The differences between hyaluronic acid and polyglutamic acid.
Hyaluronic acid and polyglutamic acid are two similar biopolymers, known for their effectiveness in skincare thanks to their excellent hydrating properties. However, there are certain differences between them, not least their origin and chemical structure. Check out the differences in this article.
- Hyaluronic acid and polyglutamic acid: different origins
- Hyaluronic acid and polyglutamic acid: different chemical structures
- Cosmetic properties of hyaluronic acid and polyglutamic acid
- Combining hyaluronic acid and polyglutamic acid
Hyaluronic acid and polyglutamic acid: different origins.
Where does hyaluronic acid come from?
This biopolymer was first discovered in the vitreous humor of a bovine eye by Karl MEYER and John PALMER in 1934. It was subsequently extracted from the cartilage of oxen muzzle as well as from cockerel comb. It’s naturally present in the human body, found around the joints, in the muscles, in the eyes… However, the skin or, more precisely, the dermis, is the biggest reservoir for hyaluronic acid. Today, the hyaluronic acid used in skincare products is usually developed via biotechnological synthesis with bacteria.
Where does polyglutamic acid (PGA) come from?
This compound was first isolated from marine jellyfish, who use it to hold water in their fragile tissue to avoid dehydration caused by living in salty ocean water. Today, PGA is extracted from a traditional Japanese food, nattō, which is made from fermented soybeans. It can also be biosynthesized from glutamic acid using the Gram-positive bacterium Bacillus subtilis. Unlike hyaluronic acid, PGA is not naturally present in the human body.
Hyaluronic acid and polyglutamic acid: different chemical structures.
Hyaluronic acid is an unbranched linear chain made up of repeating disaccharide units of D-glucuronic acid and an aminoglycan, D-N-acetylglucosamine. Polyglutamic acid is a polymer derived from the amino acid L-glutamic. Its gross chemical formula is written (C5H7NO3)n.
To sum up, hyaluronic acid is formed from a chain of polysaccharides, while polyglutamic acid comes from the polymerisation of amino acids.
Cosmetic properties of hyaluronic acid and polyglutamic acid.
Both of these acids are known for their hydrating properties in skincare and hair care products. However, there are a few subtle differences in the ways in which they work and how they interact with the skin:
Hyaluronic acid is naturally present in the dermis, and plays a structural role. It works as a humectant, able to hold water within the cells. The way it works is directly linked to its molecular structure. It can fix a hundred sulphated proteoglycans to form supramolecular structures, which are then able to form bonds with water molecules and ions to maintain the skin’s hydration levels.
Hyaluronic acid is able to hold 1,000 times its own weight in water. Plus, it exists at two molecular weights. High-molecular weight hyaluronic acid stays at the skin’s surface and creates a protective film which stops water from evaporating. Low-molecular weight hyaluronic acid with a low molecular weight penetrates more deeply into the skin, to the bottom of the stratum corneum, to stimulate the body’s natural hyaluronic acid production.
Polyglutamic acid has a higher molecular weight than hyaluronic acid. It stays on the skin’s surface, rather than penetrating the skin. Its hydrating function is linked to its ability to form a protective film on the skin’s surface which prevents water evaporation. It’s known as a microgel; it swells and traps water, holding as much as possible. Polyglutamic acid is able to hold up to 5,000 times its weight in water.
Combining hyaluronic acid and polyglutamic acid.
Hyaluronic acid has been widely used in skincare products for many years, whereas polyglutamic acid is newer to the market. Combining these two molecules will give your skin a real hydration boost.
Hyaluronic acid will work on the internal cells of the dermis for long term hydration. It will help to oxygenate, tone and nourish your skin. Polyglutamic acid will form a protective film on the surface of your skin, preventing water evaporation.
Use our hydrating serum with hyaluronic acid, followed by our plumping serum with polyglutamic acid and red seaweed extract, in your morning and evening skincare routine.
DINI G. & al. Hyaluronic acid in cutaneous intrinsic aging. International Journal of Dermatology (1994).
GOLDMAN D. M. & al. Polyglutamic acid: a novel peptide for skin care. Cosmetics Toiletries Magazine (2007).