Wiki / Health
Libre 3
The FreeStyle Libre 3 is my go-to continuous glucose monitor (CGM) for managing Type 1 Diabetes. Made by Abbott, it's the most effective and consistent CGM I've used.
Real-world wear time: Usually lasts around 15 days for me. Sometimes requires an external patch over the sensor to get more life out of it, otherwise it can fall off.
How It Works
A small sensor with a thin filament sits just under the skin on the back of your upper arm. It continuously measures glucose in the interstitial fluid and sends readings to your phone via Bluetooth every minute.
- No fingerstick calibrations - Works out of the box
- 1-hour warm-up - Quick start after applying
- Real-time alerts - Customizable high/low alarms
- Urgent low alarm - Cannot be silenced (FDA requirement)
Specifications
- Official wear time: Up to 14 days
- Reading interval: Every minute
- Accuracy (MARD): ~7.8-7.9%
- Sensor size: 21mm diameter x 2.9mm height
- Bluetooth range: Up to 33 feet
- Water resistance: 1 meter for 30 minutes
- Approved ages: 4 and up
Why I Use It
After trying multiple CGM systems, the Libre 3 has been the most consistent for me. The readings are reliable, the app works well, and the small sensor is discreet.
The minute-by-minute data helps catch rapid changes, especially during exercise or after meals. Being able to see trends in real-time is a game changer for dosing decisions.
Adhesion Tip
The main issue is keeping it stuck. An external adhesive patch (like SkinGrip or Simpatch) placed over the sensor helps extend wear time past the 14-day mark. Without it, the edges can start peeling, especially if you're active or sweating.
Data & Sharing
- LibreView - Cloud platform for reports and sharing with doctors
- LibreLinkUp - Share readings with family/caregivers
- Stores 14 days - Syncs when phone comes back in range
- Watch idea - Plan to show glucose on a Garmin watch via LibreLinkUp (Developer Ideas)