Isdin isdinceutics flavo-c antioxidant serum… Isdin isdinceutics flavo-c antioxidant serum is an antiaging facial serum. Formulated with a powerful combination of antioxidants to combat photoaging. It also has vitamin C in its formulation that acts on the skin for 10 hours. Its high concentration of vitamin C neutralizes free radicals, stimulates collagen synthesis and protects against the effects of UV radiation. Makes skin more radiant, helps it regain its elasticity, deeply moisturizing skin to make it look visibly rejuvenated.