Use of products containing ascorbic acid (Vitamin C) and salicylic acid (Aspirin) on the Sensor location may interfere with the Sensor glucose readings.  Taking ascorbic acid while wearing the Sensor may falsely raise the Sensor glucose readings.  Taking salicylic acid may slightly lower the Sensor glucose readings.  In either case, the level of inaccuracy depends on the amount of the interfering substance active in the body.