How to use polyglutamic acid?

Thepolyglutamic acid (PGA) is a biopolymer first isolated from the organism of the marine jellyfish. It allows it to store water in its delicate tissue, thus preventing accelerated dehydration due to its presence in the ocean's salty water. Today, PGA is extracted from a traditional Japanese food, the nattô, composed of fermented soybean seeds. It can also be biosynthesised from L-glutamic acid using the Gram-positive bacterium Bacillus subtilis.

From a chemical perspective, polyglutamic acid is apolymer derived from the amino acid glutamic. Its empirical formula is written as (C5H7NO3)n.In cosmetics, it is recognised for its hydrating action. It is capable of forming a protective film on the skin's surface that limits water evaporation. This is referred to as amicrogel; this structure swells and traps water, thus promoting its retention.Polyglutamic acid can retain up to 5,000 times its weight in water.

In order to hydrate the skin and thereby prevent the appearance of wrinkles and fine lines, various galenic forms contain polyglutamic acid and are now distributed in the cosmetic market. This active ingredient can thus be found in creams, lotions, and aqueous serums.

For effectiveness on the skin, polyglutamic acid must be concentrated at a minimum of 0.3% in a cosmetic formula. Generally, serums are the formulations that have a higher concentration of active ingredients, and therefore in PGA. However, it is advisable not to exceed 3% of PGA in a skin product. An overdose of polyglutamic acid can weaken the epidermal tissues and promote the appearance of redness. Therefore, its pure use is not recommended. Being an acid, a patch test on the inside of the elbow is recommended before any use. In case of intolerance, avoid using care products containing polyglutamic acid.