The FreeStyle Libre 3 is one of the easiest CGMs to set up. Here is the complete process from unboxing to your first glucose reading.
Download LibreLink First
Download the FreeStyle LibreLink app for iOS or Android. Create an Abbott account or log in if you already have one. This step must happen before sensor application because the app starts the warm-up clock.
Application Site
The Libre 3 is approved for the back of the upper arm only. Clean the area with an alcohol wipe. Let it dry for 30 seconds — moisture interferes with adhesion.
Apply the Sensor
- Remove the sensor applicator from the sealed pouch
- Do not remove the cap yet — first press the applicator against the back of your upper arm
- Press firmly and hold for 5 seconds
- Twist and pull the applicator off — the sensor stays on your skin
The Libre 3 applicator is simpler than older models. Most users describe it as painless — the needle retracts immediately.
Start the Sensor in LibreLink
Open LibreLink → Add Sensor → Start New Sensor. The app connects via Bluetooth automatically. The 60-minute warm-up begins. You will receive a notification when the first reading is available.
First Reading
After 60 minutes, your glucose reading appears with a trend arrow. No fingerstick calibration is needed.
Enable Alarms
In LibreLink → Alarms: enable Low Glucose Alert (set your threshold), High Glucose Alert (optional), and Signal Loss Alert. The Urgent Low alarm (55 mg/dL) is always active and cannot be disabled.
Share with Caregivers
Download LibreLinkUp for caregivers or parents. They will receive an invitation to follow your readings in real time from their own device.
Extending Adhesion for 14 Days
- Apply a Simpatch, Skin Tac, or Tegaderm over the sensor if you exercise heavily or swim frequently
- The Libre 3’s adhesive is strong, but extended water exposure can loosen edges
- Do not cover the top of the sensor (where data is transmitted) — only reinforce around the edges