Polyglutamic acid is a recent compound in the cosmetics industry. More scientific studies have been conducted on this ingredient, highlighting its hydrating and regenerating properties. Here are the main benefits of topical polyglutamic acid.
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What are the benefits of polyglutamic acid for the skin?
Summary
- Benefit No. 1: Polyglutamic acid hydrates skin
- Benefit No.2: Polyglutamic acid may slow the formation of wrinkles
- Benefit No. 3: Polyglutamic acid to accelerate skin healing
- Benefit No. 4: Polyglutamic acid has a soothing potential
- Sources
Published December 21, 2021,
updated on June 15, 2025,
by
Maylis, Chemical Engineer
—
7 min read
Benefit No. 1: Polyglutamic acid hydrates skin.
The polyglutamic acid is a water-soluble peptide formed by polymerizing glutamic acid derived from fermented soybeans. This compound is known for reducing skin dehydration. It works on several levels to maintain the skin’s water balance. First, polyglutamic acid forms a microscopic film on the epidermal layer called a microgel. This molecular structure swells on contact with water and traps water molecules. Through this mechanism, the polyglutamic acid can hold up to 5,000 times its weight in water. By comparison, depending on its molecular weight, the hyaluronic acid can hold up to 1,000 times its weight in water.
Polyglutamic acid increases production of pyrrolidone carboxylic acid, lactic acid, and urocanic acid, molecules composing the natural moisturizing factor (NMF). This term refers to hygroscopic substances in the stratum corneum that retain water. Polyglutamic acid limits hyaluronidase activity, the enzyme responsible for degrading the hyaluronic acid present in dermal tissue. This molecule is known for its role in skin hydration and gives skin a plumped appearance. Its level decreases over time, leading to skin dryness and contributing to wrinkle formation. By inhibiting hyaluronidase activity, polyglutamic acid prevents skin dehydration and slows signs of aging.
The hydrating properties of polyglutamic acid were examined in various studies, including a 2019 trial with five volunteers. They spent 15 minutes in a room at controlled temperature (22°C) and humidity (60%). Two formulations were applied to each volunteer’s arms: one contained 0.2% polyglutamic acid and the other 5% glycerol, a common moisturizer. Hydration was measured by corneometry before and two hours after application. A 13.5% increase in skin hydration was recorded after applying the polyglutamic acid formula, compared with 7.5% for the glycerol-based formula.
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Benefit No.2: Polyglutamic acid may slow the formation of wrinkles.
Skin aging results from intrinsic factors such as reduced cell turnover, changes in dermal composition and its molecules (hyaluronic acid, collagen), and loss of fat and muscle tissue that no longer provides support. Extrinsic lifestyle factors can also accelerate the process (poor diet, smoking, excessive alcohol consumption, exposure to sun, stress, lack of sleep...). As a result, the skin becomes drier, wrinkles deepen, and pigmented spots may appear.
Although polyglutamic acid cannot address all these processes, it can counter skin dehydration, as explained above, and prevent dehydration lines, those small creases at the eye contour and lips. Moreover, an in vitro study showed that polyglutamic acid could upregulate expression of the genes col1a1a and col1a1b, linked to collagen production, and the genes eln1 and eln2, associated with elastin synthesis. If these results were confirmed in clinical settings, it would indicate that polyglutamic acid could help maintain skin suppleness and elasticity.
Benefit No. 3: Polyglutamic acid to accelerate skin healing.
Traditionally, polyglutamic acid has been used in medicine to accelerate wound-healing processes in injuries and minor burns. Studies in vivo on rats showed that topical application of high-molecular-weight polyglutamic acid reduced the damaged area by the eighth day after incision, achieving over 70% repair. Histological analyses also confirmed epidermal regeneration, suggesting rapid reepithelialization promoted by polyglutamic acid.
Beyond wound closure, polyglutamic acid modulates the remodeling phase. At 16 days, treated tissues showed increased collagen density with improved fibrillar organization and a more developed vascular network compared with controls. This activity is linked in part to a local increase in factors involved in tissue regeneration, including TGF-β and β-catenin, two key mediators in cell proliferation, collagen synthesis, and angiogenesis. These results suggest polyglutamic acid may support skin repair and accelerate healing of minor wounds.
Benefit No. 4: Polyglutamic acid has a soothing potential.
Cutaneous inflammation manifests through a series of visible signs, such as redness and swelling, as well as invisible symptoms like itching. The inflammatory response involves the release of numerous mediators, including cytokines and prostaglandins, which locally alter vascular permeability and promote the recruitment of immune cells. While inflammation is a normal and beneficial process when the body is under threat, it can become harmful and damage the skin barrier if it becomes chronic.
Preclinical research suggests that polyglutamic acid may indirectly help regulate inflammatory responses in the skin. By limiting the expression of certain mediators involved in inflammatory angiogenesis, such as VEGF-A and its receptor VEGFR2, this active compound may slow down excessive vascular activation seen in chronic inflammation. In doing so, polyglutamic acid may help reduce redness, swelling, and the sensation of heat associated with skin irritation. However, in the absence of clinical studies, these hypotheses still need to be confirmed before polyglutamic acid can be considered a soothing ingredient or suitable for reactive or sensitive skin.
Sources
SONA H.-J. & al. In vitro evaluation of new functional properties of poly-γ-glutamic acid produced by Bacillus subtilis. Saudi Journal of Biological Sciences (2014).
RADECKA I. & al. Poly-γ-glutamic acid: production, properties and applications. Microbiology Society (2015).
SUNG M.-H. & al. Promotion effects of ultra-high molecular weight poly-γ-glutamic acid on wound healing. Journal of Microbiology and Biotechnology (2015).
HIURA N. & al. Characterization of poly(L-glutamic acid)-grafted hyaluronan as a novel candidate medicine and biomedical device for intra-articular injection. Journal of Biomedical Materials Research (2017).
YANG S.-A. & al. Gamma polyglutamic acid (gamma-pga, h form), gamma-polyglutamate hydrogels for use as super moisturizers in cosmetic and personal care products (2019).
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