Alpha hydroxy acids

1 - INTRODUCTION AND CLASSIFICATION

Hydroxy acids (HA) are a chemical greoup which has been used for decades to treat a variety of skin conditions including anti-wrinkling benefits, radical-scavenging effects and treatment of several hyperpigmentation disorders. They are broadly divided into alpha hydroxy acids (AHA), beta hydroxy acids, polyhydroxy acids and bionic acids.

AHA, also known as “fruit acids”, are naturally found in foods but the majority of them are now chemically produced. Structurally, AHA contain a hydrocarbon chain of varying length, with a carboxyl end group followed by a hydroxyl group attached to the next carbon atom. The linear nature of AHA structure makes them water soluble. Since AHA are extremely hydrophilic they are unable to act optimally in the oily areas of face unless the face has been thoroughly degreased. The smallest and most widely used in the AHA group is glycolic acid (GA). Other group members include lactic acid, malic acid, mandelic, tartaric acid and citric acid.