Freestyle libre 2 giving false highs

The only thing that I have found with Libre 2 compared to the first release is that it takes longer to bed in.
I need to insert my sensor 48 to 72 hours before activating otherwise, for the first day or two, it seems to report random numbers.

Most reports I have read suggest L2 is more accurate than L1.
I use xDrip to read mine as it allows me to calibrate when Libre is out so maybe I don't notice as much.

The other thing to be aware is that Libre (and other CGMs) are not accurate when high (or low) and often over read. I think this is partially to do with the accepted error tolerance being a percentage but I think it is more than that/

Hi,
I can't offer much in the way of a solution I'm afraid but I can empathise. My son is similarly slim and uses a Libre2 and occasionally we have a sensor that reads up to 3mmols higher. As he's a minor I usually 'plug it in' and we use the back of his arm - which I suppose is the underside if you hold your arm our, palm facing upwards at the fattest bit. Curiously it's usually his left arm that we get the dodgy readings from. He's right handed so maybe his left arm is lightly leaner and there isn't as much fat layer for the sensor to use?
We apply the sensor 24 hours before it's activated too.
I usually phone Abbott and they send a replacement.

Have you looked at your Libreview online graph, sometimes the graph reads differently to scans, often lower peaks. It's as if a scan is trying to anticipate your BG based on where it was going 15 mins ago.

This is an old thread but I have just encountered the same discrepancies . I had an incident of genuine high glucose level ( though not I now suspect as high as Libre indicated), but since then it has indicated regular higher than expected readings . After two days of a few random glucose tests I have now had to double check every test and the Libre sensor is consistently recording 4.5 higher than glucose readings. I understand that the different measuring methologies can provide slightly differing timing for changes in levels , but the discrepancy is happening when both levels are steady over a significant period.
It is very annoying because the falsely high readings have completely ruined the average calculation, the estimated HBa1 and distorted the weekly trends.
They are very expensive to buy privately and my GP was already a reluctant prescriber - forced into it by consultant, so I do not fancy my chances of seeking an early replacements prescription if it is failing.
Someone mentioned getting a replacement direct from Libre - anyone with experience of that? Do they just want it back to test or will they issue a replacement ?

Abbott are very good at replacing faulty sensors, so I'd give them a ring on Monday @Nick25

Hopeful34 said:

Abbott are very good at replacing faulty sensors, so I'd give them a ring on Monday @Nick25

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Thanks for prompt reply. I will try them , and maybe report back so others know the outcome.

Nick25 said:

Thanks for prompt reply. I will try them , and maybe report back so others know the outcome.

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Abbots very efficient. Give them a call today if you can. 0800 170 1177. Good luck

I too have had this issue so good to know I am not alone. I'm type 2 so not so critical but I'm trying to get into remission. The first ones I had were fine then I had several that were reading high. Libre replaced 2 - it's pretty easy you can just email them. Now I have another and it's still reading about 2mmol higher. On the third day now. I'll leave it and see how it goes and next time try leaving it for 48hours before starting.

Speedbird said:

Abbots very efficient. Give them a call today if you can. 0800 170 1177. Good luck

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Since this thread has been resurrected I confirm that Libre did replace two sensors when I contacted them. They did go through a series of questions to check the issues and asked that I return the faulty sensors.To their credit they did replace within 48 hours.

That said, I do agree the Libre seems very prone to exaggerating the high and low readings. It is difficult to ignore a 3.8 and falling and easy to over compensate for a 16 and rising - the only solution being to cross check with a blood test - completely defeating the point of the system.