I confess: When I first heard about the new FreeStyle Libre from Abbott, before ever using it, I thought it sounded like a stupid product. It was billed as sort of a magic wand that used a sensor stuck onto your body like a regular CGM (continuous glucose monitor) but less powerful. You'd have to wave the monitor over the sensor to get that poof! And like magic it would tell you your blood sugar.
This so-called Flash Glucose Monitoring seemed like a waste of modern D-tech to me.
But within minutes of booting up one of two sample sensors provided for review, I knew Abbott had a potential game-changer on their hands.
Priced right, and covered by insurance, I knew in a flash that Abbott was poised to make a fortune and to re-write the rules of glucose monitoring. And for once, this economic juggernaut would also benefit the vast majority of people with diabetes, especially those living with type 2.
The FDA approved this new system in September and launched it the week of Thanksgiving, and Abbott offered us at the 'Mine a test-drive along with some others in the Diabetes Online Community. Here are my initial impressions of the Libre system, after using it for a couple weeks.
Abbott FreeStyle Libre Basics
Let’s backup to offer a bit of background, for starters.
The Libre system consists of a combined sensor/transmitter, and a handheld receiver that Abbott calls a “reader.”
Sensor/Transmitter: By comparison to the existing CGM sensors on the market, this one is ultra-flat and about the size of a quarter. Literature from Abbott tells us it must be worn on the back of the upper arm. A disposable inserter that comes with each sensor makes placing the sensor quick and painless; and it stayed firmly attached to the back of my upper arm for its 10-day run. It has a hard shutoff, meaning you can’t wear it longer than that FDA-approved wear-time like you often can do "off-label" with the Dexcom and Medtronic CGM sensors. Personally, my skin also didn’t like the adhesive and I suffered suffered bothersome itching that caused my skin to break out in a nasty rash under the disc.
Handheld Reader: This device is lightweight and has a backlit color touch screen that I actually found somewhat unresponsive -- more of a stab screen than a touch screen. Its form factor is identical to the FreeStyle InsuLinx glucometer, and in fact, the reader can double as a glucometer. We didn’t get any of the compatible Precision Neo test strips with our review kit, so I was unable to test out that arm of the system, which is a pity as I wonder how the Libre’s readings would have compared to its own test strips -- especially because, as you’ll soon see, they didn’t compare well with mine.
No 'Continuous' Data or Alarms: Unlike most other patient CGMs past and present, the system does not routinely send data to the monitor, nor can it alert the user to an impending low, or an out-of-range high. Libre is totally passive. It might even be better to think of this first-generation Libre as a “passive CGM,” rather than a straight-up CGM comparable to the two currently on the market. Essentially, you have to ask it what your sugar is. If you are 52 and dropping, the system knows, but it won’t warn you unless you ask it. In my view, this makes the system of questionable value for anyone (type 1 or type 2) on fast-acting insulin, as does the 12-hour warm up at the start of each sensor. But for the other 90% of the diabetes population, that might not matter. Or put another way, the other benefits of the system could well outweigh these weaknesses for the majority of potential users. Still, the issue of no alerts is a huge one for me.
No Calibration: In a first-ever for a device approved here in the U.S., this alternative glucose monitoring system does not require fingersticks for calibration. In fact, it won’t accept them. The Libre sensor figures out your blood sugar all on its own. This potentially removes the weak link in the CGM chain, as many of the fingerstick test strips on the market are of questionable accuracy, plus the act of calibrating is not without problems itself. But on the down side, if the sensor is running wide of the mark, there’s no way to nudge it in the right direction.
As a self-described passive CGM system, the Libre measures glucose every 60 seconds and stores the data until the system is queried. Abbott calls this a “scan,” requiring the user to basically wave the reader over the sensor to get the BG result. It’s fast, easy, and can be done over any type of clothing, even thick jackets.
When my reader first came to life, I was greeted with an 8-hour CGM graph screen. Of course, it was largely blank, as the reader doesn’t start recording until a sensor comes on line after the 12-hour warmup period. But this was my first clue that Libre, while being less than a full-fledged CGM, could indeed provide much more value than simple fingerstick testing.
While it doesn't provide alarms, the Libre features a trend arrow showing the direction of BG change (up, down, or level) and a trace of meanderings of the sugar levels over the last eight hours. Abbott calls these increased glucose perspectives “actionable insights.”
I began to imagine a world in which everyone with diabetes could easily and quickly see not only what their blood sugar is as often as they want -- at no extra cost for all the multiple test strips needed -- but also what direction the sugar is moving.
The potential value to patients, and doctors, is immeasurable.
And there’s more.
Just like most traditional glucose meters, the Libre features average glucose data screens for 7-14-30-90 day trends. (Although buyer beware: even though I’ve been wearing the system for less than 20 days, the system dutifully reports 30 and 90-day data, which in reality, do not exist yet). With the Libre, you can access any 24-hour period and view the sensor trace for the day, and other on-reader features include a daily pattern analysis, time in target data, a low glucose event log, and stats on sensor usage that includes the number of scans per day.
