It’s Libre, Man! In-Depth Review of the Newly Approved Freestyle Libre

/, Thinking Like A Pancreas Blog/It’s Libre, Man! In-Depth Review of the Newly Approved Freestyle Libre

Diabetes educator, Gary Scheiner gives his in-depth review of the newly approved Abbott Freestyle Libre CGM continuous glucose monitor.

Faster than the fastest meter.

More powerful than point-in-time measurements.

Able to leap piles of test strips with a single scan.


Look… on pharmacy shelves (soon).  It’s a meter.  It’s a CGM.  It’s FREESTYLE LIBRE!


Seriously, this is exciting.  Abbott’s Frestyle Libre has finally been approved for sale in the United States.  Why the excitement?  Because it almost eliminates the need for fingerstick blood glucose measurements.  It has features of a CGM (continuous glucose monitor) and a blood glucose meter combined in one device.  And it is simple to use, reasonably accurate, virtually painless, and relatively inexpensive ($60 for the durable receiver/scanner, $40 per sensor; insurance coverage pending).


Super!  How does it work?


An applicator device is placed on the back of the arm.  With one push, a tiny glucose-sensitive filament is inserted just below the skin, with the waterproof transmitter (about the size of two stacked quarters) attached and adhered to the skin.  After a 12-hour warmup period, a signal is sent every minute to a handheld receiver about the size of a small cell phone, and the current glucose level along with a trend arrow and graph of the most recent eight hours of data is displayed.  The sensor/transmitter is replaced every 10 days.  And because of its accuracy, NO fingerstick calibrations are required.



A very similar device has been available in Europe and other parts of the world since 2014.  The hardware is basically the same, but there are a few subtle differences between the US version and the European version.  The European sensors last 14 days each as opposed to 10 with the US version (the sensors cannot be “re-used”), and the warmup period only lasts 1 hour (as opposed to 12).  However, the accuracy of the US version is slightly better (average error of 9.7%, compared to 11%) – likely due to the longer warmup and shorter length of wear.  Also nice to know that the sensors are not affected by acetaminophen.


Everyone at our practice had a chance to try out the European version of Freestyle Libre soon after it launched (it helps to have friendly clients all over the world!).  We were impressed with it from the getgo.  Compared to current CGM systems, it is very easy to insert and use right out of the box.  No training required.  Despite the lack of fingerstick calibrations, the data generally matched up well to our fingerstick meter readings (you didn’t think we would trust it THAT much, did you?). The comfort was also quite good, although the adhesive left a little to be desired.


OK… What’s the Kryptonite?


My pappy once told me that if something sounds too good to be true, it probably is.  While Freestyle Libre combines many of the features of CGM and fingerstick meters, it comes up short in a number of key areas.  Perhaps the most glaring weakness is the lack of alarms/alerts for pending high and low glucose levels.  Because the user has to physically “scan” the receiver just over the transmitter in order to generate any data, the device does not track things constantly the way a Dexcom or Medtronic sensor does.  The only way to know if you’re low or heading low is to do a scan.  With so many people lacking early warning symptoms for low blood glucose, traditional CGMs are relied upon heavily for avoidance of significant hypoglycemia.  Libre may help users cut down on the frequency and severity of lows, but only if the user scans the sensor every 5-10 minutes, including through the night.  And that’s just not about to happen.


Libre also lacks the ability to transmit data to a cell phone or to “share” the data electronically with loved ones and caregivers.  This will likely change over the next several years, but for the time being, the only person who can see what’s going on is the one who is scanning the sensor.


And how does Libre stack up to our trusty, dusty blood glucose meters?  Sure, Libre has been approved as a replacement for fingersticks, but does that mean it should be?  Remember, on average, Libre is about 10% off from reference (lab) values.  That about matches many older-generation meters that are currently on the market.  Today’s latest meters, such as the Contour Next, Freestyle Lite, Dario and AccuCheck Nano are far more accurate, with results that generally fall within 4-6% of lab values.  The difference can be significant for those who are calculating insulin doses based on blood glucose levels.  The inaccuracy can be even greater when the blood sugar is rising or falling quickly – something called “lag time”.  Because Libre measures glucose concentrations in interstitial fluid in the fat layer rather than in the bloodstream directly, it takes time for changes in blood sugar to show up on the sensor.  Think of it this way:  Fingerstick blood glucose always gets the front seat in a roller coaster, fat-layer glucose always gets the back seat.  When the coaster is climbing, the glucose in the fingerstick will be higher than the fat layer.  When the coaster is dropping, the fingerstick will be lower.


