What are HA’s? Hydroxy acids (HA’s) have been around for decades to clinically treat a range of skin conditions. The most common forms of hydroxy acids are α-hydroxy acids, β-hydroxy acids, polyhydroxy acids, and bionic acids (PHA with an additional sugar molecule attached to the PHA structure). They are found in over the counter skin care … More Importance of hydroxy acids in your skin care routine Series α-hydroxy acids: Glycolic Acid