Carboxylic Acids: Old Friends, New Phrase

In this Skin Deep feature, I take a deep dive into the chemistry and clinical relevance of carboxylic acids—an umbrella term that includes well-loved ingredients like AHAs, BHAs, PHAs, and essential fatty acids. From exfoliation and hydration to barrier repair and anti-aging benefits, these compounds are foundational to skin health. This article unpacks their structure, function, and evolving role in skincare, proving that sometimes a “new” trend is just a trusted old friend in fresh terminology.