So to me, the Libre IS a game-changer because it adds context to glucose readings, without the need for loads of high-cost test strips or a full-fledged CGM system that's also more costly and probably more complex than many patients need.
In short, the Libre is pretty slick, and could be perfect for both docs and many patients, with one caveat…
What About Accuracy?
In my two-sensor test-run of the Libre, a problem I found was the system’s accuracy.
Both sensors ran low for the majority of the time they were on my body. At first, I scanned a lot. But as the numbers remained depressingly off versus my other devices, I found myself scanning less and less.
After the first sensor booted up following the 12-hour warmup period, it was a full 20% lower than my Dexcom G5, which requires two calibrations per day that I perform with the
At first I told myself, 'Well, most CGMs are a bit off the first day.' Of course the devil on my other shoulder was saying: 'Really? After 12 hours? C’mon, you’re kidding yourself.'
And I was.
This steadfastly low trend continued for three full days, though it did pretty accurately follow the rolling waves of my sugar through highs and lows.
For a few hours on Day Three, the Libre was in sync with my G5 but it quickly returned to poor performance. I’d hoped it was a site issue, but the second sensor inserted on my other different arm ended up being slightly worse.
Looking back on some of the recorded data for seven days, with a mix of both the first and second sensors, my Dexcom showed a somewhat depressing average of 206 mg/dL, while the Libre was 21% less at an average 170 mg/dL.
That’s just too far from the mark, for me.
In comparison to Medtronic’s newest Guardian 3 CGM sensor that I tried out earlier this year with the Minimed 670G system, I think Libre was worse on the accuracy side. But Medtronic’s system varied a lot from sensor to sensor. It was running 10-12% low, which by comparison is better than this pair of Libre sensors.
Of course there’s always the possibility that I am an anomaly, i.e. that something weird about my body’s chemistry throws off the sensor... Although apparently I’m not the only one finding the readings low.
Libre Pricing and Availability
Apparently, the insurance game is still afoot and it's TBD whether that will happen anytime soon. For now, the FreeStyle Libre is available in national US pharmacies like CVS, Kroger, Rite Aid, Walgreens and Walmart. You need a doctor's Rx to get this device. For those interested in pricing, here’s the skinny:
- The suggested retail cost for the sensors is $36 each -- less than Dexcom sensors at $88 each and Medtronic’s CGM sensors that ring in $94 for the Enlites, and $108 each for the new Guardian 3. Prices may vary depending on the pharmacy.
- The handheld receiver is only $70, practically free compared to the four-digit price tag of a Dexcom system and the even higher cost of a Medtronic pump-CGM system.
And there is still the additional cost of fingerstick testing.
Yes, I know we’ve already established you don’t need to calibrate this with fingersticks like you do with the Dexcom and Medtronic CGMs. Abbott refers to that as “routine fingersticks.”
But the Libre does not entirely eliminate the need to have a traditional meter with test strips on hand – necessary during the 12-hour warmup window, when the accuracy isn’t up to par, or in other situations like when you’re feeling under the weather with a common head cold or somesuch.
So yes, when it comes to cost… you still must factor in the cost of some test strips as "adjunct" and backups.
Naturally, Abbott is soliciting users at the moment with aggressive marketing and even TV and radio ads.
As far as hitting the competition, they're mostly focused on Dexcom since that’s pretty clearly the most accurate and preferred CGM out there on the market. Abbott is offering anyone on a Dexcom a free Libre trial.
In their radio and TV spots, they're specifically calling out how the Dexcom CGM sensor doesn’t sit well with acetaminophen -- though that’s not going to be an issue for long as the FDA-submitted G6 solves that problem.
My gut is that the Libre, if it can be made more accurate, or if it’s more accurate for other folks than I found it to be, will most benefit type 2s, who with limited fingerstick checks are not currently able to learn much from testing to help with their diabetes control.
Wishing for a Win
It's tough testing a product that has the potential to be a big game-changer and a win for many people, only to find that I'm not necessarily one of them (based on this test-run experiment).
I am rooting for Libre. I really want it to work. And I did find it to be a brilliant middle ground between the somewhat useless (in small volume) traditional test strips and the fully featured (but pricey) CGM.
It could be wonderful for so many people, if the accuracy is improved. Meanwhile for me, as I suspect it will be for others on intensive testing and insulin dosing therapy, the initial scanning experience was something of a disappointment.
Other Diabetes Community Reviews
We've also been seeing others in the DOC who have had a chance to do early reviews of the Freestyle Libre, and we're keeping a running list of blog posts that we've come across. If you see others, please leave a comment below and let us (and all readers) know about them, too!
Kerri at SixUntilMe: Managing Expectations with the Libre
Jewels at SheSugar: A Nurse's Review
Stephen at Happy Medium: Trying the Libre (Part 1)
A Sweet Life: Is the Libre Right For You?