Polyhydroxy acids (PHAs) – also called gluconolactone and lactobionic acid – can be described as a ‘kinder, gentler’ type of alpha hydroxy acids (AHAs) and have taken the skincare market by storm. AHAs are chemical peels designed to erase fine lines and give the skin a smoother appearance. The more concentrated the peel is, the more skin irritation can occur, which is the downside to AHAs. PHAs are more suitable for sensitive or dry skin. In addition to sloughing off dead skin cells, they also draw in moisture to help skin stay hydrated and help improve the skin’s ability to defend itself. If that in and of itself wasn’t a solid improvement over AHAs, it also is an anti-oxidant which can protect skin from UV rays. When combined with other ingredients, it can also lighten darker skin patches. In other combinations it can lessen inflammatory conditions like acne, rosacea, dermatitis, psoriasis and melasma.