Image 1 of 1 Obagi-C Fx C-Clarifying Serum $132.00 Formulated with 4% Arbutin and 10% L-Ascorbic Acid to help minimize the appearance of skin aging for a brighter complexion. Quantity: Add To Cart Added! Formulated with 4% Arbutin and 10% L-Ascorbic Acid to help minimize the appearance of skin aging for a brighter complexion.