Polyglutamic acid is a recent compound in the skincare field. However, more scientific studies explore this ingredient and highlight its hydrating and regenerating properties. Here are the main benefits of polyglutamic acid for topical use.
Library
All Topics
What are the benefits of polyglutamic acid for the skin?
Summary
- Benefit No. 1: Polyglutamic acid hydrates the skin
- Benefit No. 2: Polyglutamic acid could slow wrinkle formation
- 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 the skin.
L-polyglutamic acid is a water-soluble peptide formed by polymerising glutamic acid from soya bean fermentation. This compound is known for its action against skin dehydration. It acts on several levels to maintain skin water balance. First, polyglutamic acid forms a microscopic film on the epidermal surface called a microgel. This molecular structure swells on contact with water and traps water molecules. Through this mechanism, the polyglutamic acid can retain up to 5,000 times its weight in water. By comparison, depending on its molecular weight, the hyaluronic acid can retain up to 1,000 times its weight in water.
Polyglutamic acid boosts the production of pyrrolidone carboxylic acid, lactic acid and urocanic acid, molecules that compose the natural moisturising factors (NMF). This term refers to a group of hygroscopic substances in the stratum corneum that retain water. It inhibits hyaluronidase activity, the enzyme responsible for degrading hyaluronic acid in the dermal tissue. This molecule is well-known in skincare. It is linked to skin hydration and gives a plumped appearance. Levels decline over time, leading to skin dryness and contributing to the development of wrinkles. By inhibiting hyaluronidase, polyglutamic acid helps prevent skin dehydration and slows the emergence of signs of ageing.
The hydrating properties of polyglutamic acid were examined in several studies. One study in 2019 included five participants. They spent fifteen minutes in a room at 22°C and 60% humidity. Two formulations were applied to each arm. One contained 0.2% polyglutamic acid. The other contained 5% glycerol, a common humectant in topical formulations. Hydration was measured by corneometry before and two hours after application. An increase of 13.5% in skin hydration was measured after application of the polyglutamic acid formulation, compared with 7.5% for the glycerol formula.
4 minutes to understand your skin.
Our dermatological diagnostic guides you toward the ideal skincare for your specific needs.
Simple, quick, personalized.
Benefit No. 2: Polyglutamic acid could slow wrinkle formation.
Skin ageing is due to intrinsic factors such as reduced cell renewal, changes in dermal composition and constituent molecules (hyaluronic acid, collagen) and the loss of fat and muscle tissue that no longer provides support. Extrinsic factors, related to lifestyle, can also accelerate the process (poor diet, smoking, excessive alcohol consumption, exposure to sunlight, stress, lack of sleep). As a result, the skin becomes drier, wrinkles deepen and pigmented spots may appear.
If polyglutamic acid cannot address all these processes, it can combat skin dehydration, as described in the previous section, and prevent dehydration lines, those fine furrows that form around the eye contour and lips. An in vitro study showed that polyglutamic acid could upregulate the expression of the col1a1a and col1a1b, linked to collagen production, and the eln1 and eln2, associated with elastin synthesis. If clinical trials confirmed these results, it would mean that polyglutamic acid could help to maintain skin suppleness and elasticity.
Benefit No. 3: Polyglutamic acid to accelerate skin healing.
Traditionally, polyglutamic acid was used in medicine to accelerate healing of wounds and minor burns. Studies in vivo on rats showed that topical application of high-molecular-weight polyglutamic acid reduced the injured area by the eighth day after incision, achieving over 70% repair. Researchers observed epidermal regeneration in histological analyses. This suggests polyglutamic acid promotes rapid re-epithelialisation.
Beyond wound closure, polyglutamic acid also modulates the remodelling phase. At day 16, treated tissues showed a higher collagen density with improved fibrillar organisation and a more developed vascular network compared with controls. This activity may be partly linked to a local increase in factors involved in tissue regeneration, notably TGF-β and β-catenin, two key mediators in cell proliferation, collagen synthesis and angiogenesis. These findings suggest polyglutamic acid could 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).
Diagnostic
Understand your skin
and its complex needs.
