What Is Polygamma-Glutamic Acid?
Polygamma-glutamic acid, often shortened to γ-PGA, is a plant-derived biopolymer made of repeating glutamic acid units linked through gamma bonds. It occurs naturally in natto, the traditional Japanese food made by fermenting soybeans, and is produced on a larger scale by fermenting glutamic acid with Bacillus subtilis bacteria. After fermentation the thick gel is filtered, purified and dried into a fine powder that dissolves quickly in water. γ-PGA first gained attention as a food thickener and medical absorbent in the 1980s, but formulators soon noticed its impressive water-binding capacity and smooth feel on skin and hair. Today you will see it in sheet masks, hydrating serums, daily moisturizers, anti aging creams, leave-in conditioners, curl-defining gels and styling sprays.
Polygamma-Glutamic Acid’s Cosmetic Benefits/Uses
In skin and hair care formulas γ-PGA works in several helpful ways:
- Film forming – Creates an invisible flexible layer that locks in moisture, boosts softness and leaves skin or hair feeling silky not sticky
- Hair conditioning – Smooths the cuticle, reduces frizz and improves combability while adding light slip that does not weigh strands down
- Humectant – Attracts and holds many times its weight in water so it keeps skin plump, supports a healthy barrier and helps hair retain hydration even in dry air
Who Can Use Polygamma-Glutamic Acid
Because γ-PGA is a gentle humectant that sits on the surface rather than penetrating deeply it suits nearly every skin type including dry, oily, combination and sensitive. Its water-binding film helps dry skin hold on to moisture while its light texture avoids the heaviness that can bother oil-prone complexions. There are no known reasons for eczema-prone or rosacea-prone users to avoid it, though people dealing with open sores or active infections should consult a healthcare professional before applying any new product.
The ingredient is produced by fermentation of plant-derived glutamic acid with Bacillus subtilis so it is considered vegan and vegetarian friendly. No animal-based feedstocks or by-products are needed during manufacturing and no animal testing is required for γ-PGA itself in most regions.
Pregnant or breastfeeding women generally tolerate topical γ-PGA well because it remains on the skin surface and is not known to absorb into the bloodstream. Still, this is not medical advice and anyone who is expecting or nursing should review all skincare choices with a qualified doctor to be safe.
γ-PGA does not cause photosensitivity, so it will not make skin more prone to sunburn. Standard daily sun protection is still recommended for overall skin health. The ingredient also plays nicely with most actives such as vitamin C, niacinamide and retinoids so you can layer it without worrying about inactivation.
Potential Side Effects/Adverse Reactions
Side effects from topical polygamma-glutamic acid vary from person to person. The points below list potential reactions, yet they are uncommon when the ingredient is correctly formulated and used as directed.
- Mild redness or stinging – Usually transient and linked to very sensitive skin or over-exfoliated skin barriers
- Temporary tight feeling – Can occur if the product has a high polymer concentration that forms a strong film on the surface
- Allergic contact dermatitis – Rare but possible in individuals with specific sensitivities to fermentation by-products or preservatives in the finished formula
- Product buildup on hair – Occasional with heavy leave-in styling products containing high levels of γ-PGA, leading to dullness until shampooed out
If you notice persistent irritation, itching or any other discomfort stop using the product and seek guidance from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 0 – Polygamma-glutamic acid is water soluble, forms a breathable film and has a large molecular size that sits on the surface instead of sinking into pores. It does not contain oily residues that can trap dead cells or sebum, so it is unlikely to clog follicles. Because of this, the ingredient is generally suitable for acne-prone or breakout-prone skin. Formulas that combine γ-PGA with heavy oils or waxes could still pose a clogging risk, but the polymer itself is non-comedogenic.
Summary
Polygamma-glutamic acid works as a film former, humectant and light hair conditioner. It grabs and holds water like a sponge, then lays down a soft flexible layer that keeps that moisture from escaping. On hair, the same film smooths the cuticle for shine and easier detangling without adding weight.
Although not as famous as hyaluronic acid or glycerin, γ-PGA is gaining fans thanks to its strong water binding and silky afterfeel. You will spot it more often in hydrating serums, sheet masks and leave-in hair products as brands look for fresh yet gentle moisturizers.
Topically applied γ-PGA has an excellent safety record with very low irritation or allergy reports. As with any new cosmetic ingredient, a small patch test is wise before full use to confirm personal compatibility.