COSRX The Niacinamide 15 Serum 20ml is a lightweight, high-concentration serum formulated to improve skin clarity and overall texture. Enriched with 15% niacinamide, it helps reduce the appearance of pores, regulate oil production, and brighten dull skin. Ideal for sensitive and blemish-prone skin, this serum penetrates quickly to deliver visible results, leaving your skin smooth, luminous, and balanced.