Why polyglutamic acid is the serum your skincare routine is missing

Medically reviewed words Annie Hayes, Dr Roger Henderson
Photo credit: Jonathan Knowles

From Netdoctor

Polyglutamic acid (often abbreviated to PGA) holds up to 10 times more moisture than cult skincare ingredient hyaluronic acid (or HA), making it one of the most powerful hydrating ingredients around for tired, dry and dehydrated skin.

The hydrating serum is a favourite among beauty bloggers, who’ve been touting top products – such as The Inkey List’s polyglutamic acid – and praising the skin benefits of polyglutamic acid more generally.

From slowing down the ageing process to boosting skin elasticity, we asked dermatologists to discuss polyglutamic acid skin benefits, advise how to incorporate this product into your skincare routine, and explain whether you should ditch hyaluronic acid for good:

What is polyglutamic acid?

Polyglutamic acid is a water soluble peptide (a type of protein) derived from the mucilage of fermented soya beans, explains Dr Shaaira Nasir, consultant dermatologist at skin.

It’s a humectant, which means it attracts moisture and draws into your skin. Plus, its ‘large molecules prevent water loss by forming a film over the top layer’, she explains.

Polyglutamic acid has the ability to hold up to 10 times more moisture than hyaluronic acid (or HA), which is frequently hailed as a top-tier hydrating skincare ingredient.

It’s available in a variety of different products, including serums, face creams, eye creams, toners and masks.


Polyglutamic acid skin benefits

Looking across air pollution, central heating, seasonal changes and lifestyle habits (such as drinking alcohol, consuming caffeine), there are a vast variety of factors that can contribute to dehydrated skin, and often without us even realising it.

Dehydrated skin is often itchy, sensitive, dull and tired, and appears to have accelerated signs of ageing, such as fine lines and wrinkles. As well as, say, drinking enough water, you should also look to minimise water loss through your skin – and this is where polyglutamic acid comes in.

Often described as a ‘super-hydrator’ and impressively, it can hold up to 5,000 times its own weight in water.

Possible skincare benefits of polyglutamic acid include:

  • Plump skin to smooth out existing fine lines and wrinkles for a younger-looking complexion
  • Enhance elasticity to help prevent new fine lines and wrinkles from forming
  • Slow the ageing process by inhibiting the breakdown of natural hyaluronic acid found deep within the skin
  • Increase production of natural moisturising acids, such as lactic acid
  • Help your skin absorb other skincare products and ‘seal’ them in.

What’s the difference between polyglutamic acid and hyaluronic acid?

Hyaluronic acid has long been hailed as a hero-hydrating ingredient: able to hold up to 1000 times its own weight in water, HA helps to keep skin hydrated by boosting the water content in skin cells. It occurs naturally in the skin but over time, as we age, the level of hyaluronic acid secreted begins to diminish.

Polyglutamic acid, on the other hand, is up to 10 times more hydrating than hyaluronic acid. Like HA, PHA draws water into the cells. However, PGA even goes one step further as it also seals the moisture in by forming a protective film on your skin that prevents moisture from evaporating.

In other words, hyaluronic acid will hydrate deeper into the skin, while polyglutamic acid nourishes the top layer of the skin, but also protects and plumps your skin.

How to use polyglutamic acid

Polyglutamic acid is best used around the moisturising stage of your routine, says Dr Simon Zokaie, dermatologist and skin expert at private clinic bookings app Zoom, to help hydrate the skin, enhance elasticity – to reduce the appearance and signs of premature ageing – as well as refresh and nourish, so your skin feels smoother.

If you have dry or dehydrated skin, polyglutamic acid should be used in combination with hyaluronic acid to maximise skin hydration, says Dr Nasir. ‘These two ingredients have a synergistic effect, as polyglutamic acid stops hyaluronic acid from breaking down. Of those the two ingredients, apply polyglutamic acid second, as its gel-like consistency ‘locks in hyaluronic acid, which has a more watery consistency,’ she says.

Those with have oily skin would be best sticking to polyglutamic acid only. So, in terms of your skincare routine: cleanse, tone, apply any antioxidant serums (followed by a hyaluronic acid product, if applicable), ‘then apply polyglutamic acid to seal everything in before moisturiser and sunscreen,’ Dr Nasir clarifies.

Given its hydrating properties, polyglutamic acid can be applied twice a day. If you’re using polyglutamic acid in serum form, to make the most of its powers allow the product to sink in fully before layering products over the top.

Polyglutamic acid side effects

Despite the connotations involved with applying an ‘acid’ to your skin, there are no side effects associated with using polyglutamic acid. Given that it’s deeply hydrating, this product is ideal for all skin types. However, ‘as with any formulations, one can be or may become sensitised to any of the base products or ingredients,’ says Dr Zokaie.

If you have any questions about a product that contains polyglutamic acid, or are concerned that you might be experiencing an adverse side effect, stop using it immediately and consult a dermatologist.


Last updated: 24-06-2020

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