Dexcom & Data Privacy

This post was inspired by this comment showing an interesting pro-data-privacy image with the message “My Disease, My Data”.

Dexcom makes a great product, at least through G6 (don’t know about G7 yet), but their privacy policy is totally one-sided in their favor. In particular, they can do whatever they want with my data, including selling or sharing it with others.

My only way to vote, so to speak, is to give them as little data as possible. My Endo likes to see my previous 14 days of CGM data before each appointment, and I have given up and upload and share just those 14 days with her office. I would like to make more use of Clarity reporting, but I am not comfortable uploading all my data to Dexcom.

So I use the receiver, because the app on Smartphones automatically uploads CGM data to Dexcom’s servers. But I use the Dexcom app on an extra mobile device (iPod Touch) with internet turned off, allowing me to see more reporting without it being uploaded to Dexcom. But I am missing the more extensive reporting available using Clarity, if I were comfortable uploading all my data to Dexcom’s cloud.

As usual, the legal system trails new technology. I hope privacy laws in the diabetic world eventually catch up. I would be happy to share all my data with Dexcom if I could be sure they would not take ownership of it and share it with others.


I myself was surprised that HIPAA protections are in no way enforceable on Dexcom or other CGM companies.

While I use Clarity (uploading every week or so, and again right before an endo appointment), I note that:

1: I didn’t know there was some sort of date restriction like “upload only last 14 days” that was possible.

2: if I didn’t upload Clarity that my endos office can still read my receiver history in office, although they are miffed if they have to do it. I don’t know if HIPAA protection somehow applies when they do the load into “their office Clarity” or not.

3: I think Xdrip and other apps can provide standalone reports (not uploaded to the internet) similar to (but not identical to) Clarity. I used Xdrip when my Dexcom receiver was broken and didn’t particularly like it.

1 Like

As far as I know, you are right – in order to give my Endo the 14 days worth of data, I need to upload all data from my device (in this case, my receiver) into my Clarity account. I then share the 14 days with my Endo, but Dexcom now has all data that was uploaded. But my point is that since I don’t regularly upload to Dexcom, they don’t get all my data, only what was in my receiver at that time.

I have not looked into data protection when the doctor’s office does the upload, but I suspect Dexcom has just as much access and ownership as it does when we do the uploads. But I don’t know that.

I thought about using 3rd party reporting. I have followed what they have been doing, but so far prefer to stick with straight-forward methods. I am not interested in replacing the receiver’s firmware, for example. Still, this is probably a good time to check in again and see. My career was in IT and I’m willing to jump through hoops if it makes sense.

1 Like

I use xdrip instead of the Dexcom app to control and interface with my Dexcom G6. One of the drawbacks of xdrip is that Dexcom does not allow Clarity access, so I am unable to upload data to Clarity. But because of this, I upload data to instead. I do not even have a clarity account, though I have been using G6 for three years. Tidepool allows anonymous data collection, and summaries similar to that provided by clarity. You control all your data on Tidepool, and choose who if anyone has access to it. My endo is perfectly happy to use tidepool instead of clarity.


I see things slightly differently and may be wrong in my perspective. What they may be doing with my data doesn’t expose me to any harm that I can think of (it’s not personally identifiable) but masses of data may well assist with machine learning and refining of algorithms, which may benefit me or others who have diabetes.
Yes, it probably benefits the company’s bottom line as well.
So that’s why I’m actually ok with it.


I really agree. My endo is really nice. I have great control so I never get anything really said about it. But you can’t not share the data with the doctor if you are hooked up to clarity, when it’s easiest for the doctor and she’s used to viewing the data that way. I want her cooperation, not to set up a possible argument. I kind of miss the old days when my meter wouldn’t even download data. I used to just write down numbers for a couple of weeks and then when I switched to Libre I printed a couple of weeks and took it in. Clarity obviously supplies more data to the doctor which they have to like a lot more.

But I really feel like I am a kid having to report to someone else or that someone else knows every nuance of my BG levels 24/7. I really don’t like that feeling of someone always able to look over my shoulder. It’s annoying to know if I trended low it’s in stone, if Dexcom is off when it starts and skews my numbers. The fact that someone else gets to judge what I decide to do.

It’s either all or nothing with Clarity and the sharing with the doctor. I’m not sure if I was allowed to just share 2 weeks I would easily change that with the doctor. But at least it would be easier to set a new perimeter if I started with a new doctor. I personally really hate the 24/7 sharing and the constant “reporting” to the doctor…


Since I don’t use a pump, I haven’t showed records to anyone since I was a child. I probably kept records when I was pregnant, but I can’t remember. I was testing my blood by then, but only remember my physicians looking at my Alc.

If I change doctors I suppose I might have to show them my Clarity reports, but I doubt at my age that they will try to tell me what to do. It would be different if I had ever had trouble controlling my diabetes or if I was using a pump.

I don’t really care if Dexcom uses my records. If someone explains to me why I should be upset, I might change my mind.


