FreeStyle Libre 3 safety notice: when to double-check a low with a finger-prick
Abbott’s safety notice warns some FreeStyle Libre 3 and Libre 3 Plus sensors can read falsely low. How to check yours, get a free replacement, and stay safe.
Abbott has issued a safety notice about the FreeStyle Libre 3 and Libre 3 Plus, the glucose sensor you wear on your arm. Some sensors can show a glucose reading that is falsely low, lower than you actually are. Affected sensors are replaced free of charge. Two simple things keep you safe: check whether your sensor is affected on Abbott’s sensor-check website, and treat how you feel: if you have the symptoms of a low, treat it straight away and never let a test delay you. The finger-prick is for the other case, when a low reading surprises you but you feel completely fine, so you can check what is really going on before you act on a number that may be falsely low.
- The FreeStyle Libre 3 and Libre 3 Plus are continuous glucose sensors (a CGM) that read your glucose from your arm and send it to your phone.
- Abbott issued a field safety notice (a safety alert from the maker) that some sensors can show falsely low readings.
- A falsely low number can lead someone to over-treat with sugar or hold back insulin they needed, so it matters day to day.
- Check your sensor’s serial number on Abbott’s sensor-check website (FreeStyleCheck.com) and request a free replacement if it is affected.
- Until then, confirm a surprising low with a finger-prick blood test, and treat how you feel, not the sensor alone.
What the safety notice actually says
On 25 November 2025, Abbott issued what is called a field safety notice, which is a maker’s formal safety alert, about certain FreeStyle Libre 3 and Libre 3 Plus sensors. The issue is specific: some sensors can display a glucose reading that is falsely low, showing a number lower than your real glucose. Abbott is replacing affected sensors free of charge, so you should not be out of pocket to put it right.
The first step is to find out whether your own sensors are among those affected. You can check your sensor’s serial number on Abbott’s sensor-check website, FreeStyleCheck.com, and request a replacement if it is on the list. Your pharmacy or diabetes team can help if you are not sure how to check or want a hand arranging the swap.
How to stay safe while you check
The everyday risk from a falsely low reading is over-treating. If the sensor says you are low but you actually are not, you might eat fast sugar you did not need, or hold off insulin, and end up high afterwards. The simple protection is a finger-prick: if a low reading surprises you, or does not match how you feel, do a blood test before you act on it. A meter and strips within reach make that easy.
The flip side matters just as much. Do not talk yourself out of a genuine hypo. If you feel the symptoms of a low, shaky, sweaty, confused, suddenly tired, do not wait for a device to agree with you: treat it. This notice is not asking you to distrust every low. It is giving you one clear cross-check, the finger-prick, for the times the sensor and your body do not tell the same story.