The Ordinary 100% L-Ascorbic Acid Powder Fine 325 Topical Powder Vitamin C - an effective antioxidant that brightens skin tone and reduces the appearance of signs of aging This formula - visibly targets the appearance of uneven skin tone - dullness and signs of aging and is formulated to be mixed with other treatments The format of this formula is a very fine-anhydrous L-Ascorbic Acid powder and therefore provides the most direct topical exposure of extremely high concentrations of Vitamin C. format - a very strong tingling but non-irritating sensation is expected for the first 1-2 weeks until the skin's tolerance to such high exposure increases If topical Vitamin C is used as part of skin care - EUK 134 or Niacinamide at alternative times (ideal in PM Otherwise - EUK 134 / Niacinamide - may affect the integrity of pure Vitamin C (L-Ascorbic Acid)