Libre users- can you share what percentage is your time in target?

Hi all! I am using Freestyle Libre and so far I am managing to roughly be 60% ‘in target’, 10% ‘below’ and 30% ‘above’. My target is 5-10. I am wondering whether I should be pushing myself to get a higher percentage ‘in target’. Could you share your thoughts about this and what percentage of the time you manage to stay ‘in target’?

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How I wish the personal Freestyle Libre were authorized for use in the USA. I’d seriously consider getting one even if I did have to pay out of pocket.

During a period when I felt my BG had gone out of control completely a couple of months ago, my endo let me use a Freestyle Libre Pro from his office for 13 days. It didn’t allow one to read the results in real time, only to get a printout from the endo’s office after the 13 days were up. But in spite of the fact that I’d had some major changes that affected control, it turned out that I was in target 91% of the time, above target 2%, and below target 7%. It was set for a pretty wide target, though - from 70 to 180 mg/dl (3.9 - 10 mmol/L).

I’ve since learned what caused my BG craziness, have dropped the offending OTC medication, and my I:C ratios are back to what they were previously. But in spite of the fact that I’d had an A1c between 5.5 and 5.9 for over three years prior to the BG craziness and think it will likely be back to that level again now that I’ve removed the offending OTC, I think having the Freestyle Libre would give me better control. I’m sure I could cut the variability a lot and shorten any daytime hypos.

I’d certainly not be satisfied with only 60% of time in target, even though your target range is much narrower than mine was. But so much depends upon the individual’s situation. I’m elderly (75), and rarely do exercise that could cause major BG problems. If you are a younger woman dealing with monthly hormonal cycles or a younger man who is a triathlete, for example, there is no way you could expect to achieve as much time in range as I could. So much depends upon circumstances.

Thank you for sharing, Uff_da, it is inspiring to know that higher percentage IS achievable :slight_smile:

Not a Libre user but Dexcom user. My in range target is 3.9 - 8.9. It take work, but I always try to improve my in range numbers. Just take it a day at a time and build on that.

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Again - not a libre user but a Dexcom CGM user. My range is 3.8 to 8.0 mmol/l (70 to 144 mg/dl).

Someone on this board suggested trying for staying in target about 85% of the time. Once you hit that you can reduce your target.

I have been trying to improve my control over the last year. My numbers from a year ago did not look like this (far from it). I started trying to get to a range of 3.8 to 10 (180) 85% of the time and when I finally got that I moved the upper limit down.

Some things that helped me…
-getting a CGM and testing more often
-getting my pre bolus times right.
-eating less carbs per meal (like 30g or less)

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I pay out of pocket for my libre. I’ve been using it on and off since February. It is my first experience with any type of CGM. I find it so helpful for picking up trends and behaviours. It really helped me pick up trends in my basal requirements, which change over the month, and helped me fine tune handling morning blood sugars.

For the last 30 days Mine says 68% in target, 18% above target, 14% below target (27 low glucose events in past 30 days - Note: I do find that my libre sometimes runs low compared to fingersticks. So I also base corrects on how I feel and fingersticks). None of those lows have been rapid or severe, so they do not concern me.

30 day average blood sugar is 4.9. Hba1c last May was 4.6 (lowest ever). I average about 21 scans a day. I love the libre. I correct both ups and downs based on observed trends.

My target ranges are very tight:- set at 4.0 (72) to 5.5 (99).

I am on MDI (tresiba and novorapid) and I eat very low carb, combined with intermittent fasting.

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I note that my Dexcom G4 does the same thing but I think my doctor is skeptical of this reality.

Your regimen and results are awesome!

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I really don’t understand how Time In Range (TIR) is valid for the Libre. After all you have to manually take the readings, so they are inherently biases in the samples. How many times do you wake up at night and take a reading? If you spend a third of the day without readings TIR doesn’t make sense. You could have the same TIR despite being low or high all night. And since the Libre is used to provide actionable information you probably just get readings before a meal for dosing and then at specific times afterwards. Big parts of the day may not have any coverage. In order for TIR and statistics like standard deviation to make sense with the Libre you will likely have to make specific efforts to uniformly sample blood sugars throughout the entire day.

Either I don’t understand how the Freestyle Libre works, Brian, or you don’t. Now I don’t have a personal Freestyle Libre. I only used the Pro model for 13 days from my endo’s office. And I couldn’t see any of the readings for the whole 13 days, until he downloaded all the information from it. But here are charts from a couple of those days.

So if it provides the information to chart the BG over the day, why can’t it just calculate the time in range, which is the number in the second column at the right.

