Advanced Intensive System For a complete brightening treatment Double White features a combination of Vit C Serum 11S (11% of the stable vitamin C derived), Azelaic 20 (20% Azelaic Acid) and Alpha Arbutin (5% ). This powerful blend helps reduce discoloration, evens out skin tone and protects skin's structure from free radicals. The DermShield TM additive allows the use of the cream without causing irritation.