Issue link: https://www.ascpskindeepdigital.com/i/1495571
New member benefit! Get the ASCP SkinPro app at ascpskincare.com/skinpro 39 INGREDIENT DECK Carboxylic Acids: Old Friends, New Phrase by Ella Cressman IF THERE'S ONE CONSTANT in the skin care industry, it's the certainty of change. Each year, there are new and renewed modalities, protocols, ingredients, and, often, there is new understanding. Though not new in practice, we are now welcoming a new phrase to the professional esthetic vocabulary: carboxylic acids. This group includes alpha hydroxy acids (AHAs), beta hydroxy acids (BHAs), polyhydroxy acids (PHAs), and essential fatty acids; they are important components for healthy skin and should be included in any skin care regimen. Carboxylic acids are a class of organic compound in which a carbon (C) atom is bonded to an oxygen (O) atom by a double bond and to a hydroxyl group (-OH). 1 Widely occurring in nature and especially important to skin health, there are many types of carboxylic acids, including hydroxy and essential fatty acids, which are familiar and important skin care staples. Each with unique properties, their in uence on histological function can result in healthy, youthful-looking skin. ALPHA AND BETA HYDROXY ACIDS In the 1970s, doctors Eugene Van Scott and Ruey Yu found hydroxy acids had an in uence on hyperkeratinization, with speci c e ects depending on the molecular position of the carboxyl group. While they initially found bene t for hyperkeratotic stratum corneum, stratum compactum, ichthyosis, dry skin, keratin, and follicular hyperkeratosis, it was later discovered that regular applications of AHAs and BHAs resulted in improved skin health. The visual improvement of ne lines and wrinkles was attributed to an increased biosynthesis of glycosaminoglycans, collagen, and improved quality of elastic bers. 2