What Is AHA in Skin Care?

AHA, or alpha hydroxy acid, is a skin care product ingredient made from fruit, milk or sugar cane. The makers of products with AHA promote its ability to reduce the signs of ageing and to improve acne.

Lactic (from milk), glycolic (from sugar cane) and citric acids (from oranges and lemons) are the most commonly used AHAs. AHAs have some side effects that make them inappropriate for many people.

How AHA Works

AHAs penetrate the dead surface cells of the skin, loosening the molecular bonds that attach them to the underlying tissues. The loose cells slough off, exposing newer skin.

Most of the skin care products with AHA have it in concentrations of between 5 and 8 per cent. Lower concentrations are ineffective and higher ones can increase the severity of AHA's potential side effects.

Products with AHA concentrations of between 40 and 70 per cent are reserved for professional skin peels, according to the Johns Hopkins Cosmetics Center,

AHA Side Effects

AHA's two most common side effects are increased sun sensitivity and skin irritation. Over a course of 12 years, between 1992 and the introduction of AHAs in skin care products, and 2004, the FDA received 114 complaints about side effects.

Those complaints included a number of problems like burning and blistering, rashes, itching, swelling and tenderness. Some people reported more severe sunburns after using AHA.

The FDA says that the number of side effect complaints has dropped off dramatically since 2004, and the complaints they do get are usually associated with the more potent AHA products used as skin peelers.

AHA Research

2002 research at the FDA and Brookhaven National Laboratory followed the skin of Caucasian men treated with 10 per cent glycolic acid AHA for 4 weeks. They developed an 18 per cent increase in sensitivity to UV light. Exposure to the sun's UV rays has been linked to skin ageing and cancer.

The researchers also found, however, that within a week after they stopping the AHA, the men's skin returned to its normal sensitivity. If you use an AHA product and notice your skin burning more easily, simply stop using it. There won't be any long-term effects.

AHA Skin Peels

Johns Hopkins says that skin peels containing glycolic acid can diminish facial lines, remove skin sallowness and uneven pigmentation, smooth skin texture and remove acne.

If you have a professional skin peel, expect an initial series of treatments until you get the desired results. These treatments will be spaced about 2 weeks apart. After the initial set, peels every 6 months or so will maintain your results.

Using Commerical AHA Products

The University of Maryland Medical Center recommends 8 per cent AHA over-the-counter products for home use. If you need something stronger, your dermatologist can prescribe 12 per cent products.

While you can purchase AHA products at as high as 60 per cent concentrations online, you'll use them at your own risk.

Even at 8 per cent concentrations, AHA products will raise your UV sensitivity. Always use adequate sun protection while using products with AHA. Keep your skin covered or protected with sunscreen.