Another great product from The Ordinary. This 10% Lactic Acid serum exfoliates cells on the surface of the skin by breaking down the material that holds skin cells together. It also holds water in the skin and helps to lighten discolourations. You apply this at night after cleansing and I noticed a difference in my skin the day after using this acid serum. Those with sensitive skin should apply a moisturiser afterwards as it can cause irritation. It's an absolute bargain at £5.80 and with all The Ordinary products - it works.