Ascorbic Acid (10 Ppm)
Ascorbic acid, also known as Vitamin C or L-ascorbic acid, is the primary water-soluble antioxidant found in skin tissue. It is used in concentrations typically between 5–20% in skincare formulations. It is extremely unstable and oxidizes easily in the presence of light or air, requiring a pH below 3.5 in water-based formulas or a waterless formulation to remain stable. Its CAS number is 50-81-7 / 62624-30-0.
Ascorbic acid boosts the skin's own collagen production, helping to reduce wrinkles and improve skin firmness. It inhibits the enzyme tyrosinase to fade hyperpigmentation and brown spots. When used under sunscreen, it enhances UV protection, especially when combined with Vitamin E and ferulic acid.
High concentrations (above 10%) may cause tingling or irritation, particularly in sensitive or rosacea-prone skin. The ingredient is extremely unstable and oxidizes rapidly when exposed to light or air; water-based formulas require a pH below 3.5 for stability and skin penetration. Should be used under sunscreen, not as a replacement for it.
