Freestyle Libre Failures

Hello all,

I’ve created this topic to share my experience with two Abbott Labs Freestyle Libre CGM devices and their subsequent failures. Last Summer my doctor suggested we try a constant glucose monitoring device in an effort to sort out ongoing issues with blood sugar control. The first unit was attached to my arm around the middle of July and worm for the recommended duration. Upon returning to my doctors office for the follow up visit I was told the unit had only recorded roughly thirty minutes of data (whether or the not the data was intermittent or consecutive I do not know for certain). My doctor suggested we retry the test and another unity was attached and worn for the two week duration. This device also only recorded roughly thirty minutes of data.

The first device was attached to the side of my arm and removed by myself the morning I was to take it back to the office (something I would later regret). The second was attached to the back side of my arm and then covered with an additional layer of tape as a measure against the unit shifting or water causing issues. The second unit was removed by a nurse, tape intact, and the needle came out of my arm straight with no visible signs that anything was out of place.

The failure of both devices in a similar fashion created a great deal of tension and a loss of trust between myself and my physician. He even went as fair as using the word “tampering”.

I’m reaching out to anyone here in an effort to figure out what the issue could be that could cause two failures in a row and each time the device only recording a half hour of data?

In both instances I exercised vigorously directly after the device was installed on my arm as I biked to my doctors office and then rode very hard on the way home. I also had regular strenuous exercise with excessive sweating while wearing both units. In addition I sleep on the side the device was attached and tend to shift around a great deal at night.

That being said the tape that holds the unit on was still holding strong and upon removal each unity showed no signs that anything was amiss with the needle.

This combined with other issues I’ve had with my doctor caused him to discharge me on my last visit. I would have been fine with this as it was clearly time to go in a new direction but after reading the doctors notes for the final visit I found things like “I’m concerned about the patients motivations” and “there is a lack of trust between physician and patient”.

Not to get too fair off the topic (sensor failure in the Freestyle Libre) but this lack of trust did exist but not in the fashion implied in my doctors notes. For the duration of my time as a patient he had repeatedly told me that I was taking far too little Lantus and that my use of Humilog was covering for my base insulin even though I had fasting periods with very stable blood sugars on a 14 unit Lantus dose that often exceeded 12 hours. My doctor at times had suggested I should be taking upwards of 28 units - this based on a formula that he claims hasn’t varied from any of his other patients and had been very effective. Using the formula on the Lantus website shows my dose is right on track.

In addition my doctor referenced that I claimed my sugar would rise without eating in my discharge letter. I did. Everyday AFTER I wake up, whether I eat or not, my sugar will spike. Whats worse is that it does so in varying amounts. One day 3 units of Humalog will cover the spike, others it takes 6 units. He does not believe this occurs even though there are many people on the internet who describe the same thing and a few that claim it’s merely the dawn phenomenon (something not always associated with morning blood sugars it seems).

These things have produced some heated visits and I would have been fine if the final write up had merely said something like “I and the patient are parting ways over a disagreement in the direction his treatment should take”. Something neutral.

So the point I guess is that I wore two sensors for a month, both failed, and I am accused of tampering with the devices and discharged with a write up that not so subtly implies I am a liar and untrustworthy. I can’t live with this. The disease has been frustrating beyond belief for the last decade and now I catch #$#@ for doing as I am instructed by my doctor.

Does anyone else have info about sensor failures and as what rate they occur? Or any idea how a sensor could fail after thirty minutes or so? As I stated earlier, my removing the first sensor (on the day I was to take it back to my doctor) combined with its failure started some of this but the second sensor was removed by my doctors nurse with both layers of tape intact.

It makes no sense why (or how) anyone would sabotage a sensor when that person willingly brings in their meter with months of blood sugars.

I guess I’m hoping that if I can find information that sensors do fail or find the reason why I will at least feel some vindication. Perhaps I can appeal to my doctors better nature and see if he will reconsider and rewrite my discharge letter as well.

