Glutamic acid is an amino acid. Polyglutamic acid is created when lots of glutamic acid molecules are linked together," says Wong. "It's produced by bacterial fermentation and is found in Nattō." [Ed note: Nattō is a traditional Japanese food made from fermented soybean.]

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.