Alpha-hydroxy acids are used as a topical treatment for wrinkles. Alpha-hydroxy acids (AHAs) are compounds found in food products. Glycolic acid comes from sugar cane, lactic acid from milk, malic acid from apples, citric acid from citrus fruits, and tartaric acid from grapes and bananas. When applied to the skin, these acids remove dead cells from the surface of the skin. The removal of dead skin cells reduces the appearance of wrinkles. The alpha-hydroxy acids are all contained in various skin care products, but glycolic acid and lactic acid are most commonly used because they are able to penetrate the skin to the greatest degree.
Alpha-hydroxy acids are exfoliants. They reduce cell adhesion. When applied to the skin, they cause the dead cells to loosen and slough away. This allows new skin to grow. Research suggests that alpha-hydroxy acids may increase the production of collagen and elastin in the skin. Daily application of alpha-hydroxy acids improves wrinkles, smooths the skin, and evens out pigmentation. Skin care products with a 5 to 8% concentration of alpha-hydroxy acid and a pH of 3 or 4 are most effective at improving the appearance of the skin. Alpha-hydroxy acids can improve the effects of aging and sun damage.
Alpha-hydroxyl acids for use at home are available in over the counter products and by prescription. These products are available in gels, creams, toners, and lotions. Creams and lotions contain more moisturizers than do gels and toners. According FDA regulations, the concentration of the alpha-hydroxy acid in products available without a prescription must be less than a 10%. A 10% concentration is high enough to cause exfoliation but not high enough to increase the production of collagen. The effectiveness of a product containing alpha-hydroxy acid also depends on the pH level of the product. Products with a high pH level are less acidic and are, therefore, less irritating to the skin. A high pH level also reduces the efficacy of the product in decreasing the appearance of wrinkles. A type of formulation (gel, toner, lotion, or cream) may be more or less effective on certain skin types. For example, those with oily skin may find that a gel or toner is more effective than creams or lotions.
Alpha-hydroxy acids have side effects. Irritation may result from the use of alpha-hydroxy acid. Irritation may be exhibited as redness, burning, stinging, itching, pain, blistering, and scarring. Skin discoloration has been reported with the use of alpha-hydroxy acids. Darker skin is more prone than lighter skin to scarring from alpha-hydroxy acids. Because alpha-hydroxy acids remove the top layer of skin, they increase the skin’s sensitivity to sunlight. Individuals using these products should use a sunscreen. Products with higher concentrations of alpha-hydroxy acid are more likely to cause adverse reactions than products with lower concentrations. Products with alpha-hydroxy acids should not be used to excess. Excessive use can cause skin damage. Only one product containing alpha-hydroxy acid should be used. Products should not be combined. Other products that promote exfoliation, such as facial scrubs or loofahs, should not be used in conjunction with alpha-hydroxy acid containing products.