Even if the accuracy of Libre matched the best blood glucose meters, there are still times when fingersticks are going to be needed:


  • During the 12-hour warmup period
  • When physical symptoms don’t match what Libre is displaying
  • Any time the receiver displays “Check Blood Glucose”
  • If the sensor comes off the skin accidentally
  • In the event the receiver is lost/broken or sensors are temporarily unavailable


And for many of us who have performed more fingersticks than we’d care to count over the years, there is a trust issue.  The clients we have in Europe who use Libre still check their blood sugar the old fashioned way just to make sure the Libre is working properly.  Some check a few times a day, some a few times a week, and others just during the first couple of weeks.


Super for Who?


Bottom line:  If you currently use a CGM and rely on it to warn you when your glucose is getting out of range, Libre is probably not for you.  If you’re not using a CGM and would benefit from being warned when your is getting getting out of range, then you should check into using a CGM other than Libre.  If you like the idea of having frequent BG data along with trending information but don’t want the alarms/alert intrinsic to current CGM systems, Libre may be a good choice.


For those who just rely on fingersticks and are susceptible to hypoglycemia, heck – even if you just detest doing fingersticks, Libre can be highly beneficial.  In addition to being a quick and frequent source of reasonably accurate glucose data, Libre provides that all-important direction you’re headed.  With all the decisions we make throughout the day related to our diabetes, knowing both the current glucuose value and where it’s headed lets us make much better decisions.  Think about it:  If your glucose is 118 and you’re about to exercise, take a test, drive a car, perform open-heart surgery, or just go to sleep, you can make prepare better knowing if you’re rising, falling or stable.


Super Summation


On the plus side, Libre has accuracy comparable to Dexcom, it is very easy to use, and does not require any fingersticks.  It provides a wealth of valuable information to the user with minimal discomfort and inconvience.


On the downside, Libre lacks the alert features incumbent to other CGM systems, and its accuracy, while good, is not as good as most modern fingerstick meters.


A prescription will be required to obtain Libre in the US.  It is approved for age 18 plus, but it can be used by children when prescribed “off-label” by a physician.


To learn more and for product updates, Abbott has set up a website:  If you decide to give Libre a try and want to learn how to react/adjust to the trending information and interpret the downloadable reports, give our office a call (610-642-6055).


To use new technology and really benefit from it… now that’s a SUPER combination!

By |2018-04-19T19:57:00+00:00November 18th, 2017|November 2017 Newsletter, Thinking Like A Pancreas Blog|33 Comments

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  1. Chole Gel November 20, 2017 at 10:50 am - Reply

    Thanks, Dr. Gary for providing details about Abbott’s FreeStyle Libre sensor.Certainly, this will help patients in making an informed decision whether Libre sensor is a right option for them or not. We are using Ambrosia’s NightRider BluCon since June, 17 and it is working like a charm. we are using it with xDrip+ app but could also be used with LinkBluCon app to see glucose reading every 5 minutes on the phone. In the recently released beta app of LinkBluCon iOS version user can also share reading on Apple Health kit while if you use xDrip+ then you can see glucose reading of your kid even when he is school, by using an app from NightScout.

  2. Joe Short November 20, 2017 at 11:16 am - Reply

    Good to see a well written article about Libre. I have been using Libre for 2 years and am active in an independent worldwide Facebook group of over 12,000 Libre users; about 9,000 take part at least once per month. We learn a great deal – both the good and the bad (thankfully not much of the latter!) Most PWD, both T1 & T2, consider it to be life-changing.Our biggest problems at the moment come from Abbott not being able to provide a reliable supply in the U.K. due to over-demand.
    We have discovered a number of workarounds which hopefully will also work in the USA version. An Italian company has developed an Android app that will read the sensor during the initial settling-in period – we don’t like losing that hour even if slightly less accurate (we know, so can compensate for dosing). It also gives an extra 12 hours at the end – we use this to save even more fingerpricks by using 2 concurrent sensors at changeover. We also insert 12-24 hours before activation. This allows insertion trauma to settle while not taking up sensor operation time – no need for your 12 hour loss! And we certainly can link data to carers and loved ones – even with Abbott apps!

