PHA: The Acid With Better Skin Benefits

Polyhydroxy acids are the new superstars of over-the-counter chemical exfoliants. They’re milder than their alpha-hydroxy acid cousins, gentle enough for sensitive skin, and nourish and protect in ways other acids do not.

- KAYCE TEO

Polyhydroxy acids (PHAs) are having a major skincare moment. Considered second-generation alphahydroxy acids (AHAs), PHAs work in a similar way. They break down and remove the ‘glue’ that binds dead cells to the skin surface, revealing a brighter, plumper and smoother complexion. AHAs, beta-hydroxy acids (BHAs) and PHAs form the triumvirate of chemical skin exfoliants.

THE GENTLER EXFOLIANT

The most common PHAs are gluconolactone, galactose and lactobionic acid. As they have larger molecules than AHAs, they can’t penetrate skin as deeply, so their work is confined to the top layer, sloughing away dull, dead cells as slower-acting but equally effective exfoliants. If you find AHAs too harsh, PHAs might work for you – they are clinically proven to be suitable for sensitive skin.

PHAs are actually not that new. Clinical studies from as far back as 2004 have detailed their use in treating photodamaged skin. Says dermatologist Dr Teo Wan Lin: “PHAs seem novel because the term ‘polyhydroxy acid’ hasn’t been used frequently in recent times, although our knowledge of it stems from the 1970s.”

The reason we’ve seen a slew of PHA products in recent months is down to business. The patent on PHAs recently expired, so the cost of using it as an ingredient in skincare products has been drastically lowered.