Alpha Hydroxy Vs. Beta Hydroxy

Woman putting product on her face
Image Credit: Alliance/iStock/Getty Images

Alpha hydroxy and beta hydroxy acids are two active ingredients found in many over-the-counter skincare products. Known as "AHAs" and "BHAs," these ingredients have similar properties, according to cosmetics experts Paula Begoun on her website CosmeticsCop. Depending on your prevailing skin care concern--aging skin or acne--a product containing one of these hydroxy acids may give you better results.

Hydroxy Acids

AHAs and BHAs are organic acids, both of which are characterized by a carboxylic acid group and a hydroxyl group, explain the cosmetic scientists at AHAs may include lactic, citric and glycolic acids, among others. Salicylic acid is the primary BHA used in most over-the-counter cosmetics. Knowing the names of these AHAs and BHAs is important so you can recognize them in product labeling--and choose the skincare that's most appropriate for your needs.


AHAs gently exfoliate the top layer of dead skin cells, increasing the rate of cell turnover and allowing newer, healthier skin to emerge, explains Begoun. This characteristic of AHAs allows your skin to be smoother and can aid in reducing discoloration. Begoun notes on that glycolic and lactic acid are the two AHAs that are most effective--and that are supported by the most research. "Malic acid, citric acid, and tartaric acid may also be effective, but are less stable and less skin-friendly; there is little research showing that they have any benefit for skin," she says on her website. Alpha hydroxy products, which are most effective and safe when used at a concentration of between 5 percent and 15 percent, may also encourage collagen production.


BHAs also have exfoliating properties markedly similar to AHAs, Begoun states, and yield similar results. However, they also unclog pores and act as antibacterials and anti-inflammatories, helping skin "heal and repair itself," she says. Of interest is that salicylic acid is an aspirin derivative, which gives it its soothing properties. BHA, or salicyclic acid, is sold in consumer products, with concentrations ranging from 0.5 percent to 2 percent.

Which is Best? indicates that because BHAs are more soluble in oil than in water, they are often used in many nonprescription acne products. Having the ability to reach deeper into the pores, BHAs are more effective in reducing the plugs that cause lesions to form, so BHA skin care may be best for those battling pimples and blackheads. Skincare products containing AHAs are best if you simply want damaged, sun-weathered skin to appear more refreshed.


Using hydroxy acids can cause your skin to be more sensitive to the sun, increasing your risk for sunburn–and sun-weathered skin. The Mayo Clinic points to U.S. Food and Drug Administration intervention in 2002, in which manufacturers of AHA skin care were made to include this warning on product labeling. Begoun states that using sunscreen on a daily basis and avoiding intentional tanning is important when using AHA skincare products.

references & resources