Chemical exfoliants can make skin feel smoother and look brighter, but strong acids may sting or irritate. Polyhydroxy acids (PHAs) are often described as a gentler option. This guide explains what PHAs are, how they compare with other acids, and how to use them. It is general information, not medical advice.
What PHAs are
Polyhydroxy acids are a group of exfoliating acids related to alpha hydroxy acids (AHAs). Common PHAs include:
- gluconolactone,
- lactobionic acid.
They loosen the bonds between dead skin cells on the surface, helping them shed.
How PHAs compare with AHAs
- Glycolic acid is a small molecule that exfoliates effectively but is more likely to sting.
- Lactic acid is slightly larger and often milder than glycolic acid.
- PHAs are larger molecules, which is thought to make them work more slowly near the surface. Many people with sensitive skin find them more comfortable.
PHAs also have humectant properties, which can help with hydration.
Who might prefer PHAs
- People with sensitive or reactive skin.
- Beginners to chemical exfoliation.
- Those who found glycolic acid too strong.
People with rosacea, eczema, or other skin conditions should check with a dermatologist before using any exfoliant.
How to use a PHA toner
- Cleanse and dry your face.
- Apply the toner with your hands or a cotton pad.
- Follow with serum and moisturizer.
- Start two or three times a week, then increase if your skin is comfortable.
Avoid using several exfoliants in the same routine. If you use a retinoid, alternate nights.
Sun protection
Exfoliating acids can increase sun sensitivity. Use a broad-spectrum sunscreen every morning.
Signs of over-exfoliation
- Stinging when applying normal products.
- Redness or tightness.
- Shiny, raw-looking skin.
- New flaking.
If you notice these, stop exfoliating and use a gentle cleanser and moisturizer until your skin settles.
Reading the label
- Look for gluconolactone or lactobionic acid.
- Check for fragrance or alcohol if you are sensitive.
- Note any added AHAs or BHAs.
- Follow the brand's usage directions.
Quick checklist
- Choose a PHA if stronger acids irritate you.
- Start slowly, a few times a week.
- Do not layer multiple exfoliants.
- Use sunscreen daily.
- Stop if you see signs of over-exfoliation.
FAQ
Are PHAs effective? They exfoliate more gently, so results may be gradual. Many people value them for comfort.
Can I use PHAs every day? Some people can. Start slowly and increase only if your skin tolerates it.
Can PHAs help with acne? They can help with texture, but BHAs like salicylic acid are more often used for clogged pores.
