Is FreeStyle Libre 2 accurate?

Rosie9876

Active Member
Messages
40
Type of diabetes
Type 2
Treatment type
Tablets (oral)
First full day with Freestyle Libre 2 Plus, or any monitor. I was excited like having a new puppy. At last can identify specifically which foods are causing spikes. I was surprised that one potato waffle with a salad didn't. But I noted blood glucose was high overnight when I had poor sleep. But some posts claim it isn't accurate. Also it's poorly rated on TrustPilot. Any experience? I'm Type 2.
 

Pipp

Moderator
Staff Member
Moderator
Messages
11,192
Type of diabetes
Type 2
Treatment type
Tablets (oral)
I only tried it once, and it caused me a lot of discomfort with allergic reaction around the sensor. My preference is to use the old fashioned strips finger pricking and meter.

There are plenty of members who use the Libre, and hopefully some will come along and tell of their experience soon.
 

SimonP78

Well-Known Member
Messages
504
Type of diabetes
Type 1
Treatment type
Insulin
Generally they are ok, though they can sometimes have an offset (of a mmol/l though sometimes more).

I calibrate twice a day (ideally towards the top and bottom of usual range while it's reasonably flat) with a finger prick test - I'd suggest you do this too to ensure that the data you're looking at is actually valid.

Compression lows are a thing that often happens overnight, again best confirmed/ruled out with a fingerprick test. This is where the CGM reports low blood glucose while it's actually fine, because of pressure on the sensor, often from rolling over and lying on it while asleep.
 
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alanj

Well-Known Member
Messages
63
Type of diabetes
Type 2
About 2 points different according to customers services unless you have just eaten, most I have had is about 3.8
 
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Rosie9876

Active Member
Messages
40
Type of diabetes
Type 2
Treatment type
Tablets (oral)
Thanks. Is that to say if the reading is, say 5.7 mmol/L, it could be 7.7 or 3.7? Or even a greater disparity? That's huge. I do understand there's a delay, though, compared with the finger prick.
 

SimonP78

Well-Known Member
Messages
504
Type of diabetes
Type 1
Treatment type
Insulin
It depends though, they generally work pretty well and are roughly correct (i.e. I'm happy the number being generated is as accurate as that coming from the blood test meter), however they can sometimes diverge quite significantly. This seems to be on a sensor-by-sensor basis - if you've got a good one (or more like a good location/bodily reaction for/to the one you've fitted) it remains reasonably good across its life, though sometimes tapering off towards the end; if you've got a terrible one it also remains terrible).

This is why doing calibration tests is useful IMO.