A composition for the treatment of skin comprises a carboxylated, acidic amino acid obtained by acidifying an acidic amino acid with a carboxylic acid. The resultant material, which is also referred to as a tricarboxylic acid or an amino fruit acid, has significant benefit for the treatment of a number of skin conditions. In addition, the composition of the present invention is very noncaustic to skin, even when employed at a pH as low as 0.5. Also disclosed herein are therapeutic methods and compositions which employ the carboxylated acidic amino acids.