Polyglutamic Acid: A Guide To The Hydrating Skin Care Ingredient

Let's say it together: You need to hydrate your skin! I'm going to assume you read that out loud enthusiastically, and move right along. But do you feel you are constantly looking for a moisturizer that actually gets the job done? Certainly there are a lot of us out there. Somehow, no matter what, we feel that by the end of the day our skin looks a bit dehydrated, stressed, and less than supple. Annoying, no?

If that sounds like you, you may consider polyglutamic acid (PGA). Before you are alarmed by the acid part, just know that this is an acid like hyaluronic, not the peel-your-face-off variety. And it's a relatively new ingredient—read: not brand-new to the market but fresh enough that it's still considered under-the-radar—that is considered to be one of the most effective humectants around. 

This fancy-sounding ingredient is actually a byproduct of when you ferment soybeans. Essentially, "it's created when lots of glutamic acid molecules (an amino acid) are linked together," notes board-certified dermatologist Hadley King, M.D. If that sounded too science-jargony, here's the breakdown: Amino acids are organic compounds that are the building blocks of proteins in both plants and animals. "Amino acids play an instrumental role in many ways," says board-certified dermatologist Keira Barr, M.D. "They're involved in many chemical reactions throughout your body to help maintain your body's normal functions, including that of your skin." 

For this reason, they are utilized in skin care—but there are many types of amino acids that are extracted from several different sources (for skin care, the two most common sources are soy and quinoa). When used topically, they can have a variety of functions: Some act as an antioxidant and neutralize free radicals, some encourage your body to make its own antioxidants, and others help transport water, effectively acting as a hydrator. 

Polyglutamic acid is a very tolerable ingredient—meaning anyone from sensitive-skin folk to oily skin types can use it. Those who will likely get the most benefits out of it are those with dry, irritated skin and those who naturally have a weakened skin barrier.