This fancy sounding ingredient is definitely a byproduct of once you ferment soybeans. Basically, “it is created when numerous glutamic acid molecules (an amino acid) are linked collectively,” notes board-certified dermatologist Hadley King, M.D. If that sounded too science-jargony, right here’s the breakdown: Amino acids are natural compounds which might be the constructing blocks of proteins in each vegetation and animals. “Amino acids play an instrumental function in some ways,” says board-certified dermatologist Keira Barr, M.D. “They’re concerned in lots of chemical reactions all through your physique to assist preserve your physique’s regular features, together with that of your pores and skin.” 

Because of this, they’re utilized in skincare—however there are various sorts of amino acids which might be extracted from a number of completely different sources (for skincare, the 2 commonest sources are soy and quinoa). When used topically, they’ll have quite a lot of features: Some act as an antioxidant and neutralize free radicals, some encourage your physique to make its personal antioxidants, and others assist transport water, successfully appearing as a hydrator. 

This ingredient falls into the final class as a humectant; humectants are lessons of hydrators that work by drawing in and holding onto water molecules. “Polyglutamic acid is a robust humectant that may maintain 4 instances extra water than hyaluronic acid,” says King. Hyaluronic acid, for reference, holds as much as 1,000 instances its weight in water.