I hope someone can help and I thank you all for enduring my story.

  • Mike
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It sounds like you were using the Freestyle Libre Pro which doesn’t give you any data until you see your Dr. The only thing I can think of is that there was a malfunction in the batch that your Dr.s office received. I’ve had the Freestyle Libre for a month and a half and had no problems with it but I am careful not to sleep on it (BTW sleeping on it deosn’t break it it just makes the readings inaccurate). Although, from what the insert in my Libre packages says sweating could be an issue but I don’t know if that is because sweating could make it come off or if sweat interferes with the sensor.

As for your Dr. he is out of line and unfortunately there isn’t much you can do about changing the things he wrote in your file except complain to his superiors as he is unlikely to change his opinion. I had something similar happen to me with a Dr. that I only saw once when I had been having some trouble with my diabetes and she ended up writing something that was inappropriate considering she had only seen me for about 15 minutes before making a strong judgement.

Dawn phenomenon is real and very hard to get rid of, I’m dealing with this right now myself. I find if my BG’s are below 100 when I wake up then the rise is much less problematic. What a lot of people do on MDI’s is take a shot of long acting insulin about six hours before the dawn phenomenon starts. On pumps you have to set your pump to increase your basal rate during the early morning hours.

If I were you I would just forget about that horrible, stick in the mud Dr. and move on with my life. This disease is hard enough without dwelling on what unsupportive medical professionals say about you and he didn’t say anything that will damage your relationship with a decent Dr. I had a Dr. tell my mom when I was 11 that she was feeding me too much and that’s why my BG’s were high. When we went to a different Dr. she realized that my insulin dose hadn’t been changed in a year and I was on half the insulin someone my weight should have been. A good Dr. can make all the difference in your well being.

Sorry for the long response but you had a lot of points I wanted to cover.


Thank you, Firenza.

I know you’re right about letting it go but I’m not sure I can. Like some of the history you shared about what you and your mom went through with doctors I have a litany of experiences that have piled up over the decades with the disease.

My resentment is at an all time high I think. I’m so tired of having to go see these fools every few months to get prescriptions only to have them dismiss the issue you want to address and tell you to return in a few months.

The doctor that discharged me had been my doctor for a decade. As long as I ignored his requests for me to take a dose of Lantus that would likely harm me or put me in the hospital we had no issues (and he was also little help). The last few visits though I wouldn’t back down and challenged him every time and this, combined with the device failures, was the result.

I’m sorry we all have these similar horrible stories with doctors and I don’t think I realized it until this event how much this truly bothers me. I’ve had this disease for over three decades now (diagnosed as a child) and every time I read about others having similar issues with doctors such as yours and many others it brings up a great deal of sadness and anger. knowing that it’s more than me isn’t a relief; it makes me angry.

I’m going to try and not get carried away but I think I will dig a bit more to burn off some energy. Thanks again, you were of great help. :slight_smile:


I wanted to add that I just checked the notes pertaining to the data that was downloaded from the sensor and it is non-consecutive readings over many days. The first sensor only captured 45 readings and the second sensor captured 145 readings.

Anyone have any thoughts? The device worked on and off for the duration it was on.

I think I am going to try and make contact with the Abbott rep that works out of my doctors office to inquire a bit further. I’ll try and report back if anyone else is curious.

I would seriously question the competence of any Doctor who calls themself an Endocrinologist who refuses to accept this. Of course it is real. Similar to many other aspects of Diabetes, I am sure this neither impacts everybody nor hits everybody to the same degree nor responds to the exact same treatment by everybody.

For some people, this seems to be Dawn Phenomenon where the BG rises at a particular point in the morning. For some people, this is Feet on the Floor where the BG rises when they wake up and start moving.

I think formulas are great when you are starting out. But once you have established record of how much to dose, it makes no sense to throw it all away and go back to a generic formula unless your BG are totally out of whack and you intentionally want to hit the Master Reset Button.

