Developed in the 1980s as a gentler alternative to alpha hydroxy acids (AHAs), PHAs offer effective exfoliation without the irritation often associated with AHAs. With their larger molecular structure, PHAs take longer to penetrate the skin, making them suitable for sensitive skin types and newcomers to hydroxy acids. Additionally, PHAs act as humectants, retaining moisture and enhancing the skin's natural barrier, unlike some other hydroxy acids that can increase susceptibility to sun damage. Their antioxidant and anti-inflammatory properties make them ideal for individuals with common skin conditions like rosacea.