Basics 0 – FAQ or questions and answers


The materials prepared on the basis of statements of members of the Freestyle Libre Polska group (Pl) on Facebook – and in part relate to national realities. Over time, if possible, we will complete the article with new questions and answers 🙂

Before you start reading

Check the questions and answers (FAQs) prepared by Abbott on their website

What is FreeStyle Libre?

FreeStyle Libre is a Flash glucose monitoring system that reads glucose directly from the intra-oral fluid using a sensor attached to the body. To make a measurement, just touch the reader to the sensor and the glucose level will appear on its screen.

Translating the principle of operation into peasant reason: a small circle is attached to the body for 14 days (a bit bigger than a PLN 5 coin), which scans our tissue every few minutes under the skin and reads the sugar level from it. In order to see what kind of sugar we have, we do not need to prick – just apply the reader to the above-mentioned circle (a special meter) and the result will be displayed on the screen.

More information and videos on this subject can be found on the site prepared by the producer, Abbott, as well as on the Internet, among others on this blog.

Who is Libre for?

FreeStyle Libre has been approved for use by persons with diabetes over the age of 4 years. Minors (from 4-17 years) may use the system under the control of an adult.

Abbott did not carry out tests on children under 4 years of age or pregnant women, which probably means that you can not be sure of glucose readings in tiny children and pregnant women. In the United States, the correctness of Libre in dialysed patients was also not studied.

Among the members of the group, however, there are both parents of children under 4 years of age and pregnant women who successfully use the system.

How to get an FSL?

Where to buy FreeStyle Libre?

Freestyle Libre is mainly sold via the website where you need to register and then log in and make a purchase.

Recently, there has been the possibility of buying in several online stores and in some pharmacies.

Free samples – how to get?

You can try to obtain free starter kits (samples) as follows:

  1. Receiving a reader and / or sensor from a diabetology clinic – ask your diabetologist about this possibility. Immediately after the introduction of FSL to the Polish market, many diabetologists were able to provide their patients with free samples. Over time, however, this is an increasingly rare situation.
  2. Receiving a reader and / or a sensor from the foundation – you should ask the foundation, which you should ask if they have available free readers and / or sensors.

Codes for free shipping

The shipment of each order placed on the FreeStyle Libre website currently costs PLN 25.50. From time to time there are codes for a free parcel, which can be used once. Most often, these codes are sent to the e-mail address to users who already have an account in the store. Sometimes you can get a code by calling the Abbott infoline on 800 800 800.

Most of us use our code for our own orders, so questions about free group forum codes are not well received. Before you ask “if someone has no code” check your e-mail address and / or call the hotline.

Payment for the order

Payments for FreeStyle Libre are only possible with a credit card and PayPal electronic payments. If you have a problem with making this payment, try searching for a group of people in your area who could help with the order.

Where to buy cheaper sensors?

FreeStyle Libre sensors cost approximately the same in every European country (255 PLN / sensor) in which they are available. It is not possible to buy cheaper sensors, unless someone wants to resell the sensor that he will not use or it is out of date.

The question about this on the group is not welcome, because if someone finds it, the cheaper sensors usually come from free parties that should have hit the people in need or are free promotional samples = not for sale!

The group also prohibits the sale of any products that are not a Libre reader and / or sensor. For sale, you can ONLY offer readers and sensors for which the seller has proof of purchase. The group is absolutely prohibited from trading Libre products received from the Foundation.

How it’s working?

Does the sensor application hurt?

Theoretically, NO. Practically – almost do not feel the moment when the needle punctures the body and introduces Teflon rureczkę, which will take the fluid to measure. The sound is more disturbing at the moment of “stamping” than the sting itself.

There are cases, however, that more sensitive hands (eg in children) feel pain when starting, but it is not large and should not last longer than a few minutes.

Users report that the feeling is similar, but definitely less unpleasant than putting the pump in the serter.

What can you activate the sensor?

The sensor should be activated with the Libre reader, because only this way of activating it allows the warranty to be maintained.

If it is not possible to activate the sensor with a reader (eg you do not have it or your sensor comes from eg Australia) then you can do it using a mobile phone with NFC mode and the GlimpS application installed on it. This application is only used to activate the sensor. Then you can use any other scanner and readouts.

What can the sensor read??

