Malic acid

Malic acid — (see also Alpha Hydroxy Acids (AHAs)) the third smallest AHA in terms of molecular size. Although it is used in numerous cosmetic products, particularly those indicating a “fruit acid” content and generally designed for anti-aging, unlike glycolic and lactic acids, its skin benefits have not been extensively studied. Some formulators consider it difficult to work with, particularly when compared to other AHAs, and it can be somewhat irritating. It is rarely used as the only AHA in a product. It is found naturally occurring in apples.