Alphahydroxyacetone (AHA) is used to even out and smooth the skin's surface. IUPAC name: 1-hydroxy-2-propanone Dihydroxyacetone (DHA) is a small sugar-type molecule which reacts with amino acids and the amino groups of the skin keratin, forming complex colored compounds. IUPAC name: 1,3-dihydroxy-2-propanone