A freestyle libre 3 plus sensor replacement is needed roughly every 15 days, since the sensor is designed for a fixed wear cycle rather than indefinite use. Unlike the freestyle libre 3 plus sensor replacement process for the standard version, the Plus variant is built for slightly longer wear in many regions, though approved duration can vary by country regulation, so checking the package insert matters more than following generic advice online.
When replacing a sensor, rotating the arm used and avoiding scar tissue or recently used sites helps with both comfort and accuracy. Applying to clean, dry skin, avoiding lotion near the site, and pressing the applicator firmly for the full recommended time are the most common reasons a new sensor fails to read correctly.