Alpha Hydroxy Acids for Skin Care

by Food and Drug Administration (FDA)

Baby boomers and others who once sought the sun's rays with little thought of skin damage are now paying the price — billions of dollars annually for cosmetics containing alpha hydroxy acids (AHAs). Derived from fruit and milk sugars and served up in creams and lotions, AHAs attract customers with their supposed ability to reduce wrinkles, spots, and other signs of aging, sun-damaged skin. Some scientific evidence suggests they may work.

But are these products safe? Since 1989, the Food and Drug Administration has received more than 100 reports of adverse reactions in people using AHA products. Their complaints included severe redness, swelling (especially in the area of the eyes), burning, blistering, bleeding, rash, itching, and skin discoloration.

FDA believes reactions from AHAs are probably even more widespread. Past experience suggests that for every adverse reaction report the agency receives, the manufacturer receives 50 to 100. "This would translate into approximately 10,000 adverse reactions being received for AHA-containing products," says John Bailey, Ph.D., acting director of FDA's Office of Cosmetics and Colors.

Also, their relative newness (they've been widely available only since about 1992) means that their long-term effects are unknown. An industry-sponsored study found that people who use AHA products have greater sensitivity to sun, raising the specter of greater risk of photoaging and skin cancer.

"There are many unanswered questions in front of us," Bailey says. "AHAs are unlike anything else ever introduced onto the cosmetic market on such a wide scale. They are not your traditional cosmetics."

In spring 1997, the National Toxicology Program of the National Institute of Environmental Science accepted FDA's proposal to study AHA safety. While FDA awaits the results, expected by the year 2000, the agency is cautioning consumers to take extra care with AHA products: for example, avoiding the sun when possible, otherwise using adequate sun protection, and reporting adverse reactions immediately to doctors or FDA directly.

"These are very, very popular products," Bailey says. "Very little about the process restricts their sale. And it's a somewhat alarming idea to put acids on the skin. It raises obvious safety questions."

AHAs Are Everywhere

AHA cosmetics are believed to have derived from the "chemical peels" that dermatologists and plastic surgeons have used for years. The peels, typically trichloroacetic acid, phenol, resorcinol, and salicylic acid, help remove undesirable signs of skin aging, such as discoloration, roughness and wrinkling. The chemicals cause the skin to lose its outer layer, or peel off, revealing a fresher-looking layer of skin. Known as chemical exfoliation, the procedure is done in doctors' offices so that doctors can control the process and prevent deep skin burns from the highly acidic solutions.

Cosmetic manufacturers began to market similar but milder versions of these chemical peels containing AHAs for salon and at-home use around 1989. They quickly caught on, and by 1992, mass marketing had begun. Today, says Lisa Berger, a cosmetic sales manager for a Hecht Co. department store in Washington, D.C., "every [cosmetic company] has AHA products. There used to be only three product lines; now there are 20."

The AHAs used most often in cosmetics are glycolic acid and lactic acid, although there are others, and many are used in combination. Increasingly, says Zoe Draelos, M.D., a dermatologist in High Point, N.C., manufacturers are using poly-AHAs, which have larger molecules, and ingredients such as salicylic acid. According to Draelos, who consults for several large U.S. cosmetic companies, these products may produce less skin irritation.

Typically, AHA products sold to consumers have an AHA concentration of 10 percent or less. The concentration of AHA products used by trained cosmetologists may run between 20 and 30 percent, while those used by doctors can range from 50 to 70 percent.

Though sold to consumers mainly in face and body creams and lotions, AHAs also can be found to a lesser degree in other cosmetics, such as shampoos and cuticle softeners. Available everywhere, from discount pharmacies to fine department stores, the products typically range in price from a few dollars to as much as $60 a bottle.

Product Status

Some in the cosmetic industry have suggested that AHA products are more than simple cosmetics, coining the term "cosmeceutical" to describe them instead.

Under the 1938 Federal Food, Drug, and Cosmetic Act, cosmetics are defined as "articles intended to be rubbed, poured, sprinkled, or sprayed on, introduced into, or otherwise applied to the human body or any part thereof for cleansing, beautifying, promoting attractiveness, or altering the appearance." Drugs are defined as products intended for treating or preventing disease and affecting the structure or any function of the body. They are subject to premarket review and approval; cosmetics are not.

"The term 'cosmeceutical' is not recognized by law," Bailey says. "These products, depending on their intended use, would be regulated either as cosmetics, drugs, or both as cosmetics and drugs."

FDA has a particular concern about AHAs because, unlike traditional cosmetics, AHAs seem capable of penetrating the skin barrier. In reviewing the limited data on AHAs, FDA concluded in a 1996 report that certain formulations of AHA products can affect the skin in a manner similar to that of chemical peels — that is, increasing cell turnover rate and decreasing the thickness of the outer skin. The effect depends on the product's pH level (a measure of its acidity), the AHA concentration, and the AHA vehicle cream, as well as how the product is used (for example, frequency of use and where on the skin it is applied).

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.