Skinceuticals  Serum 20 AOX+, 1-Ounce Bottle
Formulated with AOX+ advanced antioxidant technology. Contains a precise combination of 20% L-ascorbic acid with ferulic Acids to help protect against environmental damage and help reduce visible signs of premature aging. Optimal for normal or oily skin. Note: L-ascorbic acid will oxidize and darken with time, but will remain effective.  May cause a slight tingling sensation.