  3. Joe Short November 20, 2017 at 11:32 am - Reply

    I should add to my previous comment that many consider the accuracy and safety provided by Libre to be far superior to BGM. Two critical aspects are often ignored when accuracy comparisons are made.
    The accuracy measurements are made with single spot readings. The BGM values depend upon “perfect” user precautions and sterile techniques. On the latter, independent tests show actual home use of BGM has current meters struggling to meet a 15% accuracy – one evaluation had less than 1/3rd complying with requirements.
    The other major difference is that the Libre takes a reading every minute. It stores less but uses 15 individual readings to provide the trend which you do highlight as one of the major advantages. As well as that we see the daily graph – again allowing us to judge from multiple individual readings about direction.
    Another major advantage is the provision of AGP graphs – a marvellous aid to Diabetes management.

  4. Denis B November 21, 2017 at 9:04 pm - Reply

    I’ve been using the Freestyle Libre for the past month and have managed to wreck two sensors in that time – once by bumping into a door frame, and the other by rolling over in my sleep. Be very careful when positioning the sensor to avoid these (very expensive) circumstances.

    Other than this issue, I’ve been very happy with the Freestyle Libre. My endocrinologist is able to see my BG trends for the entire day and has made several insulin dosage changes with the data.

    • alicia downs December 6, 2017 at 6:03 pm - Reply

      Thanks for the advice on the fragility of the libre Denis!

      • Ron K January 28, 2018 at 2:23 am - Reply

        Even if the sensor is ripped off the body the device itself is pretty durable, you’ll be able (in theory) to get previous readings from it.

  5. Jarek January 13, 2018 at 1:52 pm - Reply

    I am using european version for over 6 months and have following remarks:
    1. Lag is a problem vs finger pricking. You need to be super calm when your libre shows you are still going down while you ve already taken that orange juice. You know it is probably because of lag but it makes you nervous and you tend to take more carbs then required
    2. Touch screen is a pain – especially in cold environment – my second libre meter still has a problem with this so it is not a single meter problem
    3. Ux also could be improved – 24hrs before end of sensor time when you try to read sensor the meter shows a warning that sensor is soon to be replaced, in order to show bg reading you have to close this screen using a very small button in the corner of the screen. Since touch screen is a pain you are often (especially in cold weather) stuck and cannot read bg

    All in leaving above complaints aside I practically stopped finger pricking 🙂 I am swimming, climbing so really libre has helped me a lot.

  6. Donald Young January 24, 2018 at 2:47 am - Reply

    “Libre may help users cut down on the frequency and severity of lows, but only if the user scans the sensor every 5-10 minutes, including through the night. And that’s just not about to happen.”

    I would hate to be the person who before CGM had to stick their fingers every 5-10 minutes. The author must have been high when making this statement.

    My insurance won’t pay for a CGM. I can’t afford a Dexcom. This is still on the expensive side for someone receiving disability. But it’s better than what I have been doing and will give me and my doctor a better picture of my diabetes.

  7. Ron K January 26, 2018 at 2:44 am - Reply

    In the middle of my first 10 days with Libre and thus far I love it! I was diagnosed type 2 a couple years ago, I have struggled to get my blood sugar under control and refused to prick my sore fingers on a consistent basis.

    Libre is the perfect device for anyone newly diagnosed as it will help show how things like diet, medication, and exercise will affect your glucose levels at any given moment. You can test as many times as you like which is fantastic as you learn the navigate the diabetes highway.

    I have found a few downsides to the device so far.

    The first is the meter is touch screen but isn’t very sensitive and I have found myself hitting a “button” multiple times to get it to respond. The lack of response is annoying but certainly is not a deal breaker. I hope as time goes on the meter improves or I’ll be able to just sync the sensor with my Galaxy S8 instead of the meter.

    My second downside is what Denis B posted about: wrecking the sensor. I’ve almost caught the sensor on doors a few times but so far have been fortunate to see no damage or injury. I wonder if perhaps wrapping it up with a ace bandage or sweat band while sleeping would help? I did ask my doctor about using Libre elsewhere on the body (inner thigh for example), she told me that the sensors have only been tested and approved for use on the arm. If anyone else has used it elsewhere on his or her body, please post here!

    • nicoleroden September 14, 2018 at 12:55 am - Reply

      i have my libre on the inside of my arm so i don’t sleep on it or wreak it.

