Alpha and Beta Hydroxyl Acids are key ingredients used in skin care formulas for purposes of peeling or exfoliating the skin. Alpha hydroxyl acids or AHAs are also referred to as fruit acids because they are primarily derived from citrus fruits, grapes and apples. AHAs may also be obtained from milk, corn and sugarcane. They share a common chemical structure that consists of a hydroxyl group on the alpha carbon position. Examples include lactic acid, malic acid, glycolic acid and citric acid.
Beta hydroxyl acids or BHAs on the other hand have a chemical structure that is a little different and less commonly used. The key beta hydroxy acid used in skin care products is salicylic acid. However, you should also check the product label for tropic acid, trethocanic acid or beta hydroxybutanoic acid.
The key difference between AHAs and BHAs is that alpha hydroxy acids are water soluble, while the beta hydroxy acids are oil soluble. Both are increasingly used in skin care products including toners, cleansers, sunscreen and moisturizers.
Skin care product manufacturers claim that alpha and beta hydroxy acids offer benefits such as improved acne, eliminating sun damage, tightening and moisturizing the skin, diminished excess pigmentation spots, reducing the appearance of wrinkles, as well as improving underlying collagen and elastic skin tissues.
AHAs are effective in decreasing the strength of cell-to-cell bonding, such that the outer dead skin layer, the stratum corneum is able to peel off in sheets. BHAs are ideal for use in exfoliation, as well as improving skin tone.