Pyruvic and Tartaric Acid
Pyruvic and tartaric acid are not AHAs or BHAs. They live in categories all their own. Pyruvic acid is an alpha-keto-acid that is found often in photoaging peels. It's more powerful than glycolic acid and caters to acne-prone skin, but is known to help with skin texture, fine lines, and lightening hyperpigmentation. Tartaric acid is a PHA — polyhydroxy acid — and is found in some plants and wine. PHAs are milder than other acids, so they're gentler on the skin. Because this particular PHA is rich in antioxidants, it helps fight off free radicals and keeps the skin strong by fending off glycation. PHAs are larger molecules, so they don't penetrate as deeply as AHAS or BHAS.