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IntroductionInitial 24-Hour Adjustment PeriodCommon Sensor Issues of Libre 3 and Their SolutionsMore Common Reasons Behind CGM Accuracy ProblemsCommon CGM Accuracy Issues and SolutionsHow Accurate Are the Libre 3 SensorsIs Your Faulty CGM Still Not Working Right?Conclusion IntroductionThe FreeStyle Libre 3 Continuous Glucose Monitoring (CGM) system has been praised for its impressive accuracy with a staggering 7.9% MARD (mean absolute relative difference), even surpassing the FDA’s required parameters. Its 14-day sensor delivers reliable readings that help users manage their diabetes effectively. However, like any medical device, users may occasionally experience accuracy issues. Here are some potential causes and solutions for Freestyle Libre 3 accuracy problems.
Initial 24-Hour Adjustment PeriodWhether you’re using the FreeStyle Libre 3, Libre 2, or even a Dexcom CGM, the first 24 hours after applying a new sensor can result in inconsistent readings. This occurs because:
The sensor is acclimating to the subcutaneous environment. The body’s tissue may take time to adjust to the filament.Solution: To minimize disruptions:
Apply the new sensor on the opposite arm a day before your current sensor expires. Monitor closely during this period using fingerstick tests if necessary. Common Sensor Issues of Libre 3 and Their Solutions 1. Sensor Error MessageA “Sensor Error” message indicates the system’s inability to provide glucose readings. This could be due to:
Calibration issues. External interference or incorrect sensor application. What to Do: Tap the “i” information symbol on the app for specific instructions. Recheck after the suggested duration. If the issue persists, fill out the online sensor support request form or contact customer care at 855-632-8658. 2. Replace Sensor MessageThis message may suggest a fault in the sensor. It typically occurs when the system detects an irreparable error.
What to Do: If 14 days he passed already, remove the sensor and start a new sensor. If this message appears before the 14-day wear period ends, claim a replacement sensor through Abbott’s support. 3. Readings That Don’t Match SymptomsIf your glucose readings don’t align with how you feel or your symptoms:
Perform a fingerstick test to confirm your blood glucose levels. Cross-check the FreeStyle Libre 3 readings with a traditional blood glucose meter. 4. Sensor Error – Try Again in 10 MinutesIf your FreeStyle Libre 3 sensor is showing the “Sensor Error – Try Again in 10 Minutes” message, don’t worry — this is a common and temporary issue.
It usually occurs when your glucose levels change too quickly (for example, after eating, exercising, or taking insulin) or if the sensor experiences a brief signal or temperature disruption. The Libre 3 continuously measures glucose through interstitial fluid, and when those levels shift rapidly, the sensor may require a few minutes to stabilise before providing accurate readings.
What you should do:
Wait the full 10 minutes, then rescan. Make sure your phone’s Bluetooth is on and the Libre 3 app is active. Avoid bumping, pressing, or sleeping on the sensor. Stay in a normal temperature environment (not too hot or cold). If the message keeps appearing or lasts longer than 30 minutes, contact Abbott Support — your sensor might need replacement.
Engaging in extreme workouts can loosen your sensor, leading to incorrect readings, often false low readings. Using overlay patches, like CGM Patches, may help prevent this issue.
This sensor has not undergone X-rays, MRIs, or CT scans. Thus, removing before you undergo a scan and applying a new one afterwards may be helpful.
High doses of vitamin C: also known as ascorbic acid, may interfere with readings and show elevated blood sugar levels, as confirmed by ScienceDirect, this increases the chances of hypoglycemic events. When taking such doses, it’s important to use finger sticks.
When to Seek Help:If discrepancies persist, depending on the issue, consult Abbott’s customer support or your healthcare specialist.
Did you know?
Freestyle Libre 3 Plus Sensor is the same size as Freestyle Libre 3, offering 15 days of life and compatibility with some of the latest AID (automatic insulin delivery) systems.
Common CGM Accuracy Issues and SolutionsMany people are side sleepers and wear sensors on the same side. When pressure is applied to the CGM sensors, they tend to provide incorrect readings due to the compression. This needs to be taken care of, you may try changing the side of the sensor or simply change the side you sleep.
Moreover, loose sensors may fail to provide accurate readings or fall off altogether. You may use hypoallergenic and waterproof CGM patches to keep your CGM sensor intact and in place during physical activities, including swimming.
How Accurate Are the Libre 3 SensorsThe FreeStyle Libre 3 sensor is highly accurate with a total Mean Absolute Relative Difference (MARD) of 7.9 which implies the sensor reads glucose values that are usually within 7.9% of lab reference values. More than 93% of the readings are in the range of ±20 mg/dL or ±20% of the reference values, which are higher than the FDA requirements of reliable treatment decisions. The accuracy is not affected by the 14 days of wear or dynamic glucose range, but it might be slightly higher (approximately 8.7-10% in children) with MARD.
MARD is substantiated by independent research to be 8.9-11.6% putting it on a par or even better levels compared to its competitors, such as Dexcom G7. In 2024, a recall was issued over certain lots (T60001948, T60001966, T60001969) due to the possibility of high readings; users are advised to check lots and get them replaced (free of charge) where necessary.
Is Your Faulty CGM Still Not Working Right?No worries! If your sensor is faulty or inaccurate, don’t throw it away. Abbott offers free sensor replacements at no extra cost. Complete a Freestyle Libre sensor support request form to claim your new sensor delivered to your doorstep.
Extra Value TipLog in to LibreView using the same credentials as your phone app. It provides insights such as:
A1c trends. Mealtime patterns. Daily glucose variations and trouble spots where the sensor struggled to capture data. Share Your DataWith the Libre LinkUp app, users can share real-time glucose data with family or healthcare providers. This feature also sends alerts for high or low readings, ensuring prompt action in emergencies. The picture below shows all the steps to share your data on Freestyle Libre 3 sensors. You may follow the same steps to share data on Libre 2 and Libre 2 Plus as well.
ConclusionWhile the FreeStyle Libre 3 sensor boasts high accuracy, occasional FreeStyle Libre 3 accuracy problems may arise due to initial sensor adjustment, user error, or faulty hardware. However, there are troubleshooting steps you may follow to get rid of these errors, and in case they persist, you may always fill out a form to claim your new sensor. The link to the Freestyle Libre Sensor Support Request form has been provided above. For reliable diabetic supplies, free deliveries (within the USA), easy re-ordering, and friendly customer support, visit CGM Monitors today!
Note: The FreeStyle Libre 3 sensor will no longer be ailable after September 2025. We recommend exploring alternative CGM options like Libre 3 Plus and Libre 2 Plus.