SkinCeuticals Serum 10 AOX+ is a dermatologist recommended introductory antioxidant serum specially formulated for sensitive and reactive skin types who are beginning their medical grade skincare journey. With a gentle 10% pure vitamin C concentration and a skin-calming formula, it delivers antioxidant protection without the irritation risk of higher-concentration serums. Gentle antioxidant defense: 10% L-ascorbic acid provides meaningful environmental protection suitable for sensitive and reactive skin Introductory vitamin C formulation: Ideal entry-level antioxidant serum for patients new to vitamin C or with low tolerance to higher potency formulas Anti aging skincare: Supports collagen synthesis and helps reduce the early appearance of fine lines Alcohol-free and fragrance-free: Minimizes irritation risk for sensitized or post-procedure skin Redness reduction: Calms and soothes reactive skin while delivering protective antioxidant benefits Recommended for patients with sensitive, reactive, or easily irritated skin who require the protective benefits of a vitamin C antioxidant serum with a lower risk of sensitization. An excellent starting point before stepping up to higher-concentration formulas such as C E Ferulic. Key Ingredients: 10% L-Ascorbic Acid (Vitamin C). Usage: Apply 4-5 drops to clean, dry skin each morning before moisturizer and sunscreen. Alcohol-free and fragrance-free.