L-Ascorbic Acid (Vitamin C)
비타민C (아스코르빈산)
ASCORBIC ACID
The most potent and evidence-backed form of Vitamin C, but also the most unstable — oxidizes rapidly in air and light, turning orange and losing efficacy. Must be formulated at pH 2.5–3.5 for skin penetration. Klairs and COSRX offer L-AA serums; requires careful storage and conflicts with high-pH ingredients. Best used AM with vitamin E and ferulic acid for stability.
Ingredient Interactions
A study of a specific topical solution found that 15% L-ascorbic acid plus 1% alpha-tocopherol provided greater experimental UV protection in pig skin than either antioxidant alone. The finding is formula- and concentration-specific, does not validate every separate-product combination, and does not replace sunscreen.
In a specific experimental formula containing 15% L-ascorbic acid, 1% alpha-tocopherol, and 0.5% ferulic acid, ferulic acid improved formula stability and photoprotection in a pig-skin model. This is formulation-specific evidence; it does not establish the same result for arbitrary products layered together, and antioxidants do not replace sunscreen.
Products containing L-Ascorbic Acid (Vitamin C)
Common formula companions
Ingredients frequently mapped in the same products as L-Ascorbic Acid (Vitamin C). This is a formula pattern, not a compatibility or safety claim.