Cosrx The Vitamin C 23 Serum is a highly concentrated treatment that fades acne scars and brightens the complexion to revitalize dull and dry skin. Targets dull and rough skin, dark spots and scars, uneven skin texture and fine lines and wrinkles. It provides a youthful-looking glow and diminishes signs of aging with 23% Vitamin C. This serum leaves skin brighter, smoother, and hydrated.