After 1 Week, 92% Agree Skin Feels Soothed*; Instantly Reduces Excess Oil by 58%**; Reduced Blemishes in 1 Week***; Zone treat your face by applying Niacinamide Serum to areas prone to oiliness and breakouts. Follow with your favorite moisturizer where needed.; Layer with Kiehl's Hyaluronic Acid Serum to hydrate & rebalance skin’s moisture.; Layer with Kiehl's Glycolic Acid Serum to gently exfoliate & improve texture.