COSRX The Niacinamide 15 Serum is a high-strength niacinamide serum designed to target stubborn acne, excess oil and enlarged pores. Powered by 15% niacinamide with acetyl glucosamine and zinc PCA, this K-beauty pore-minimizing serum controls and balances sebum, refines rough skin texture and helps fade post-acne marks. The lightweight, fluid texture sinks in quickly without any greasy residue, delivering gentle daily exfoliation while keeping skin calm and comfortable. Ideal for oily and acne-prone skin, it leaves the complexion smoother, clearer and more evenly toned with every use.