Continuous Glucose Monitoring

I would like to use these tools in my medical practice for diabetics. Does anyone have experience with any products? I would like to lend such a device out to patients. So I need a technology that works with multiple smart devices and works with Android or iOS.

I believe the Dexcom G5 system is the only CGM that integrates with Android/iOS.

1 Like

Hi Dave, I am using Freestyle Libre (collects data via a dedicated device, not smartphone) yet its cheap and reliable. Please contact me for details!
Katarzyna Wac (UNIGE & KU)

Thanks Katrin. Cheap is good. I see the Freestyle Libre is not approved in the US. How much does it cost in Europe? How can you get the data out of it?

Dear Dave, Freestyle just got approved last week by FDA. in Europe is ~50EUR/sensor and ~60EUR/reader.
So far i keep collecting data and have reports in PDF but i am looking into contacting R&D for a project where i can get the raw data.
Let me know if it helps
take care,

Hi Kate,

Will you say a bit more about how you are working with the data? Do I understand correctly that you currently can only see the data on the display and in a PDF?

I am currently using this device, Freestyle Libre, to gain insight in my glucose levels. There is a possibility to export your data in a txt format from the desktop app (free to use). I copy/paste this in a Google Spreadsheet. The export shows date/time and sugar level in a 15 minute interval.


Thank you Steven for that report. I’m very interested in the Freestyle Libre, am going to ask my physician for a prescription at the next visit. Too bad that you need to copy and paste to get the data but at least it’s possible. There is a somewhat detailed and inconclusive conversation about calibration and sensor quality here:

@Agaricus I am currently using/testing the Freestyle Libre (on day 3) and I am experiencing a similar issue with accuracy. My readings on the sensor are significantly higher (25-35mg/dL?!) than my fingerstick meter! I will give it another day before switching it out for another sensor.

Many people are doing the “NightScout hack” to grab 1-minute interval data from the sensor (instead of 15 minutes readings) using a Sony smartwatch that polls the sensor via NFC, and can transmit the data to an Android device, which then uploads to a server. Full tutorial here.

1 Like

I am aware of two new products, neither available yet:




Recent article on this topic in Time Magazine here.


Dear Dave,

I am experimenting with time restricted feeding and am want to include CGM into my experiment. Which of the parameters of CGM make sense for a prediabetic person?

my review of PUBMED articles on this topic points to these --“average sensor glucose, peak, and minimum sensor glucose, area under the curve (AUC), SD, percent time spent greater than 120 mg/dL, percent time spent at 140 mg/dL or greater, percent time spent at 200 mg/dL or greater, and number of excursions greater than 140 mg/dL and greater than 200 mg/dL”

love to hear your thoughts on this topic!


Hi Amith,
Great question and I do not know what is best to monitor. I do however suggest this
To reverse prediabetes I don’t think you need to monitor much. Simply switch to a whole food plant based diet (which is high in fiber, beans, veggies) and add some interval training. This diet and exercise really treats the root of insulin resistance which is intramyocellular lipid. The nice thing is you don’t need to go hungry or count calories or carbs etc. So long as you fill up on such healthy, low calorie dense foods, it is hard to remain prediabetic.
Best of luck

I like Dave’s response regarding diet and exercise. But, I’d like to add my observations regarding the use of finger-prick glucose monitoring to put that in the record, perhaps for other conversations.

I found that if I apply two test strips (they are not cheap) to one drop of blood, there is no repeatability: one says 126 and the next (same blood) says 145. I’ve been told that to measure glucose response with any degree of confidence, you need to take several (undefined) readings and average them.

My thought is that, at, say, an average of $1US per reading, and taking, say, half dozen readings per session to gather before and after response data, not to forget finger pain, that’s getting expensive in terms of carrying out many repeated experiments.

That drives me in the direction of continuous, or, I think in the case of some monitors, “flash” monitoring.

I do not see accuracy in terms of the relation between monitor readings and those taken by a lab as nearly an important issue as that of the shape of the curve which reflects glucose response.

Those are my thoughts and experiences thus far. I’m looking forward to deeper insights through these conversations.


I had a good experience using the a FreeStyle Libre CGM. I bought it through eBay internationally so my firmware was running in Italian. It definitely helped me dial in my diet (ketogenic), exercise, sleep and fasting. I used a free third party utility called diasend to pull the data from the meter and it also provided useful ready made graphs and tables. I found the glucose numbers to be quite accurate compared to finger pricking. The dawn effect was also clearly observable each morning. My initial thought after two weeks of CGM was why aren’t we scrambling to get these in the hands of every diabetic.

I’m looking forward to trying the other models Dexcom G5, Sano, Glucowise and now the Freestyle Libre Pro available in the US.

1 Like

What is the situation like currently? How hard do diabetic patients usually need to push to get a cgm?

Good question. My understanding is that type-1 diabetics are covered for CGMs through their medical insurance. However, my neighbor who has been hospitalized multiple times was not at all aware of CGMs nor was his doctor so it seems there is a need for education for both doctors and patients around CGMs that needs to happen first.

1 Like

How far can we push this conversation? Would it be a subject change to start talking about some way of sharing results? Sure, that’s fundamentally anecdotal, but then, there are websites like PatientsLikeMe that perform what I call “anecdotal epidemiology” on volunteered patient data. What I’d like to see is some way to “standardize” (whatever that means) reporting GCM readings against, say, meal, time, exercise, etc. Does this portal provide a mechanism for sharing pt reports?

Hi Jack, That question is certainly welcome, but the reply might be frustratingly ambiguous. The answer is “sort of.” It’s not uncommon to publish self-collected data here, and in some cases people have worked with data provided by others. Aggregation is a different and highly unlikely path for us to go here on the QS Forum, as there are both technical and social challenges that go quite deep. However, if you look into the Nightscout project you will find some extremely knowledgable people working with CGM data to manage type 1 diabetes. While not a direct “solution” to what you are asking, this is a good direction to look in for contact with true CGM experts.

Nightscout is fun. As a bonus, if you read it via third party software you can get minute by minute BG data via the Libre.

Oh my. Mine is scheduled to arrive this week!