Applications of Alpha Hydroxy Acids in Cosmetics: A Literature Review

Alpha-hydroxy acids (AHAs), including glycolic acid and lactobionic acid, are widely used in the treatment of various facial dermatoses. Over the past decade, these compounds have been increasingly incorporated as active ingredients in daily skincare cosmetics. This review synthesizes current knowledge on the efficacy, mechanisms, and safety of AHAs, as well as the relevant regulatory guidelines and formulation strategies. Accordingly, this review seeks to provide a comprehensive overview of AHA applications, offering valuable insights for researchers and formulators in the cosmetic industry. Kallikrein-related peptidases (e.g. KLK5 and KLK7) can degrade calcium-dependent adhesion proteins between corneocytes, including desmoglein (DSG), desmocollin (DSC) and corneodesmosin(CDSN). This leads to desmosomal degradation, reduced keratinocyte adhesion, and accelerated skin corneocyte shedding, thereby alleviating follicular keratinization. In additon, SPINK5 and LEKTI can act as KLKs' inhibitor. However, external use of products containing AHAs can promote the expression of KLK7, thereby promoting exfoliation of the keratin.