COSRX The Niacinamide 15 Serum

COSRX The Niacinamide 15 Serum is a high-strength niacinamide serum designed mainly for acne-prone, oily, and uneven-toned skin. 15% niacinamide — helps with excess oil, enlarged-looking pores, and post-acne marks. N-acetylglucosamine (NAG) — supports brightening and skin texture. Zinc PCA — helps with oil control. Can be useful for acne marks and uneven skin tone, but 15% is relatively strong and may irritate sensitive skin. How to use: Start once daily, preferably at night, after cleansing and before moisturizer. If your skin tolerates it well, you can increase frequency.