What You Should Know About AHAs

Things to know when shopping for a low-priced alpha hydroxy acid product:

* AHAs generally cause less skin irritation than prescription Retin-A products. Still, stinging may occur. And some users report an increase in blemishes for the first few weeks as impurities are brought to the surface.

* Drugstore cosmeticians (see Directory, E4) can offer additional information on products and help consumers choose the best items for their skin types.

* People with sensitive skin should consider face products with the minimal 4% concentration.

* Contents are listed in decreasing order of concentration. Look for a product that has a fruit acid as one of the top four ingredients, manufacturers suggest.

* The concentration isn’t always clearly stated on packaging. Some companies offer the information through their consumer hot lines; others don’t. Says a L’Oreal spokeswoman: “We don’t talk about percentages.”

* A product’s overall effectiveness may hinge on non-AHA ingredients as well as on its pH level.

* Some products contain ingredients that may be mistaken for AHAs. The Revlon Results line, for example, contains a neutral, not acidic, molecule. Product literature says it offers the benefits of AHAs without the stinging.