I feel strongly that the more information is shared, the more we all benefit. After all, we are all here to learn and share by participating in this forum. Of course, lurkers always want to gain information without contributing, which happens in all venues of life. Ask any large eCommerce company, and they will tell you that the people that most desperately want to read slews of positive reviews on a product before purchasing tend to be the same customers that are the most reluctant to leave an honest review for the products they purchase.

Over the decades, I have found that the more I share, the more I get back in return exponentially. This forum is a prime example. Although very far from perfect, Dexcom has helped me improve my blood glucose management. I am thankful that they are welcome to use my data, which helps them improve their product, help others, and even monetize my data if it helps build their bottom line. They deserve it.


My understanding is that the problem isn’t with Dexcom HAVING the data, but rather them trying to take proprietary control of it.

It’s a question of legalities and what we’re permitted to do with our diabetes tech. Generally, if you own something, you’re allowed to do whatever you want with it. Hence, Dexcom can’t legally stop us from restarting sensors or putting new batteries in transmitters, so they have to try and just make it more difficult for us to do those things. And they’re getting really good at that! But by claiming ownership of the data itself, it’s one more aggressive step forward in how we use and view our own data. It’s meant to stop 3rd party software from accessing the data. It could be another hurdle against Xdrip, Nightscout, Tidepool, Happy Bob, DIY Looping apps, etc… (Those are just the ones I’ve used off the top of my head, but I know the list is much longer.)
Maybe even the apps you use to put your BG on your watchface.

I simply don’t want legalities in the way of how I manage my diabetes.


I completely agree that society as a whole, and the legal system in particular, haven’t spent much time or energy contemplating the issue of vast databases that can generate medical profiles, consumer purchase profiles, financial profiles…the list goes on. I’ll skip the philosophical discussion; that deserves its own thread, I think. So no argument from me.

From a more practical perspective, I use a Medtronic pump and CGM, and their privacy policy has this interesting tidbit: ‘You may request an “accounting of disclosures,” i.e., a list of the times Medtronic shared your PHI and reason for sharing your PHI with other persons or organizations within the past six (6) years.’ I think I’ll go find out how to actually do that. It will be very interesting to see who else knows what Medtronic knows about me.


I got confused. I thought this was a privacy policy of Dexcom’s, but it sounds like some separate consent they’re asking of their customers. Is there a link?

My point isn’t to put Dexcom down; rather I’d like to know if Medtronic slipped a similar thing into one of the dozens of consent forms I blithely agreed to over the years. You might be surprised at how similar the language is in their respective privacy policies…

I guess another way to consider it is that it’s a “deal with the devil”. (Not in a religious sense).

Maybe the could come up with another plan, such as “You can have your Dexcom and do what you want with it for X dollars. Or if you share your data, and use the device for the number of days we’ve authorized it, etc, it’s Y dollars”

But the company only makes glucose monitors if they can make a profit. If we all figure a way to weasel out of paying for what their engineers and researchers have designed, they will have to shut down. That won’t help any of us!

I think it’s unlikely that any doctor these days has time or energy to pull and review a patient’s CGM reports other than for an appointment.

1 Like

@machiya I know she only does it for an appointment. But she views 14, 30 days and the 90 day data when I do see her. I see her about every 5 months.

But for instance, once my Dexcom was reading low. I decided to ride it out to see if it would adjust itself. I have no problem with staying 80-90 which I did finger sticks to check, but my Dexcom was saying I was in the 60’s. After about 6 hours I realized, oh sh___ it’s going to read as too low on my reports for 6 hours which is going to influence my TIR of “lows”. So I ended up calibrating it.

If I had ended up with 12 hours of it reading low, I have a feeling she would say something. Whether she actually would or not, I have no idea. But it’s that feeling of answering to someone else that is very annoying to me. I want to reiterate I have no issues with her, she is extremely nice and well liked.

For reference, I use a Dexcom G6 and allow my doctor’s office access to my data. A few thoughts on data privacy.

  • As some have mentioned, deidentified data, scrubbed of personal information, can be useful in understanding, particularly at scale. The concern is not so much properly handled data, but when the information is then used for other purposes, in this case, marketing. Right now, we do not know how our information is being used.

  • HIPPA, when enacted, was partially driven by the concern that our medical data could be used against us, as in hiring or when purchasing insurance. Even with HIPPA, it still can. My sense, although I might be giving technology more credit than is due, they do not need me to explicitly say I have Type 1 diabetes. It can guess that.

  • Considering the state of the US, with its level of inequality and plutocracy, the ability to make money trumps ethics and our welfare. Granted, many politicians do care, so there are movements forward in terms of human welfare, but it is slow, and often fleeting.

  • Giving us control over our data is often a smokescreen. It mollifies those that bother to lock down their privacy settings, while most others are either unsavvy, unconcerned, or unaware, so the tracking just continues.

  • In truth, and it might sound contradictory, I have little concern about tracking. I lock down my accounts to avoid identity theft, using distinct passwords based on an algorithm - I do not use a password manager - and using two-factor authentication where the risk of loss is high, e.g., major social accounts, work, email, banking, government, etc.

