What is Polyglutamic Acid?

What is Polyglutamic Acid?

Polyglutamic acid or really any acid sounds like something you would want to avoid putting on your skin, especially your face. However, there are many acids incorporated into skincare products because of their exfoliating and brightening properties. Polyglutamic acid naturally appears in fermented soybeans but it was “discovered” by accident in 1937.

Glutamic acid is an amino acid, it is created when lots of glutamic acid molecules are linked together. This acid functions differently from most acids used for skincare. After its properties were analyzed, it was discovered that polyglutamic acid was an incredibly powerful humectant moisturizer. But only recently has it become a skincare obsession.

So what exactly is a humectant?

Basically, there are three main types of moisturizers: emollient, humectant, and occlusive. Emollient moisturizers penetrate into the skin and reduce water loss and occlusive moisturizers coat the skin in a layer of film that prevents water from evaporating.

Humectant moisturizers are almost a combination of these two, they penetrate the skin and create a barrier, but they also attract water from the air and maintain moisture. However, in dry conditions, humectants can draw water from the inner layers of the skin which may actually cause drying. Adding an occlusive moisturizer as a second layer might be the best way to really lock in that moisture.

Polyglutamic acid or PGA can hold 4000 times its weight in water, this is quadruple the efficacy of water retention compared to hyaluronic acid or HA. HA is produced naturally in our skin, it binds water to collagen trapping it in our skin resulting in a plump, hydrated skin.

what is polyglutamic acid mirra skincare infographic skincare products

As we age we produce less hyaluronic acid, which is broken down by an enzyme called hyaluronidase. PGA helps to inhibit the action of hyaluronidase, leaving more HA in the skin. The combination of these two ingredients is truly a hydrating force! Some of the other benefits of PGA include: 

  1. Plumps skin reducing the appearance of existing fine lines and wrinkles 
  2. Enhances elasticity to help prevent new fine lines and wrinkles from forming
  3. Slows the aging process by inhibiting the breakdown of natural hyaluronic acid found deep within the skin
  4. Increases the production of natural moisturizing acids, such as lactic acid
  5. Helps your skin absorb other skincare products and ‘seal’ them in.

If this ingredient is as good as it seems then why haven’t we seen it on the market? Well, the short answer is price. PGA is more expensive to manufacture and HA functions to produce the same results. Cost aside, studies show that PGA does deliver results. It is best for dry skin types as they are simply in need of more moisture. In addition, it mixes well with other products especially water-based ones and it works for all skin types. 

Moisturising is arguably the best way to keep your skin looking young. When skin is fully hydrated, fine lines and wrinkles do not form as easily and your skin is able to more efficiently distribute the nutrients your skin needs. Dehydrated skin can often be itchy, sensitive, and dull. Drinking lots of water is one way to get moisture into your skin, but PGA will help you retain that moisture. 

How to use it

A simple but thorough skincare routine consists of cleansing, toning, applying antioxidant serums, applying a hyaluronic acid product, then applying polyglutamic acid to seal everything in before finishing with sunscreen. PGA is best used in combination with HA. Dr. Shaaira Nasir, a consultant dermatologist at Homerton University Hospital explained: “These two ingredients have a synergistic effect, as polyglutamic acid stops hyaluronic acid from breaking down. Of those, the two ingredients, apply polyglutamic acid second, as its gel-like consistency locks in hyaluronic acid, which has a more watery consistency.”

However, if you have oily skin using PGA alone should be enough extra hydration for your skin. PGA can be applied twice a day, in the morning and again at night. If you’re using PGA in serum form, make the most of it by allowing the product to sink in fully before layering other products.

Side Effects

Currently, there are no known negative side effects of PGA. However, as with any ingredient, your body can be allergic and experience an allergic reaction. You could also become desensitized with overuse and it could require more of that ingredient to produce the same effect. If you do notice a negative reaction, stop using the product and consult a dermatologist if necessary. 


After browsing through a few dozen PGA products here are some of the ones I might be trying out:

  • The Inkey List, Polyglutamic Acid:  This product is only $22.99 on Amazon, boasts 4.5/5 stars and a 3% PGA content. Some users say they can see a difference in as little as 2 applications
  • Then I Met You, Giving Essence: This product, only available from Then I Met You has a 4-star overall rating with users saying it's a bit more expensive but praising its lifespan and hydrating ability. Giving Essence contains not only PGA but galactomyces, niacinamide, black chokeberry, ellagic acid and red algae. All of these ingredients work together to provide a powerful hydration boost. 

Final Thoughts

I don’t know about you but after this article, PGA is an ingredient I want to try, and I want to try it soon. I think as it becomes more popular the cost to manufacture it will go down; hopefully, this will make products containing this ingredient more affordable. But overall, I think that this skincare ingredient sounds very interesting and I'm curious to see how it would react to my skin.

Written by Kiana St Onge


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