Alpha-hydroxy acids (AHAs) such as glycolic acid and lactic acid have been used for many years by dermatologists at concentrations of 20% to 30% for facial peel procedures. More recently, AHAs have been added to OTC washes and moisturizers at concentrations of 4% to 6%. AHAs have been found to soften the stratum corneum, remove dead cells, and change free radicals on the skin. These products combine well with both topical comedolytics and topical antibiotics. They can be used as the daily facial cleanser or moisturizer before application of prescription medication. AHAs in the 20% to 30% strength help to improve discoloration and scarring. Mild benefit can also be seen at the 4% to 6% strength. As with all other topical products, irritation may be a problem, especially during the initial few weeks of usage. AHAs are sometimes used
alone in mild acne. Various products, though, add glycolic acid to SA formulations claiming an increase in the exfoliation benefits. A 2% lactic acid cream gel preparation has been reported to be effective in both inflammatory and non-inflammatory acne lesions compared to placebo (66).