Viral brand COSRX's Advanced The Vitamin C 23 Serum deserves a spot in your skincare routine, targeting uneven skin tone, visible signs of aging and noticeable dullness. Harnessing carefully selected ingredients, the K-beauty-born formula strives to bring as much radiance to your base as possible. The likes of ascorbic acid, niacinamide and caffeine promote a bright look while helping to smooth the appearance of texture. Ideal for seasoned vitamin C users, the formula reveals an enviably illuminated finish.