You're About to See PHAs Everywhere — Here's What You Need to Know

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Just when you think you know all there is to know about skin care, another newbie arrives. Although many of these "new" ingredients aren't actually new, they're certainly having a moment in the skincare world. The hot skincare ingredients for 2018 are PHAs (polyhydroxy acids). PHAs are similar to AHAs but are a much better option for those with sensitive skin. Here's all you need to know about the acids and why they may well deserve a spot in your beauty stash.

What are PHAs?

PHAs are a form of acid exfoliation that lift off dead skin and promote cell renewal. They function the same as AHAs (alpha hydroxy acids), which include glycolic acid and lactic acid, however, PHAs have larger molecules, therefore causing much less irritation to the skin. Because of this larger molecule size, PHAs "cannot penetrate skin as deeply as traditional AHAs and BHAs. Instead, they work exclusively on the skin's surface without disturbing the delicate layers that lie beneath. This ensures optimum skin renewal with minimal irritation," said Daniel Isaacs, head of formulation and development at Medik8. This means that those with sensitive skin are more likely to be able to benefit from the use of acid exfoliants. As well as this, Isaacs noted that PHAs have powerful humectant properties, meaning they draw moisture from the air into the skin to hydrate, soften, and soothe it. Basically, if you like an acid exfoliant but find it a bit drying and irritating, PHAs could be the way forward for you.

What acids do PHAs include?

Common PHAs include gluconic acid (gluconolactone), which is naturally occurring in human cells. It's a particularly effective ingredient for those with pigmentation issues, as it triggers cellular regeneration. Isaacs explained that the acid works by "accelerat[ing] the skin-shedding process, ensuring that the darkened cells are efficiently dissolved away to reveal a brighter, clearer complexion." Another common PHA is galactose, which can help aid healing due to its collagen synthesis. Lactobionic acid is also a common PHA derived from the lactose in cow's milk and is a powerful antioxidant.

How do these work in skin care?

Isaacs said that both PHAs and AHAs work by "breaking down the 'glue' that binds dull, dead cells to the surface of the skin. This helps to speed up cellular turnover, minimizing fine lines and wrinkles, while revealing a brighter, smoother complexion." PHAs are a great addition to your skincare routine as they are natural antioxidants, which means they work by "neutralizing skin-damaging free radicals."

How to incorporate PHAs into your routine

If you love an acid in your skincare regimen but still like the feel of a physical exfoliant, I would recommend the Medik8 White Balance Cleanser ($57) as it uses a powder-to-foam formula to give your skin both psychical and acid exfoliation without being too harsh or irritating on the skin. I'm also a fan of the Exuviance Evening Restorative Complex ($48), which combines a blend of PHAs with vitamins for a powerful yet gentle night cream.