COSRX The Vitamin C 13 Serum (20ml) is a gentle, water-based serum formulated with 13% pure vitamin C to brighten and even out skin tone. It also contains tocotrienols (super vitamin E), hyaluronic acid, and allantoin to hydrate, soothe, and protect the skin. Suitable for daily use, it helps reduce dark spots, fine lines, and pore size, leaving the skin looking radiant and youthful .