About 18 months ago, Time magazine tagged alpha hydroxy acids “all the rage.” Since then, skin care products, from those found in dermatologists’ offices to estheticians’ chairs, and from department store cosmetics counters to supermarket toiletries aisles, have prominently featured this popular ingredient. Now they are popping up in nail care treatments, particularly for cuticle care. NAILS got to the bottom of what these acids are and what they do in nail services.

Alpha Hy-whatsy Acids?

Also known as AHAs, alpha hydroxy acids are derivatives of fruit, sugar, and milk. Each of these sources of AHAs creates a sub-type, so to speak, of alpha hydroxy acid. The AHAs created from fruit are malic, tanic, tartanic, or citric acids. AHA made from sugar cane is glycolic acid, and AHA made from milk is lactic acid.

When choosing AHA products, it is important to understand exactly what you are putting on the skin and how it works, whether you intend to apply them to the cuticles or to facial skin. Some AHA product formulations are more potent than others, I and some are too strong for the nail area. You need to read the list of ingredients to determine what kind of AHAs a product contains before you make a purchasing decision.

AHAs work by loosening the connection between dead skin cells and live ones. When the connection is loosened, surface cells exfoliate more quickly than they would naturally to expose fresh, youthful-looking skin.

Typically, glycolic AHAs are the most aggressive. According to Doug School, executive director of Chemical Awareness Training Service in Newport Beach, Calif., “more aggressive” means faster-acting, but faster does not necessarily mean better than less aggressive AHAs. Glycolic AHAs were used first in skin care products, and these treatments were very aggressive. They worked quickly but had some drawbacks; namely dry and pooling skin.

Fruit and lactic acids, on the other hand, tend to be less aggressive than glycolic AHAs. Lactic acid is noted for its sponge-like ability to draw moisture with it when it is absorbed into the skin, says Schoon. This action causes the skin to plump up, which is what makes skin wrinkles “iron out.” “Lactic acid works more slowly than other AHAs, but it does less damage.” says Schoon.

So What Do AHAs Have To Do With Nails?

Nail care products made with AHAs have to be tailored to the needs and characteristics of the finger area, which is different from skin on other parts of the body. AHAs on the fingers have the most intense effect on the cuticle and the nail matrix.

Most nail care products that contain AHAs are designed to work on the cuticle. A good AHA cuticle product will soften the cuticle so removing the excess skin is easy, but will do so without damaging the nail plate or matrix. The “but” part can happen when products are formulated with too much lactic or glycolic acid. Too much lactic acid can make the nails soft and prone to peeling; too much glycolic acid can damage the cuticle.

Schoon says that although less-aggressive formulas may not work as quickly as the stronger ones, the time difference is negligible. “The less aggressive AHA products might not work as last as others. A typical AHA product for cuticles might take a few more days, not weeks, for visible results than if one were to apply something more aggressive.” he explains.

Somewhere you might overlook the possibility of undesirable effects on nails of AHAs is when applying facial or body AHA products. Because these are sometimes inert aggressive than AHA products designed for nails, they can inadvertently get to the nail plate, cuticle or eventually the matrix, and potentially cause problems.

So how do you know if you are getting a good or bad product? Many AHA products are marketed and advertised as containing a certain percentage of AHAs. While this might seem like a good yardstick as to a product’s efficacy, it isn’t always the rule. The action of the product depends on the proportions of different AHAs the product incorporates. For example, a product with 7% glycolic acid and 3% lactic acid will be more aggressive than another with 3% glycolic acid and 7% lactic acid. Also, other ingredients in the product determine how aggressive it may be. “These things are acids; therefore they can be neutralized. I can take a product with a really high percentage of AHAs and neutralize it to the point where it could be applied many times a day with none of the adverse side effects (peeling, dryness) associated with AHAs,” says Schoon. Therefore, nail technicians should look carefully when purchasing or advising the purchase of AHA products. Buffers such as ammonium or sodium hydroxide neutralize AHAs.

Dr. Howard Murad, founder/CEO of Murad, Inc., and assistant clinical professor of dermatology at University of California at Los Angeles, explains that discerning the good AHA products from the bad by looking only at the list of ingredients is difficult. Murad suggests looking at the proportion of ingredients. The ingredients are listed in descending order of the amount in the product. Also, other ingredients such as vitamin E, sodium PCA, allantoin, and tocopheroyl are good earners for AHAs. “Use your good sense when judging all the ingredients in a particular product. You know what is good for moisturizing skin; those are what make good carriers,” says Murad.

Although AHAs have been used since the 1920s, it wasn’t until 1993 that they made their big splash as a major skin care product ingredient. The market is already growing, and manufacturers are attempting to expand the applications for AHAs as well as similar derivatives. The newest thing to hit the market are beta hydroxy acids, but Schoon predicts that they will find few, if any, applications in the nail industry. Watch for innovations with AHAs, as they are sure to come, but read carefully and ask many questions before you take the plunge, too.