There are now several ways to read the measurement from the sensor:

    1. Readout with the factory reader FreeStyle Libre = the only method of measuring readings recommended by the manufacturer in Poland. WARNING! Currently, in Poland, only a factory readout reader allows you to possibly report a complaint due to the discrepancy of measurements! (Go to the question about complaints)
    2. Reading with a mobile phone with active NFC mode – an application must be installed on the phone that allows you to connect to Libre and download measurements. The manufacturer provides such an application, however, it is not yet available to users in Poland. There are other, unofficial applications that allow reading by applying a mobile phone – this is, among others xDrip, Glimp, LiApp.
    3. Reading with Transmitters – applied to the sensor, transmits data to the application on the mobile phone. You can attach it permanently which creates with Libre + Transmiter + mobile phone system of continuous glycemic monitoring (CGM).
    4. Reading with the Sony SW3 smartwatch – like the transmitter – the device after application (can be permanently attached) transmits data from the sensor to the application on the mobile phone.

How to prepare the skin before inserting the sensor?

Before attaching the sensor, the place where it will be attached should be degreased. In the case of adults, it may be necessary to shave or depilate hair from an area about 5-10 cm in diameter, but it is best not to do it immediately before inserting the sensor because the skin may become irritated. The manufacturer for each sensor + applicator kit attaches a special gauze, which should be enough to wash the skin, but from our experience this may be insufficient.

Members of the group recommend first to wash the skin with soap and water and then dry thoroughly. It’s best to wait a few to a dozen minutes after a shower or intense physical exercise because the skin may only seem dry. Before the application, wash the skin with a cotton swab attached to the sensor or similar. We wait a while for the alcohol to evaporate from the swab. After this treatment, we can assemble the sensor + applicator set according to the instruction attached to it and “nail the seal”;).

Where you can attach the sensor?

Abbott suggests that the sensor can be attached to the back of the arm. They do not provide any other proven applications for the sensor application.

However, members of the group, in addition to the place recommended by the manufacturer, successfully wear a sensor on such parts of the body as: thigh, abdomen, upper buttock … and report that the glucose readings are correct.

Before choosing the place of application, remember that it is better to choose places that are more sheltered – for example, the back than the side of the arm, so as to minimize the risk of hooking even the door frame: P.

When to set up and when to activate a new sensor?

The manufacturer recommends setting up the sensor and activating it immediately. After 60 minutes, the first readings of the sugar level are possible. However, for some people, the results after 60 minutes of being put on for some time may be incorrect. At the helpline, or from Abbott’s representatives, we will find out that such abnormalities can occur up to 72 hours after the sensor is installed.

It is best to apply the sensor when you have a stable, good sugar level. So it is better not to put Libre on just after a meal or to give insulin because then the first measurements will definitely not be correct.

Due to problems that may appear during the first 3 days of use (incorrect measurements), some members of the group recommend applying the sensor 4-24 hours before its activation. Such a method has no medical justification and is recommended only on the basis of the experience of some of us. Perhaps due to this delay, the sensor has time to get saturated with the liquid from which it reads the sugar. This method will not hurt or shorten the sensor’s performance, as each sensor should operate for a full 14 days from its activation (the first “scan”) and not the assumption.

If you have problems with incorrect readings during the first days of use it will not hurt to try to set up the sensor a little earlier and only after a few-tens of a few tons of hours to activate it. Maybe this solution will help you;)

How to interpret the results?

The FreeStyle Libre system shows the numerical value of the level of sugar in the intra-oral fluid (in the blood that is in the tissue under the skin). These measurements can be delayed by 5-15 minutes in relation to blood measurements, e.g. from the finger. This means that if we measure the blood using a regular glucometer, the result will be in line with the measurement made Libre only after 5-15 minutes.

But apart from the numerical indications of the blood glucose level, Libre also shows trends – ie arrows indicating whether the sugar “goes up” or “flies down” and how quickly it happens. The arrows, in conjunction with the graph, allow for better interpretation of results and for prediction and prevention of, for example, hypoglycemic events.

If and when to test the meter?

The producer informs that “why sting when you can scan”, but the reality is not always so colorful. The instructions contain information that in the case of hypoglycaemia (eg indication of LO) and high indication (HI) it is best to confirm the result with a test using a glucometer before giving the correct correction. In addition, in case of any doubts arising from a bad mood, which may, for example, indicate hypoglycaemia, although Libre shows good sugar level, you should also check whether the result is certainly correct.

Users’ experience shows that one can not even stutter for weeks, if the indications are consistent with the frame of mind and we scan ourselves looking not only at the numbers but also on the graph and arrows. But most of us check the blood from the finger once or several times a day. The number of scans performed with the help of the reader often exceeds the number of 20 🙂

Is it possible to calibrate the results?

Czytnika FreeStyle Libre nie da się kalibrować. Ma on wbudowaną fabryczną kalibrację – czyli sam interpretuje pomiary i wyświetla wyniki na podstawie swojego oprogramowania.

Kalibrować można tylko aplikacje na urządzeniu dodatkowym, czyli np. na telefon lub tablet.

How long the sensor works?