If it was me, I would agree 100% with this. I would not trust that Doc either.

Although we use the Dexcom G5, I would argue that any type of cgm which provides you (the person actually wearing it) with immediate information is great. Whether it is the Dexcom, the Libre or the Senseonics (expected to be approved for US soon - already approved in Europe). I would find little benefit to one of the devices which only provides info to the Doc however. Providing this data to YOU, the person wearing it, lets you fine tune your dosing to a degree which otherwise would require (IMHO) much more work and effort. But nothing is magical. Some people certainly have problems with the cgms and there are many threads on those topics in these forums. For most people, they seem to work fine. But not everybody. My suggestion is to not give up on the cgm - although maybe give up on the “Pro” version. Try again but with one of the versions where YOU can see the numbers. And then if there is a problem with the cgm, you will find out MUCH sooner and come back here and many people would be willing to provide a slew of suggestions.


I think you are correct and I should have sought out another doctor years ago, Tim. The thing is every doctor I’ve seen over the last few years, be it a general physician or a psychiatrist who happened to be a diabetic, has insisted I should be taking more Lantus. I’ve run fast after fast and proved that the dose was correct (and the fasts were long enough that any residual fast acting insulin was long out of my system) but it made little or no difference. They only hear what they want to hear. I became used to the idea that I was on my own and my doctor was for prescriptions only.

In regards to the dawn phenomenon, mine starts about an hour after getting up (the time I awake makes no difference) and generally last a few hours. I suspect that the amount of carbs I may have eaten the previously day may have a role in how bad it is as well. It seems like the more energy the kidneys and liver have to release and the longer the fast the worse it is.

I had read on another forum an interesting explanation where a poster had stated this may be something that goes back to cavemen times. The caveman would start each day with no food on hand but still needed energy to make a kill to survive. The body would release energy when the caveman awoke each day to help with the hunt and ensure survival. Not sure if it’s valid but it sure makes a lot of sense. :slight_smile:

I haven’t given up on the devices either. This was just an unfortunate introduction to CGM… :slight_smile: On my last visit my doctor showed me a different device in which you waved a reader over the sensor whenever you wanted for a reading and I have to admit it was fantastic. I’m certainly not opposed to such things but I haven’t kept up with some of the advancements. The idea of not pricking my finger is a pleasant thought and I will explore some options with my next doctor for sure. Thanks much for the feedback.

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Might be a whole different ballgame since it is Libre Pro…?

The reader that you wave over the sensor is the normal Freestyle Libre which just came on the market in the US but has been available in Europe for a few years.

The dawn phenomenon is actually caused by your body trying to clean out the stuff it feels you don’t need. For instance; your kidneys clean out any leftover insulin that is in your blood in the morning. In a non-diabetic this isn’t a problem because you would just make more. Also your liver gets rid of excess glucose in the morning as well so for us diabetics it is a double whammy of not enough insulin and to much glucose running around.


Laura, I am not familiar with either unit to be honest but I seem to remember Freestyle Libre being thrown around at my doctors office when it was attached. This would have been early July of last year. The thing is while researching I found a press release from September of last year that talks about the FDA clearing the Freestyle Libre for use. So now I am wondering if the Libre was being used back then? All I recall is a white disk type device that was attached and then the nurse used another device to make sure it was recording data initially.

I’ve gone back and looked at my records online that are essentially the Glooko report from each unit. The first unit was attached from July 5th to July 18th. The first reading on the graph doesn’t appear until July 12th and their are only 44 readings total spread out until July 18th.

The second device showed readings the entire duration the device was on but their were only 144 readings total.

The weird bit, and I hope this doesn’t distract from what I’ve said above, is that my doctor characterized the first bit of data as, and I paraphrase, “30 minutes of data”. The second was characterized as “two hours worth of data” in other notes. It bugs the hell out of me that he used the word “tampering” in our last visit as the graphs from both tests show intermittent readings with gaps across most days?