@Uff_Da I think what @Brian_BSC is saying is if you have to scan the sensor with the reader you are not really getting a good number of readings - especially at night. For example if you only scan during the day and are high all night (when you are not scanning) then your Time In Range will not really be valid.

I have seen people who strap a device with NFC - like their phone or an Sony SW3 over their Libre sensor and basically turn it into a CGM.

I am curious - when you used the Pro - did you have to scan, or did you wear an armband with a reader in it?

No, I didn’t have to scan. But neither did I get ANY information from it until my endo downloaded the information at the end of the time I used it. Then I could see from the charts the “continuous” information, which I could compare with my BG readings, which were obviously “spot checks.” And I could tell that for me the two compared closely enough that I’d feel comfortable trusting that the one I had gave reasonably accurate information during the period I had it.

So does the personal Libre not give you the continuous readout information after the fact? I really don’t think I need alarms, because I think I have my control figured out enough that I rarely have night time lows. But after the fact charts could be really helpful in determining how consistent a DP is at starting at a specific time, how a different bedtime snack might affect the pattern of night time BGs, etc.As it is, I do take a middle-of-the-night check when I have any reason to be suspicious that my BG might go low or high, but that’s just a single point in time. A chart after the fact, in contrast, could tell the story of what really happened, even if it is just a trend line, not specific numbers.

The internet tells me the Freestyle Libre PRO records glucose data every 15 minutes and stores up to 14 days of data.

That makes sense to me and also means that the time in range data is very valid.

Brian - the Libre is a great device which I used getting my T2 under control, understanding post meal BG spikes and 24hr profiling. In the U.S. I got my sensors and reader on ebay. There is now downloadable software for free. Sensors last 2 weeks and retail for about $75. For a new T2 IMO it is the best/most economic current approach to understanding and building a 24hr profile unless you can get a loaner dexcom.

The Libre samples every minute but only stores 8 hours on the sensor so you have to scan at least once every 8 hours or you will have gaps in the data if you are building trends. The “Pro” version averages a glucose reading every 15 minutes and can store glucose data on the sensor for two weeks. The Pro version is really for Endo’s to see a patients trend over the last two weeks. Here is a pretty good write-up

Here is the full user manual -


This ^

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Thank you all for sharing. After this discussion I feel inspired to try and get a higher per cent ‘in target’. I will try to achieve that by lowering the amount of carbs I consume. :slight_smile: It’s amazing so many people are willing to help and share ideas!

Thanks for everyone describing the Libre better. I clearly didn’t understand how it operates.


Hi, I am a T1 and have been using the Freestyle Libre for just over a year. It really is a fantastic monitor and, from what I have been reading, pretty much acts like a CGM. Initially I hated it and found the really highs and lows completely inaccurate. However over time, I am learning how it behaves, and now i honestly can’t go without it. I check myself pretty regularly, even during the night when I wake up, and the peace of mind it gives me is worth it. My HbA1C has reduced to 6.2, which is over 1.5 less than when I didn’t have it. Also using the monitor, I have gone low Carb, and found that, this is a much better way of eating. That is the good part of using this monitor, you can check every minute if need be, and get a good indication of what makes bgl’s rise rapidly. Like everything, you need to be mindful,and I still use the traditional glucose monitor when getting too high or low, just to be sure.


Hey Kelly, nice explanation of your experience. Question for you. My son currently uses the Dexcom, which has some behavior that is predictable, but like you said you need to get used to it. The Dexcom exaggerates the lows, i.e. stays low longer than a blood glucose measurement would indicate it should, but it doesn’t do that for the highs, it is pretty responsive to high blood sugar going low.

Can you articulate your experience in how the Libre acts with changing blood sugar, compared to your meter?

Is the inserter just the same as the other CGMs? My CDE said the purchase for her office would be a little too pricey. I think the system sounds wonderful, but I dont want anything as invasive as a standard CGM. Probably won’t have this in the US anytime soon anyway…

Hi Chris, the Libre has the same issues, the lower or higher my sugar
goes, the more inaccurate it becomes. However they do state that it has
a 10 minute lag, so I guess this needs to be taken into account. The
thing I like about it is the ability to correct within a very short
timeframe, and you can bolus with smaller amounts, as you can check
every minute, to keep it within target. When going high, if the arrow is
pointing straight up, I always check with the freestyle glucose monitor
which also has a pointer, and if it doesn’t show, I just ignore the
Libre and it suddenly turns around. Therefore, it takes some getting
used to. But its a godsend for me, I have so much better control now.

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