The FreeStyle Libre sensor has a pre-installed blockade that blocks its operation with the reader exactly after 14 days of activation.

However, many users using the reader to read not only the reader, but also mobile phones or transmitter confirmed that after “turning off” the sensor can be scanned by another device even for a few days. If the sensor was activated (started) with the GlimpS application and not with the Libre reader, it was possible to “drag” it for up to 8 days! However, it should be remembered that activating the sensor with something other than the Libre reader is associated with the loss of the guarantee. So something for something;).

If you want to extend the operation of your sensor, start scanning it with your phone within 14 days. Calibrate it in advance so that you can be sure that the readings are correct and then use as much as possible;)

How to recognize that the sensor “ended its life”?

If you only scan with the FreeStyle Libre reader, an appropriate message will appear on the screen indicating that the sensor has finished working. If it happened within 14 days of its activation then you can try to file a complaint, as this should not happen if the sensor is used correctly.

Even after this message appears, you can still scan the sensor with a mobile phone or using a transmitter / smartwatch. However, this can not be done indefinitely. At some point the results will start to repeat and either the reading will be set on one level and the application will always show the same (straight line on the graph), or your chart will start repeating – the last few hours (usually the last 8h recorded) measurements will be infinitely inundated on the chart = results will cease to be valid.

Can the phone damage the sensor during scanning?

Some applications show a warning that some phones may damage the sensor during scanning. This case may have occurred on the group once in 7 months since the introduction of Libre to the Polish market. There is no confirmed information on this subject, but there are information from many users who use different types of phones = works.

Remember that you scan with your phone at your own risk, but most of the group members do it successfully.


Readings from Libre on many devices

If you use a mobile phone, smartwatch or transmitter to read results from FreeStyle Libre, these results are sent to the phone, which can forward them – eg. For another phone with the application or to the NightScout application.

Once the data is available in NightScout – it can be downloaded and displayed on various other devices: no PC or Mac, on phones (and with Android and IOS = IPhone), on tablets (also iPad), watches, etc. – everything that has Internet access and a standard browser.

Information about the NightScout application and its configuration can be found here:

The influence of Libre on the management of diabetes

What effect Libre has on the outcome of HbA1c?

According to information provided by Abbott on Advanced Technologies and Treatment for Diabetes (ATTD) in Paris on February 15, 2017, users of 50,831 readers who have scanned 279,446 sensors have improved HbA1C from 8.0 to 6.7%



What to protect against unsticking?

Members of the group suggest to protect the sensor from peel-off, if it seems that it can peel off or we will be exposed to heavy use – eg physical exercise, swimming pool, rapid movements. Sensors are not cheap, so prevention is better than cure;) And in some of us, the skin just works worse and the sensor gets worse.

The sensor can be sealed:

  1. Tejps – kinesiotherapy tapes (patches for kinesitherapy), which can be obtained primarily on Ebay but also in medical and stationary stores and on the Internet.
    Tegaderm – plasters with breathable film are also available on Ebay and in medical stores.
    Adhesive bandages – for purchase, among others in veterinary clinics, medical stores and on Ebay.
    Sports bands – so-called wallets available, among others in sports stores, but also from time to time in stores.

Differences in measurements (Libre and glucometer)

Many users complain about the differences in the measurement of blood sugar made by FSL and the meter. Before we panic that Libre is working badly, we must take into account and understand several important factors:

  1. According to the information they provide, among others Abbott’s representatives and consultants at the FreeStyleLibre hotline may show incorrect measurements up to 72 hours after the sensor has been installed and activated. Read how the members of the group deal with it
  2. FreeStyle Libre will never show exactly the same results as your meter. If you manage to match these perfectly matching measurements, this is a pure chance and means that your sugar is rather stable at the moment, but do not expect such measurements every day at any time.
  3. FreeStyle Libre shows a measurement that is delayed in relation to the measurement directly from the blood (eg from the finger) about 5-15 minutes. If your sugar is quickly growing or falling, there may even be very big differences. Consider whether you have just eaten a meal or if you have recently given insulin.
  4. FreeStyle Libre, just like any glucometer, has the right to be “confused” by 15-20% compared to the real sugar level in your blood. You can not measure this real sugar level with a meter – you can read it only by testing the blood in the laboratory. All other measurements, be it a glucometer, dexcom, Libre or other devices have their limit of measurement error = they can indicate a little more or a little less than it really is.

How to calculate if the differences in measurements are more than 15%?

