What Are PHAs (Polyhydroxy Acids)?

Polyhydroxy acids are a type of chemical exfoliant related to alpha hydroxy acids (AHAs) like glycolic acid. They help loosen and remove dead skin cells to improve skin texture and brightness.

What makes PHAs unique is their larger molecular structure, which means they penetrate the skin more slowly and work primarily on the surface. Because of this, they tend to be much gentler than other exfoliating acids.

Common PHAs used in skincare include:

• gluconolactone

• lactobionic acid

• galactose derivatives

Why PHAs Are Popular in Professional Skincare

PHAs are often described as “next-generation exfoliating acids” because they provide resurfacing benefits with a lower risk of irritation.

Key benefits include:

Gentle Exfoliation

PHAs dissolve the bonds between dead skin cells, helping smooth rough texture and refine the skin’s surface.

Hydration Support

Unlike many exfoliating acids, PHAs also act as humectants, helping attract and retain moisture in the skin.

Improved Skin Clarity

Regular use can help improve the appearance of:

• dull skin

• uneven tone

• visible congestion

• rough texture

Suitable for Sensitive Skin

Because PHAs penetrate more slowly than AHAs or BHAs, they are often better tolerated by sensitive or easily irritated skin types.

A PHA Toner in Professional Treatments

The PHA Skin Refining Toner is an example of how PHAs are used in professional skincare formulations.

This type of toner helps:

• gently loosen buildup on the skin’s surface

• clarify pores and refine texture

• support smoother, brighter-looking skin

• maintain hydration and barrier comfort

Formulas like this often combine gluconolactone and lactobionic acid, two widely used PHAs that promote gentle exfoliation while helping the skin retain moisture.

Because of their mild nature, PHA toners are commonly used in:

• hydration facials

• clarifying treatments

• professional back-bar protocols

Why PHAs Work Well in Hydration Facials

PHAs are particularly useful in hydration-focused treatments because they provide light resurfacing without stripping the skin.

Benefits in facial protocols include:

• removing surface buildup that blocks hydration

• improving absorption of serums and masks

• maintaining moisture balance during exfoliation

This makes PHAs a great alternative to stronger acids when the goal is smooth, hydrated, comfortable skin rather than aggressive resurfacing.

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