  8. Maurice Hamilton February 2, 2018 at 6:46 am - Reply

    This appears to be a nice equipment to keep a check on diabetes by effectively monitoring the glucose levels and review of Gary Scheiner is invaluable.

  9. Carol March 15, 2018 at 3:10 pm - Reply

    Do you think there will be a device in the future for animals with diabetes. It would be so much easier to use for animals since it is harder to apply the test strips twice daily for a dog.

    • alicia downs March 29, 2018 at 5:06 pm - Reply

      Actually one of our educators, Alicia is friends with a Vet who has been looking into pump and cgm technology in animals. of course the biggest barrier is the fur! But there are amazing and caring doctors looking into the cross over of tech.

  10. Alison March 18, 2018 at 7:01 am - Reply

    I’m just about to return to the Libre because I am fed up with the issues I have had with Medtronic CGM sensors and unreliability.

    I use a sweat band around the sensor on my arm if I am going to be particularly active, and also to stop people, especially young children, trying to pick it off me! Have also used extra taping to keep it securely in place.

    Thanks to Gary for his very useful reviews, and the comparison between the Dexcom and Medtronic CGM systems.

  11. Maurice Hamilton March 22, 2018 at 10:58 am - Reply

    Its really nice when an expert actually puts his neck out and threadbare discusses the advantages and disadvantages of a tool. Now users can go for it with more knowledge about it.

  12. Manny April 28, 2018 at 4:36 pm - Reply

    For what it’s worth I am a new user of Freestyle Libre. It has been nothing but a nightmare since I started using it on April 16. The reader and sensor have minds of their own. They will give me a reading when they want. All other time no matter what I do sensor is not found. I have received two replacements of the sensors with no change. I think the problem is with the reader but I can not make CSR accept that. So after three inserts, three painful removals after just a couple of day I do not have the results I expected. I am not even sure anyone is listening. It’s time to go back to finger pricking and return the Libre because I did not find any freedom.

    • alicia downs May 16, 2018 at 6:15 pm - Reply

      If you are able to get the Dexcom CGM we highly recommend it. the G6 even has zero finger sticks and one button insertion like the libre.

  13. Holly May 9, 2018 at 11:51 pm - Reply

    I have worn the device for three days. During that time it has been 10 to 50 points higher than my blood fingerstick readings. It would say I was 120 and I was actually 60. I’m concerned because it will not give me an alert if it’s 10 to 50 points higher than my true levels. I like that has gotten me to check my blood by fingerstick more often. But I was hoping to try to avoid that. Any suggestions?

    • alicia downs May 16, 2018 at 6:09 pm - Reply

      Hi Holly,
      Unfortunately we has similar issues with the Libre. Wearing it on an area that does not have much movement MIGHT help with accuracy, but since we can not calibrate the device, we are pretty much stuck with it.
      For the alerts and accuracy it is worth the fight if you can get a Dexcom CGM. The G6 even has improved accuracy with zero finger sticks, but you CAN calibrate when needed to improve accuracy.

  14. Debbie Alt May 22, 2018 at 11:37 am - Reply

    I’ve been using the Libre for 3 months. I find it to be a bit of a novelty, a nice idea but not as advertised. I have experienced issues with three of the first four sensors being faulty. Abbott was good about replacing them and I have since had no problems. My main concern, and a much more important one, is the accuracy of the device. When compared to a finger stick the Libre is between 15 to 40 percent off. For example, when I awoke the Libre read 67 and the Bg meter read 106. This type of error happens whether I am high or low or normal. In addition, the trending arrows have proven to be inaccurate as well. I am due for an A1C and my suspicions are that it will be higher than my normal since the Libre gives me consistently low readings. Has anyone else had this experience?

  15. Jay G. May 31, 2018 at 11:56 pm - Reply

    Recently had a very negative experience with the Libre and customer service. Sensor was reporting lows for a few days, I was treating them and when I checked against blood on a One Touch, it as 6.9 while the sensor was reading 2.9 – customer service is slow and does not even understand the product. They won’t replace the sensor nor the reader (cause you can’t delete all the false lows).