WARNING! Below, some complicated calculations will appear;)

You can base on an example:

1 measurement: Libre meter = 100 = A

2 measurement sensor Libre = 180 = B

Possible measurement error on the meter A = range from 85 to 115

A – 0.15 * A = 85 = a1

A + 0.15 * A = 115 = a2

Possible sensor measurement error. Libre B = range 153 to 207

B – 0.15 * B = 153 = b1

B + 0.15 * B = 207 = b2

If the compartments do not overlap, that is:

a2 <b1 if the blood measurement is higher than with Libre

a1> b2 if the blood measurement is lower than with Libre

as in the example above (115 <153) and such differences happen to you at least 3 times in a row you have a very high probability of accepting a complaint and receiving a new, functional sensor.

Report a complaint?

  1. JIf your sensor has been activated by the application on the phone or in any other way without using the Libre reader, the complaint may not be accepted. Starting the sensor through the application is associated with the loss of the warranty!
  2. If you noticed big differences in measurements that last even though the sensor has been activated for more than 72 hours (3 days) and you have completed 3 series of measurements 1) Libre + 2) Libre sensor and recorded measurements in each series are different by more 15% is probably your sensor has been down and the complaint should be accepted.
  3. If your sensor has peeled off the slice = the slice has been left on the body and the plastic device has detached itself from it – in most cases such complaints have been considered positively.
  4. If your sensor has gone off together with the plaster before the 14 days have passed – think first of all whether it was not your fault – did you degrease your skin before application? Have you not hooked up with a sensor? Have you not wet the sensor for more than 30 minutes in water? – if you think the mistake is with the manufacturer, try to file a complaint, but it may not be included.
  5. If the sensor or reader has stopped working – readings from the sensor are impossible or the reading continuously indicates LO or HI; the reader does not start even though it has a charged battery; after applying the reader to the sensor on the screen for a long period of time (eg above 2 hours), the message “Reading from the sensor is impossible” appears. Please try again in 10 minutes. “- in such cases, most complaints are included.
  6. If you received a sensor and / or reader as part of a promotional campaign / as a free sample / donation from the foundation – you will probably not be able to advertise it. Free samples (such as samples such as cosmetics) are not subject to complaint. Sensors and readers received from the foundation can sometimes be advertised, but only through contact with the foundation from which you received the equipment. This foundation will report a possible complaint on your behalf. Similarly, for example, with the readers received at the clinic or a representative – try to contact them and ask if it is possible to complain about your equipment.

How to report a complaint?

If your sensor has failed and it is not the fault of improper use or mechanical damage (eg hooks on the door frame, too wet soaking of the sensor, attach it to the forehead;)) then you can try to report a complaint by phone.

Complaints are accepted at the Abbott infoline

The hotline is open on business days (Monday – Friday) between 8am and 5pm.

WARNING! Arm yourself with patience. Most of us wait a long time for a connection.

What you need to know before you call:

If you want to report incorrect measurements (eg large differences between blood measurements and Libre measurements) you must have: a Libre factory reader and blood sugar measurement strips (Optium Xido) using this reader.

Then you have to perform three series of measurements:

1) you measure sugar from the blood glucometer = reader Libre,

2) after 10-15 minutes, you scan the Libre sensor with a reader.

And three times.

If the measurements recorded in each series are different by more than 15%, it is likely your sensor has failed and the complaint should be accepted. Remember that these measurements must be stored in the Libre reader’s memory so that the manufacturer can confirm the wrong results.

WARNING! Under no circumstances should you throw away the sensor you are reporting to the complaint. First of all, remember about the implementation of 3 series of measurements, which will be the basis for the complaint. If the sensor has stopped working or its operation is clearly incorrect, you can remove it, but keep it because you will have to send it to Abbott in a special envelope, which you will receive after filing the complaint.

Does the sensor work after the expiration date?

Generally every sensor has a date of expiry printed on the packaging, after which it should not be used, but it happens that we will not be able to use all the sensors ordered before this date passes. Sometimes, unfortunately, these are rather short dates, so it is better not to order too much. Some members of the group successfully used sensors that were overdue by up to 2-3 months and did not notice any errors in their operation. Such sensors can be normally activated. The only drawback was the weaker holding the glue – but we can do it: stick it with, for example, tympem.

Will the sensor purchased in another country work with your reader??

In the case of European countries = YES. In the case of sensors from other parts of the world (eg from Australia) it may not be possible to activate such a sensor with a Polish reader, but you can run it using a mobile phone and GlimpS application and normally use it for a full 14 days, eg by scanning the phone. However, it must be remembered that the sensors activated by the application lose their guarantee.

One Comment

  1. Great FAQ Marek. One further thing to note for the free postage from Abbott – if you add an order to your basket on the Abbot website, and complete your details, but don’t complete the purchase, sometimes after 24-48 hours they will email a code for free postage. This will usually be the second email they send. This doesn’t work all the time, but will work occasionally. There’s also sometimes universal codes published on the Abbott twitter feed or in their newsletter.

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