a cosmeceutical skin care brand from the United States created by plastic surgeon Barry Cohen. The product range contains high levels of glycolic acid (according to the brand it contains the highest level available at retail) which means more active ingredients are able to penetrate the skin. Glycolic acid is used in cosmetics as an exfoliant, to diminish pigmentation and help stimulate the production of collagen. According to the brand, products containing the ingredient are more effective when paired with a certain pH level, hence the brand name. The product range includes an anti-ageing line, skin care basics such as cleansers and moisturisers, and booster products such as a vitamin C serum, to enhance the efficacy of certain products.