Freestyle Libre Setup Step 4: Activate & Scan your CGM


This article provides an overview of how to activate and begin scanning your continuous glucose monitor (CGM).

How to activate your sensor:

  1. From your phone, open the LibreLink app
  2. Tap the “Scan New Sensor” button
  3. Hold the top of your phone up to your sensor for a few seconds. Your phone should vibrate when the scan is complete. Please note that some Android phones don't have a "scan now" button and the phone should be waved over the sensor anyway.

From here, it takes about 60 minutes for the sensor to connect to Levels app. You will not be able to scan and receive data during that time. Once the sensor is connected you will receive a notification in the LibreLink app. From that point forward, you can use the LibreLink app to scan your CGM, and the data from that scan will be reflected in the Levels app.

Important things to note after applying your sensor:

  • How often you should scan: We encourage you to read through the following article to get an understanding of how often you should scan your sensor: How often often should I scan my sensor?
  • Sensor Errors: During the first 12 hours of applying the sensor, the LibreLink app sometimes shows the following error message (or something similar): Glucose Reading Not Available. Try Scanning Again in x Hours. If you see this message, please follow the following troubleshooting steps in this article: Troubleshoot: Sensor Error "Reading Not Available - Scan Again in x Hours"
  • Extreme High/Low Readings: Within the first 48 hours of wearing the sensor, it's common to experience abnormally high/low readings. If you encounter this, please read the following article for support: Troubleshoot: Extreme High/Low Readings During First 48 Hours
  • Sensor Accuracy: It's common for people to compare their CGM readings against their finger stick to compare accuracy and notice that the values are different. This can be disconcerting, but the key thing to know is that variations in readings will occur and this is expected. You can learn more about this here: Sensor Accuracy - CGM vs Finger Prick Glucometer

Once you have activated and scanned your sensor, please proceed to Step 5 below:

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