PHA vs AHA
PHA vs AHA — a comparison of two chemical exfoliants where polyhydroxy acids (PHAs) are larger, gentler molecules that exfoliate more superficially, and alpha hydroxy acids (AHAs) penetrate more readily for stronger resurfacing. PHAs are often chosen for sensitive skin, while AHAs deliver more noticeable smoothing.
Key points
- PHAs such as gluconolactone and lactobionic acid have larger molecules that stay closer to the surface, generally causing less irritation.
- AHAs like glycolic and lactic acid penetrate more easily and tend to offer more pronounced exfoliation and brightening.
- PHAs also have humectant and antioxidant properties and are often recommended for sensitive or reactive skin.
- Both exfoliants can increase sun sensitivity, so regular sunscreen use is recommended with either.
Frequently asked
Are PHAs gentler than AHAs?
Generally yes, because PHA molecules are larger and penetrate less, which usually makes them milder and a good option for sensitive skin.
Do PHAs work as well as AHAs?
PHAs exfoliate more gently and gradually, so AHAs often give faster, more noticeable results, while PHAs prioritize tolerability for reactive skin.
Related topics
This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.
