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Exfoliating acids

Gluconolactone (PHA)

Also listed as polyhydroxy acid, PHA

A polyhydroxy acid: a large, gentle exfoliant that also holds water. Suits skin that can't tolerate glycolic acid; the evidence base is small.

Limited evidence

What it is

Gluconolactone is a polyhydroxy acid (PHA) derived from glucose. Its larger molecule enters skin slowly, so it exfoliates more gently than glycolic acid, and its many hydroxyl groups make it a humectant. It is also an antioxidant.

PHAs are pitched for sensitive or rosacea-prone skin and for pairing with retinoids. The rationale is sound; the supporting studies are few and small.

How strong is the evidence?

Limited evidence

A double-blind trial in 150 people found 14% gluconolactone lotion and 5% benzoyl peroxide both reduced acne lesions versus vehicle, with fewer side effects from gluconolactone. Other reports describe smoothing and anti-aging benefits and good tolerance on sensitive skin, but independent replication is limited.

What it's used for, checked

Gentle exfoliation for sensitive skin

Mixed

Reported to be well tolerated on rosacea- and eczema-prone skin; few controlled comparisons.

Acne

Mixed

One 1992 trial found benefit versus vehicle with fewer side effects than benzoyl peroxide; little follow-up since.

Hydration

Holds up

A humectant: it binds water in the outer layer.

Who should be careful

  • Mild, but can still sting on broken or freshly exfoliated skin.
  • Use sunscreen, as with any exfoliant.

The studies

Every citation is checked against its PubMed record.

  1. A comparative study of gluconolactone versus benzoyl peroxide in the treatment of acne.
    Hunt MJ, Barnetson RS · Australasian Journal of Dermatology · 1992 · RCT

    In a double-blind trial of 150 people with mild to moderate acne, 14% gluconolactone and 5% benzoyl peroxide both reduced inflamed and non-inflamed lesions versus vehicle; gluconolactone caused fewer side effects.

  2. The use of polyhydroxy acids (PHAs) in photoaged skin.
    Grimes PE, Green BA, Wildnauer RH, Edison BL · Cutis · 2004 · Review

    Reviews polyhydroxy acids such as gluconolactone, reporting AHA-like smoothing and anti-aging effects with less stinging, added humectant properties, and compatibility with sensitive skin, rosacea and use after procedures.