to go off when I will need to actually take action.

I also change the alerts all the time. If we are cruising along relatively stable within our chosen range then I would set the alerts perhaps at what I consider the high and low end of our range.

On the other hand, if we give a big bolus at nighttime to correct a crazy high then I would bump the low alert up to 100 to get notified when the BG is coming down so I can be alerted and decide if further action is required. At which point, I might bump the low alert down lower depending on what I have decided is appropriate at that moment in time.

Caveat being of course that the Dexcom critical low alert is generally fixed at 55.


I bought my first Libre on ebay a while ago after reading an article back in 2015. As a T2 the big issue for me was understanding my 24/7 BG profile and understanding the role of different foods at spiking my BG and understanding how to blunt the spike. Clearly metformin proved useless at this.

The main issue a T2 has is they have lost the robust first phase insulin release and as a result have lost the ability to get it back into a non-diabetic range asap.

For me it took less than a month to get a pretty good handle on the numbers and as an engineer it became pretty obvious that “Engineer” (and doctor) Bernstein was right and diabetes is really an engineering flow control problem. Stop the spike, get back in range and as Ralph DeFronzo is finding out in his Qatar study there is a pretty good chance of beta cell regeneration with early T2s. This is similar to what Al Mann said of the PWDs in his studies.

I had no use for alarms and taking my cell phone out with the Glimp and touching my arm versus taking my cell phone out and just looking at it is six of one, half dozen of the other to me.


For anyone who doesn’t have insurance the Libre is definitely cheaper at $42 a sensor which lasts 10 days vs Dexcom which is approximately $300 a month, if used as recommended.


While “recommended usage” is certainly fair, putting the “typical usage” alongside would provide for a more balanced comparison.


I got the Libre for Christmas and so far am loving it. It does run about ten to fifteen minutes behind a finger prick but since I expected that it doesn’t bother me, and it has already been helping me catch highs before they’re a problem. Since I can feel my lows I don’t really need an alarm for that although rumor has it that the next generation of the Libre will be a full CGM. The only thing that is an inconvenience on the Libre is the 12 hour start-up time for each new sensor so for those 12 hours you have only finger stick data and that is a pain (literally).


I considered that when I was researching CGM’s and decided that relying on borrowed time would make me pretty nervous as I am paying out of pocket and if the Dexcom sensor went bad before my budget allowed me to buy more I’d be out of luck, whereas the Libre sensor is comparable to a cheaper box of strips.


I’m on my second Libre sensor and so far I’m pretty happy with it. Over the past 50 years or so, I’ve used the yellow urine tape, klunky BS meters and finally much more accurate meters. There were no alarms and readings were sometimes inaccurate. I’ve had my share of really high highs and really low lows. But each step along the way helped me improve. The Libre is another huge step along that pathway.

I don’t consider the Libre sensor a “cheaper box of strips.” I can and do use the sensor in situations where I would be very unlikely to test with a conventional meter. I know that there are certain times when a hypo might occur and I used more strips at those times. But I also know that after I’ve eaten a full meal, I’m unlikely to go low for a few hours. So if I’m at a rehearsal or driving someone home afterward, I usually won’t pull out the strips. With the Libre, I can not only spot the lows coming, I can keep within a tighter range most of the time. So what I can say is that I’ve had fewer lows and have changed my insulin dosing in a way that I couldn’t before. I expect further improvements as I get used to using the Libre.

I get that some diabetics are hypo-unaware or have a child that needs close monitoring. And for them, the Dexcom makes a lot of sense. But I can’t really get into this discussion about what we call a CGM or not. I can’t believe people are walking into their pharmacy and getting a Libre with the expectation that it has alarms for example. I’d like to think that anyone who goes on one of these new devices has either done their own research or had their doctor point out the advantages and limitations of their choice. No one word description will make up for that discussion.

Finally, whatever features the Dexcom or Libre has (or lacks) today, they will be different a year from now. I’d like to celebrate that there are two very helpful choices available now. And that more and improved choices will be available in the near future.


Well said!


They never improved the Glucowatch! LOL!


My cheaper box of strips comment was concerning price not the incredible convenience of taking literally a second to painlessly test my BG, not to mention my Libre says I’m averaging 32 scans per day vs. the 9-11 times a day with finger pricks.


Yes not having to prick your finger for each test is a huge benefit of accurate cgm’s or the Libre system. Once in awhile my CGM isn’t as accurate as usual and then I have to prick my finger a few times over the course of a very short time and it reminds me how annoying it has been since the 1970s for me with regards to pricking my fingers more than a dozen times a day


There is a patent barrier on real time alarms that Libre has not found a way to overcome. All current CGMs will lag regular glucometers because the latter reads blood while the former reads insterstitial fluid. There is an unavoidable lag between the two readings.

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