Do not ignore symptoms that may be due to low or high blood glucose. If you have symptoms that do not match the Sensor glucose reading or suspect that your reading may be inaccurate, check the reading by conducting a finger stick test using a blood glucose meter. If you are experiencing symptoms that are not consistent with your glucose readings, consult your health care professional.

What substances could interfere with the results generated by the FreeStyle Libre system?

You can take standard doses of ascorbic acid (vitamin C) and still make treatment decisions with the Sensor. Taking higher than the maximum recommended daily allowance (RDA) of ascorbic acid may affect the Sensor readings and make them look higher than they really are.1

Reference

1. FreeStyle Libre flash glucose monitoring system User's Manual.