The FreeStyle Libre 3 system is painless to apply1 and wear1 with a simple 1-piece applicator.
There is a small needle (sharp) in the applicator to insert the filament into the back of your upper arm so the sensor can monitor your glucose. The needle does not remain in your arm after application.
Applying and Removing Your FreeStyle Libre 3 Sensor
1Alva, S. Journal of Diabetes
Science and Technology (2025):
https://doi.org/10.1177/19322968251329364.