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Dr. Alpana Mohta Ranka, MD, DNB, IFAAD, is a triple-board-certified dermatologist with over 100 research publications in peer-reviewed scientific journals.


Polyglutamic Acid Serum: Benefits, Uses, and Expert Recommendations

Polyglutamic acid serum is making waves in the skincare industry as a potent hydrator. This guide covers everything you need to know about polyglutamic acid, from its benefits and uses to expert recommendations and comparisons with hyaluronic acid.

An image showing polyglutamic acid containing skincare

What is Polyglutamic Acid?

Polyglutamic acid is a biopolymer derived from the fermentation of Bacillus subtilis, commonly found in natto, a traditional Japanese food made from fermented soybeans. It is a humectant like glycerin and draws moisture from the air, sealing it into the top layers of our skin. Due to its high molecular weight, it forms a film on the skin's surface, trapping moisture and enhancing hydration​.

Polyglutamic Acid Benefits

1. Superior Hydration

Polyglutamic acid serum can hold up to 5,000 times its weight in water, making it one of the most effective humectants available. To put this into perspective, hyaluronic acid can hold 1,000 times its weight in water, sodium PCA about 250 times, urea about 1.5 times, glycerin about 0.5 times, and propylene glycol about 0.5 times its weight in water.

According to a research paper from Frontiers in Microbiology, polyglutamic acid forms a soft, smooth, thin film that releases water gradually into the skin, reducing transepidermal water loss from the surface of the skin and increasing the production of natural moisturizing factors.

2. Enhances Skin Elasticity

Research has also found that by forming a protective film on the skin, polyglutamic acid serum helps maintain elasticity and smoothness. This can reduce the appearance of fine lines and wrinkles, giving the skin a more youthful look​.

3. Boosts Other Skincare Ingredients

Polyglutamic acid can inhibit the enzyme hyaluronidase, which breaks down hyaluronic acid in the skin. This means using a serum containing polyglutamic acid can actually enhance the effectiveness of hyaluronic acid, making your skincare routine even more efficient​.

4. Suitable for All Skin Types

polyglutamic acid serum is super mild and works well for all skin types, including sensitive skin. Its gentle nature makes it a versatile addition to any skincare regimen.

5. Additional Benefits

Polyglutamic acid serum is not only used in skincare but also has potential applications in wound healing and the food industry due to its biocompatibility and effectiveness in promoting the regeneration of skin cells.

How to Use Polyglutamic Acid Serum

  1. Cleanse: Start with a gentle cleanser to remove impurities.

  2. Serum: Apply a serum containing polyglutamic acid. This step ensures maximum absorption and effectiveness.

  3. Moisturize: Follow with your favorite moisturizer to lock in hydration.

  4. Protect: In the morning, always finish with a broad-spectrum sunscreen.

  5. Layering: Use polyglutamic acid serum before heavier creams or oils to ensure it penetrates the skin effectively.

  6. Frequency: Incorporate polyglutamic acid serum into your routine once or twice daily, depending on your skin’s needs.

Polyglutamic Acid Serum vs. Hyaluronic Acid Serum

While both are powerful humectants frequently used in cosmetics and cosmeceuticals, polyglutamic acid can hold significantly more water than hyaluronic acid. However, they work best when used together, as polyglutamic acid can enhance the longevity and effectiveness of hyaluronic acid in the skin​.

Expert Recommendations

For Dry Skin

Combine polyglutamic acid serum with ceramides and fatty acids to strengthen the skin barrier and prevent moisture loss​ and skin dryness.

For Oily Skin

Polyglutamic acid serum can be paired with lightweight, non-comedogenic moisturizers to provide hydration without clogging pores​.

For Sensitive Skin

Although polyglutamic acid is very gentle and free from side effects, if you have sensitive skin opt for fragrance-free formulations.

Dermatologist-Recommended Polyglutamic Acid Serums

As a dermatologist, I recommend the following polyglutamic acid products for their efficacy and formulation:

1. The Inkey List Polyglutamic Acid Serum

Why it works: This serum not only provides intense hydration but also forms a breathable film on the skin to lock in moisture. It works well under make-up and other skincare products, making it an excellent choice for daily use. Its affordability and effectiveness make it a standout product.

2. Charlotte Tilbury Magic Serum Crystal Elixir

Why it works: Formulated with polyglutamic acid, this serum also contains a blend of rejuvenating active ingredients like vitamin C and niacinamide. It hydrates, brightens, and improves skin texture, making it a versatile addition to any skincare routine.

3. SeoulCeuticals Organic Polyglutamic Acid Serum

Why it works: This Korean serum is enriched with polyglutamic acid, hyaluronic acid, and ginsen, offering deep hydration and anti-aging benefits. It's a lightweight formula that absorbs quickly, making it suitable even for the eye area.

Are Glutamic Acid and Polyglutamic Acid Same?

Glutamic acid and polyglutamic acid are not the same. Glutamic acid is a single amino acid, essential for protein synthesis and neurotransmission in the body. In contrast, polyglutamic acid is a polymer made up of multiple glutamic acid molecules linked together. While glutamic acid functions primarily in cellular metabolism and signaling, polyglutamic acid is known for its ability to retain moisture in skincare products.


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