Alpha and Beta Hydroxy Acids. What really is the difference?
How much do you know about some of the skin’s best allies for acne and antiaging? Alpha hydroxy acids used in skincare include glycolic acid, lactic acid, malic acid, citric acid and mandelic acid. Salicylic acid represents the only beta hydroxy acid used on the skin.
The common misconceptions are that the beta hydroxy salicylic acid is lipophilic (oil-loving) and meant for oily acne-prone skin, while the alpha hydroxy’s are hydrophilic (water-loving) and better for antiaging.
Many physicians still explain this incorrect generalization to patients when discussing hydroxy acids.
Skin Innovations physician contributor Dr. Desmer Destang has extensive experience with hydroxy acids, and teaches aesthetic physicians on the correct uses of active skin ingedients.
She explains that “the difference between alpha and beta hydroxy acids is based on chemistry – these acids have carboxylic and hydroxyl functional groups. The alpha’s have a separation of 1 carbon atom, while the betas have a 2-carbon separation’.
“Salicylic acid has an affinity for sebum and oils based on it’s chemical structure having an aromatic side chain that binds to oil. But, so does mandelic acid. This also explains why mandelic acid as an alpha hydroxy has such strong effects on oily and acne-prone skin although it is an alpha hydroxy acid.”
Both types of acids are wonderful for the skin, and work by loosening dead rough skin on the surface. Eventually this dead skin flakes off and peels, revealing new softer skin. Depending on your skin, and the concentration of the acid used, this peeling can be at a low microscopic level which you almost cannot see, or it can be large flakes of peeling. Either way, your skin is regenerating and renewing itself. The amount of regeneration seen, however, tends to be proportional to the amount of shedding that occurs.