  16. Teresa W June 7, 2018 at 5:37 am - Reply

    I love it but cannot get the sensor to stay on me for ten days. I have two more sensors if they come off early then I will do away with this idea can’t afford $25 for a sensor every couple of days

    • alicia downs June 18, 2018 at 5:48 pm - Reply

      If you are having adhesive issues you might want to try skin tak or IV prep. these both help sensors adhere to the skin a bit better.

  17. Brent July 9, 2018 at 9:34 pm - Reply

    I cannot recommend these to anyone. I’ve been using them for about three weeks, and although mine have been fairly accurate (at least as accurate as a glucose meter), I’ve already had two come off. At $25 a pop that’s way too often. I have dry skin, only apply them after a shower and skin has dried, I use both alcohol swabs, and no lotion.

  18. Linda B August 21, 2018 at 2:06 am - Reply

    I have very sensitive skin. Has anyone had skin issues from the device you wear on your arm.?

  19. John August 21, 2018 at 4:37 pm - Reply

    I absolutely hate the 12 hour wait, it also counts towards the 10 day use of the sensor so in reality you are only getting 9 1/2 days of usage out of each sensor in the US, everywhere else you get 14 days and only need 1-2 hours for the warmup period. US healthcare is crap compared to the rest of the “developed” world. Maybe one day we will catch up.

  20. Jim Nemwan August 28, 2018 at 1:55 pm - Reply

    I have been using a Dexcom G5 for a couple of years. I started using a Libre two-weeks ago. Please note:


    Way less expensive than the Dexcom
    Accuracy is for me is on par with the G5 ( I had both on for the first week)
    Less involved when placing it on
    I like the scanner and the information, although it feels like a strong winds would break it.


    12-Hours Warm up
    Restricted placement area (Back of arm only vs. G5 on my belly or other better areas). It can be torn off very easily.
    Sensor adhesive area needs to be bigger (I’m using Tagederm to secure better) G5 was more adhesive to secure it.

  21. Susan September 2, 2018 at 11:53 am - Reply

    I have now used seven sensors. The first one worked great. After the first I have had nothing good to say about them. One didn’t work at all and the rest are horribly inaccurate and not even consistently inaccurate. They can very +/- 50 points from one reading to the next when compared to finger sticks. I am SO disappointed.

  22. ALAN MITCHELL September 7, 2018 at 1:18 am - Reply

    I have now used 3 sensors with the chilling results of high readings up to 3 full mmol points higher than the finger prick. I was told to check it with the finger some 5 to 10 minutes after doing a sensor reading. The finger prick was lower. I have reported the issue but I dont think anything will happen in fact I told them that it could be very dangerous for people that might say take more medication to lower the sugar levels. What I finished up doing was raising the levels on the meter to allow for the higher readings. Anyhow I am not willing to pay $90 every two weeks for the sensors but in saying that it can and will be a good device whit more work on it and the Government providing a rebate as they do with all other diabetes things.

  23. Garrett Bartholomew September 12, 2018 at 5:29 pm - Reply

    Very poor customer service. No support what so ever. Supplier and Abbot toss the blame back and forth. Like the Libre when it works, when it don’t good luck. Good luck getting a replacement. Too bad!

  24. Leslie September 14, 2018 at 8:04 pm - Reply

    I have had a terrible time keeping the sensor in my arms. I wake up and find it in my sheets or hanging from my arm. Are there any other reliable systems that don’t cost a fortune and have smoother sensors that won’t catch on things?

  25. Karen Sroufe September 21, 2018 at 4:13 pm - Reply

    I was bitterly disappointed with the Libre after receiving the buildup from my NP. My first sensor fell off after 30 minutes. The second sensor acted appropriately but the third sensor did not deploy; I felt it pierce my skin but it was still inside the applicator when I lifted it off. My glucose readings were all over the place and bore no relationship to my BG values, either being up to 20 points lower or 80 points higher with no discernable pattern. I was fortunate in that the company did accept it back and will reimburse Medicare as there is only a 15-day return policy (that I was unaware of). The chief drawback in that there was absolutely no education/training offered either by Abbott or the distributor. The next time I consider a CGM the first question I will ask is about face-to-face training.

  26. Joan October 28, 2018 at 6:21 pm - Reply

    Having issues with the Libre reading too low. It is typically 20 points or more lower than the Bayer Contour Link.

    Also, in Canada, Bayshore who is connected to the Libre sells one sensor for $89 . The Shoppers Drug Mart drug store wants $130 for the same thing. Seems like something is wrong.

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