The Cosrx The Niacinamide 15 Serum is a brightening and anti-wrinkle serum that contains 15% niacinamide. This lightweight serum absorbs quickly into the skin to help even out skin tone, reduce the appearance of fine lines and wrinkles, and brighten the skin. Additionally, it contains hyaluronic acid to help keep the skin hydrated. This serum is safe to use on all skin types.