Kiehl's Retinol Skin-Renewing Daily Micro-Dose Serum is a luxurious, non-irritating, and fast-absorbing retinol serum that helps to renew skin cell turnover, reduce the appearance of fine lines and wrinkles, and enhance skin radiance. With 0.5% retinol, this formula provides a gentle yet effective dose of retinoid, which is encapsulated in a nano-particle delivery system to minimize irritation while maximizing results. It can be used daily as part of a skincare routine for smoother, brighter, and more youthful-looking skin.