Polyhydroxy Acids · Gentle

PHA Exfoliants

Large-molecule exfoliants with humectant properties, well suited to sensitive skin

Ingredients

Mechanism of Action

How It Works

Polyhydroxy acids function similarly to AHAs, but their larger molecular size means they penetrate the skin more slowly, producing gentler exfoliation with less risk of irritation. They also attract water, giving them a dual exfoliant-and-humectant effect. PHAs are effective at slightly higher pH ranges than AHAs, which reduces their potential to disrupt the skin barrier. They are well tolerated by rosacea-prone, eczema-prone, and post-procedure skin.

Best For

Sensitive and reactive skin
Rosacea or eczema-prone skin
First-time exfoliant users
Post-procedure or compromised barrier

Watch Out For

Less potent than AHAs; visible results take longer to appear
Still increases photosensitivity; daily SPF is required
May not be sufficient on their own for significant textural concerns

What to Look For

Key Ingredients

Tap an ingredient to learn more

Gluconolactone

A gentle exfoliant with antioxidant and humectant properties

Lactobionic Acid

A large-molecule PHA that exfoliates while attracting moisture

How to Use

Routine & Layering

Best used AM & PM

PHAs can be used once or twice daily depending on the product and skin tolerance. Apply after cleansing and before serums. Because they are gentler and have a humectant effect, they can be used morning and evening without the drying potential of stronger AHAs.

AM Routine

Morning use is suitable for PHAs, particularly in toner or essence form. Follow with SPF, as all exfoliants increase sun sensitivity to some degree.

PM Routine

Evening use is well suited to PHAs in leave-on formulations. They can be combined with soothing or hydrating serums without risk of interaction.

Layering Order

1 Cleanser
2 PHA toner or serum
3 Hydrating serum or essence
4 Moisturiser
5 SPF (AM only)

Compatibility

Pairings & Interactions

Pairs Well With

Hydrating & Barrier Support

PHAs already have humectant properties, making them naturally compatible with hydrating serums and moisturisers

Anti-Inflammatory & Calming

Calming actives and PHAs are an ideal combination for reactive or rosacea-prone skin

Brightening & Depigmentation

Gentle exfoliation from PHAs supports the action of brightening actives by keeping cell turnover regular

Avoid Combining With

AHA Exfoliants

Stacking AHAs and PHAs in the same step is redundant and can cause unnecessary exfoliation; choose one

Got Questions?

Frequently Asked Questions

Are PHAs actually effective, or are they just a milder AHA?

PHAs deliver real exfoliation, just at a slower and gentler pace than AHAs. For someone with sensitive or reactive skin who cannot tolerate glycolic or lactic acid, PHAs can produce meaningful improvements in texture and tone over time. They are not a compromise but a genuinely appropriate choice for the right skin type.

Can I use a PHA if I have rosacea?

PHAs are among the few exfoliants suitable for rosacea-prone skin. Their gentleness and anti-inflammatory properties make them far less likely to trigger flares than AHAs or BHAs. That said, individual triggers vary, and patch testing before full-face application is always sensible.

How long will it take to see results with a PHA?

Because PHAs work more gradually than AHAs, expect to use them consistently for 6 to 8 weeks before noticing significant textural improvements. Tone and radiance often improve first, followed by more gradual softening of uneven texture.

Can I use a PHA every day?

Many people tolerate daily PHA use without issue, particularly at lower concentrations. Start with once daily and monitor for any signs of irritation before increasing frequency.

Is a PHA suitable after cosmetic procedures?

PHAs are one of the most commonly recommended post-procedure exfoliants because of their gentleness and barrier-friendly properties. After treatments such as microneedling, peels, or laser, they can help maintain cell turnover without disrupting the recovery process. Always follow your clinician's specific guidance on timing.

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