Alpha Hydroxy Acid (AHA) is derived from fruit and milk sugars, and it is commonly used to improve sun damaged skin and reduce wrinkles and age spots. AHA is also known under the following names: glycolic acid, lactic acid, citric acid, α-hydroxyoctanoic acid, and α-hydroxydecanoic acid.
The safety of AHA’s was assessed by the Food and Drug Administration (FDA) in the USA who sponsored two studies on this chemical. The studies showed an association between AHA use by:
- an increase in both the number of sunburn cells on the skin, and
- UV induced redness
Studies by the cosmetics industry show that AHA increases skin sensitivity to UV radiation. The sensitivity is reversible, and skin regains its original sensitivity approximately a week after use of AHA is stopped. Of course, serious burns occurring on the skin increase the risk for skin cancers in the future.
The Cosmetic Ingredient Review (CIR) expert panel concluded that glycolic and lactic acid are safe for use in cosmetic products at concentrations of 10 percent, “when formulated to avoid increasing sun sensitivity or when directions for use include the daily use of sun protection.” ~ source