Polyglutamic Acid Holds 4-5x More Moisture Than Hyaluronic

Hyaluronic acid has dominated hydrating skincare since Eva Longoria highlighted the ingredient on national television in 2019. Dermatologists frequently cite its capacity to hold 1,000 times its weight in water, making it a staple in serums, moisturizers, and skin tints. However, polyglutamic acid (PGA) is emerging as a competitor for shelf space.

What Is Polyglutamic Acid?

Despite recent popularity, PGA is not new. Board-certified dermatologist Divya Shokeen, MD, describes it as a high-molecular-weight water-soluble peptide or polymer produced via bacterial fermentation. Unlike exfoliating acids such as glycolic or salicylic, PGA functions as a humectant, attracting and retaining water to plump the skin. Dr. Shokeen notes it can hold four to five times more moisture than hyaluronic acid.

Rishi Chopra, MD, another board-certified dermatologist, explains that PGA helps attract and hold water at the skin’s surface, replenishing dry, dull complexions and smoothing crepiness and fine lines. It belongs to the same category as glycerin and urea, found in face creams, serums, and certain cleansers.

Alexandra Bowles, DO, adds that PGA consists of chains of glutamic acid, an amino acid naturally occurring in the body. The ingredient was first identified in natto, a fermented soybean food, and is typically produced through bacterial fermentation.

How Does It Benefit Skin?

Hydration remains the primary benefit. According to Dr. Bowles, PGA attracts and binds water to the skin’s surface, resulting in softer, smoother, and less tight skin. Dehydration-related fine lines may appear less noticeable, though the ingredient does not rebuild collagen or reverse aging.

Dr. Shokeen states that PGA forms a flexible, protective film on the skin’s surface. This creates a dewy, smooth finish while delivering the hydration benefits described by Dr. Bowles.

Is It Better Than Hyaluronic Acid?

Experts suggest PGA is not a replacement for hyaluronic acid but a complementary tool. While both are humectants, they function differently. Dr. Bowles explains that PGA is a very large molecule that tends to stay on the skin’s surface rather than penetrating deeply.

In contrast, hyaluronic acid comes in various molecular weights, allowing it to deliver hydration to both surface and deeper layers depending on the formulation. Dr. Shokeen recommends using both together: HA for deep multi-depth hydration and PGA for surface-level moisture retention, smoothing, and a dewier finish.

Dr. Chopra notes that hyaluronic acid has a longer clinical track record, but most people do not need to choose between the two. Since many routines already include HA, PGA offers an additional layer of hydration without significant irritation risks.

Usage and Suitability

Integrating PGA into a routine is straightforward. It generally does not cause irritation, so users do not need to start slowly or alternate days, though patch testing is advised for reactive skin. It pairs well with potentially irritating ingredients like retinol and vitamin C.

Application depends on the product format. Serums should be applied after cleansing and before moisturizer, following specific formula directions. Moisturizers containing PGA are used after serums and toners.

Dermatologists agree PGA suits most skin types, particularly dry, dehydrated, mature, and sensitive skin due to its gentle nature. It is usually considered non-comedogenic, making it suitable for acne-prone patients. However, Dr. Bowles cautions that those with very oily skin or living in humid climates might find the protective film heavy or sticky. Individuals with allergies to PGA should avoid it, and those with sensitive skin should check other formula ingredients for potential adverse reactions.

Expert Recommendations

The article features insights from three specialists:

• Rishi Chopra, MD: Harvard fellowship-trained, board-certified cosmetic dermatologist; Skin Longevity Director at Hudson Dermatology & Laser Surgery in NYC.
• Divya Shokeen, MD: Board-certified dermatologist.
• Alexandra Bowles, DO: Board-certified dermatologist.

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