  • This might sound absurd, but I think targeted marketing is of little value on me. I ignore almost any ad, and anything that does catch my eye would never lead me to purchase a particular product. At scale, it works. Someone is affected by the advertising, but it is unlikely to be me, although I imagine softer forms of marketing, related to impressions of a company, might be effective.

  • I use the internet in some ways for self-promotion, mostly for my career, so my social accounts show art and social events, my LinkedIn profile is fully filled, and I regularly re-post articles to maintain traction.

1 Like

Thanks everyone for the comments about Dexcom and data privacy. Lots of interesting points of view.

Several of you have mentioned you are not worried about Dexcom’s data privacy practices, do not think those cause any harm to patients and in fact may help improve the products for us.

I mostly don’t disagree. In particular, if I had to choose between not using Dexcom products or using them knowing Dexcom sends my data to third parties, I would choose what’s more healthy for me, not what best fits my data privacy beliefs.

We pretty much all have to live with most companies collecting our web browsing data, including, as Dexcom’s Privacy Policy states: “your online browsing behavior such as the sites you visit before and after visiting our websites…”.

My concern is mainly about what Dexcom calls “Health and Use Data” which includes blood glucose readings you may upload for Clarity reporting.

Their Privacy Policy states: “Dexcom collects personal information categories including identifiers, inferences, and usage data.” Note this includes your BG readings. “Dexcom discloses this information to third parties…”. Note they do not mention anonymizing or removing your identification info, though importantly, they state they comply with European GDPR regulations. They state they share this data for what I’d call marketing reasons, but they do not expressly limit the reasons for disclosing to third parties. They also state “Dexcom does not sell your information for money, but we do disclose your information to certain third parties that provide valuable services to us, such as analytics and advertising services, which may be considered a “sale” under the CCPA.”

I can mostly live with all that. I just wish they would not share “usage data” like my BG readings with third parties. I believe the health industry, including Dexcom, needs to lock down this data and not share it without patients’ explicit consent. Right now, they just do what they want with it and mention it in a Privacy Policy.


To clarify, as I was one of the ones posting, there are lots of issues of sharing.

The problem is that Dexcom (and Abbott and Senseonics) don’t let the end-users have direct, real-time, on device (on our phones) access to our own data! We have to rely on 4-hour time-delay from apps like Apple Health.

They could easily allow instant access as they allow the partners who pay a lot of money for access. It’s about the API. It’s an easy fix.

And only those who are more involved in apps using DIY solutions or their own analysis or are developing (innovating) apps for better closed loop systems would need this.

Bottom line … why can’t we have that access? It really is our own data. We sign away our rights to let them sell access. It should be automatic that we have access, if we want it.


Hi, I am the parent of a, now, adult person who has lived +30 years with T1DM. We noticed at least 20 years ago that in order to OBTAIN life-saving T1DM supplies from the big corporations in the US that the INSURANCE industry had many many loopholes regarding privacy. HIPPA is a joke for us. The folks who have the hardest time obtaining data are the MDs (or other “providers,” and those who have DM … It’s really just a ruse. Privacy of date does not exist. … When the insurance corporations, including Medicare, out-source all their work to overseas, is ANYone paying attention to HIPPA ?


Agree. Whether it is T1DM or other DM, OR any other ICD-10 coded disease there is NO privacy. Period.

1 Like

I do IT security for a living so this topic is something I’ve given a lot of thought to. My first CGM was an Abbott Freestyle Libre. Abbott drove me nuts by using a Chinese social media company to write their iOS app. I did a packet capture to find out where the app was sending data. Turns out, Amazon S3 in the US. I am currently using the Dexcom G6 because I got tired of the Libre reader blacklisting perfectly good sensors due to a software bug that Abbott refuses to fix.

Dexcom has a privacy page (thanks @Buck for mentioning privacy disclosures)
that has most of the important information written in PR-speak.
The privacy policy page referred to by @Jim10 does contain some CGM specific information.
Thanks to Japan and South Korea the Privacy Policy tells us Dexcom is using the Google cloud for data storage.

Personally I take every opportunity to restrict access to my health data. I am not using a Dexcom CGM so they can sell my data to researchers to make more money when their product is already overpriced by at least two super bowl commercials.

My endo’s office is just as bad. Tenet Health owns the medical group that runs the office. Their website is a shambles, they can’t reliably send their self check in emails and most recently they started using that company that makes you click a box agreeing to let them sell your contact info in order to sign in to Zoom appointments. There is no way I can trust the with the Dexcom Clarity connection to my data. I send them PDF’s of the Clarity reports to limit their access.

Some people stated using alternative apps. If you are using an alternative app because you don’t agree with Dexcom’s data policies it is important to know if the apps keeps your data safe. In the case of xdrip, data is not stored securely on device. Tidepool’s business model is literally to collect heath data and sell it. Everyone has to weigh these tradeoffs for themselves.

Lastly, above someone mistakenly stated HIPAA doesn’t apply to Dexcom. This isn’t correct as evidenced by their Privacy Policy and HHS HIPAA FAQ 490 second paragraph.

1 Like