My mistake of removing the first unit on the day I was to return it to the office seemed to fuel some of his suspicion but the device recorded reading the night before I was to bring it back which proves it was still on my arm.

To recall what I said earlier I exercised fairly heavily which exposed each device to a fair amount of sweat since it was mid-Summer. I also slept on it and I roll around a lot when I sleep. These seem like more suitable culprits in light of the data in the graphs I would think?

Thank you for the additional information. Am I at least correct in my belief that the dawn phenomenon doesn’t always take place while you sleep? Mine starts about an hour after I am up and generally lasts for about 3 hours (I believe)?

It is confusing when Manufacturers give different versions of a product very similar names. I am sure some Marketing person somewhere believes it makes sense. I think it just creates confusion. Anyway.

The FreeStyle Libre Pro has a 14 day sensor that is put on by a Doctor. The person wearing it does NOT have access to the cgm data. The doctor then downloads the data after the fact. As you mention, this was approved in the US back in September of 2016.

The Freestyle Libre has a 10 day sensor that is put on by the individual at home. You have access to the cgm whenever you want by waving a device (reader) over the sensor. This was recently approved in the US in September of 2017.

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I’ve checked the doctors notes online through the portal and it was definitely some version of the Libra - this was in July of 2017 though?

Edit : Just saw Tim’s post so it had to have been the Libra Pro if it makes a difference.

@Laura_S : Why would it be a different ballgame if it is the Libra Pro?

Absolutely. Like anything else it varies by individual metabolism (YDMV), and most of what I’ve read indicates it can persist for a couple of hours into the morning after you get up. My personal experience with it is that mine has gradually gotten worse over the years, so metabolic changes with age can be a factor too.

And, to reemphasize what @Tim35 said, if your “doctor” is so ill-informed as to question whether DP is actually a thing, he/she has absolutely no business treating anyone with T1. Like finding out out your car mechanic is unfamiliar with the concept of tire pressure.


Thank you, DrBB (and everyone else as well)! I think Tim is correct about moving on but I’m having a hard time doing that. I’ve been reading the office notes from my visits over the last few years and there is a great deal of mischaracterization. I’m certainly not perfect and some of the negative things are fair but a good chunk is very hard to swallow knowing that there was such a large gap in what each of us thought was the issues at hand and what the data actual represented. This whole deal just brought back every time I was dismissed by a doctor or looked down upon. It’s going to hard moving forward with another doctor with this body of incorrect info in the notes. I’m not sure what I’m going to do or how to approach moving forward I guess. Thanks again to everyone who offered info and advice and I most certainly welcome more if anyone wants to chime in. :slight_smile:

My suggestion for moving on.
IMHO it is more difficult emotionally right after leaving your old Doc but before you have started a new relationship with a new Doc.

The quicker you get into a new relationship with a new Doc, the quicker you can put the old Doc behind you.

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Definitely two separate units (Pro being doctor’s version.) I only know my CDE refused to use it in her office, but now she promotes and uses the home version herself. Best wishes!

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One suggestion before you leave the old doc, might be to ask for RX for the Libre reader and sensor, not the PRO version. I just did a trial on one. You would see the BG and trends each time you use the Reader to wand over the Sensor. And you can log additional info to the Reader. It would give you much better visibility to your BG and possible DP over 10 days.

During my trial, the Libre was usually very close to meter BG readings.

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Hi MM1, I would but I’ve already been discharged! I am planning on inquiring with my next doctor about the Libre and other options if I can get to the bottom of why the previous two failed. Even if I can’t determine the reason I’ll still likely try again soon with a similar device. I’ve been going old school with my control since I was a kid and based on what some have said here and a little exploration about new products I’m ready to move into the modern age in regards to my control regime. Thanks for the info!

Wow, I’ve never heard of being discharged! If I move or simply decide to choose a different doctor, I just do so. Was this an Endo or primary care Dr ? If you still have a primary, who treats T2s, they may be willing to RX Libre and also have experience with it.
Good luck.