AHA + PHA
AHA + PHA — a pairing of alpha-hydroxy acids with polyhydroxy acids, a gentler class of exfoliating acids with larger molecules. AHAs deliver more noticeable surface exfoliation, while PHAs exfoliate more mildly and also offer humectant, water-binding properties. Together they can provide balanced exfoliation that may be better tolerated by sensitive skin.
Key points
- PHAs such as gluconolactone and lactobionic acid have larger molecules that penetrate more slowly and gently than AHAs.
- AHAs provide stronger surface resurfacing to address dullness and uneven texture.
- PHAs are often described as suitable for sensitive skin and can also help attract moisture.
- Pairing the two can moderate the intensity of exfoliation while still improving skin smoothness.
- Sunscreen remains important, as exfoliating acids can increase sun sensitivity.
Frequently asked
What is the difference between AHA and PHA?
PHAs are chemically similar to AHAs but have larger molecular sizes, so they exfoliate more gently and are often better tolerated by sensitive skin. PHAs also have humectant properties that help bind water to the skin.
Is an AHA and PHA combination good for sensitive skin?
This pairing can be a good middle ground, since the PHA softens the overall intensity while still supporting exfoliation. Patch testing and gradual introduction are still recommended.
Related topics
This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.
