PHA stands for Polyhydroxy Acids, which are a type of chemical exfoliant used in skincare products. PHAs work by exfoliating dead skin cells on the surface, resulting in a more even skin tone and texture, and also help skin-care ingredients penetrate deeper into the layers of your skin, thus boosting their efficacy. PHAs are similar to alpha hydroxy acids (AHAs) and beta hydroxy acids (BHAs), but they are considered their next-generation cousins. PHAs are larger molecules than AHAs and BHAs, which means they penetrate less deeply into the skin and are generally better tolerated by all skin types, even the most sensitive. PHAs are known for their keratolytic effect, which helps to get rid of dead skin cells that block pores and smooth your skins texture by dissolving intercellular bonds and stimulating skin cell renewal. PHAs are also hydrating and have anti-inflammatory properties, making them suitable for sensitive skin types that react to other chemical exfoliants.