Sodium Polygamma-Glutamate Crosspolymer: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: June 30, 2025
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We verify all information on this page using publicly available nomenclature standards from The Personal Care Products Council (PCPC), the European Commission's CosIng database and documentation provided directly by ingredient manufacturers. Our analysis is based on technical data from these sources to ensure accuracy and reliability.

What Is Sodium Polygamma-Glutamate Crosspolymer?

Sodium Polygamma-Glutamate Crosspolymer is a next-generation version of sodium polyglutamate, a biopolymer first discovered in the sticky strands of the Japanese fermented soybean dish called natto. The original polymer is produced when the bacterium Bacillus subtilis ferments plant-based substrates such as soybeans or sugarcane. To create the crosspolymer, manufacturers expose purified sodium polyglutamate to controlled gamma radiation. The energy from this process connects, or “crosslinks,” individual polymer chains, building a three-dimensional network that is more stable and water-binding than the starting material.

Commercial use began in Asia in the early 2000s, when researchers noticed that crosslinking boosted the polymer’s ability to cling to skin and hair without leaving a heavy residue. Its superior moisture retention and silky glide quickly gained attention from formulators looking for a plant-derived alternative to synthetic humectants. Today it appears in a range of cosmetic products, especially sheet masks, hydrating serums, anti-aging creams, leave-in hair treatments, and long-wear makeup where a stable emulsion is essential.

Sodium Polygamma-Glutamate Crosspolymer’s Cosmetic Benefits/Uses

This versatile ingredient supports formulas in several ways:

  • Emulsion stabilising: The crosslinked network thickens the water phase and helps oil and water stay evenly mixed, giving creams and lotions a smooth, uniform texture over time.
  • Hair conditioning: It forms an invisible film along the hair shaft that boosts slip, reduces static and improves softness without weighing strands down.
  • Humectant: The polymer’s sponge-like structure attracts and holds large amounts of water, enhancing skin hydration and helping products feel fresh and long-lasting on application.

Who Can Use Sodium Polygamma-Glutamate Crosspolymer

Sodium Polygamma-Glutamate Crosspolymer is generally suitable for all skin types. Its lightweight water-binding action benefits dry, normal and combination skin, while the non-greasy film it forms makes it comfortable for oily or acne-prone users. It is usually well tolerated by sensitive skin because it is nonionic and has a very low irritation profile. No specific skin type is considered incompatible, though anyone with a known allergy to fermented soy or related sources should proceed with extra caution.

The ingredient is produced through bacterial fermentation of plant substrates and involves no animal-derived materials, so it is appropriate for vegans and vegetarians.

Current safety data do not point to risks for pregnant or breastfeeding women when the crosspolymer is used in topical cosmetics. This is not medical advice, and anyone who is pregnant or nursing should review new products with a qualified healthcare professional to be safe.

Sodium Polygamma-Glutamate Crosspolymer is not known to cause photosensitivity, and it can be used in both daytime and nighttime products without requiring extra sun protection beyond normal daily sunscreen habits.

Potential Side Effects/Adverse Reactions

Individual reactions to topical Sodium Polygamma-Glutamate Crosspolymer can vary. The effects listed below are potential outcomes and are unlikely for most users when the ingredient is formulated correctly.

  • Mild redness or stinging in very sensitive skin
  • Contact dermatitis in people allergic to soy or fermentation by-products
  • Scalp or hair buildup leading to a weighed-down feel if overused in leave-in treatments
  • Rare interactions with highly cationic conditioning agents that may cause texture instability in a formula

If you experience any irritation or other adverse reaction stop using the product and consult a healthcare professional.

Comedogenic Rating

Rating: 0 / 5

Sodium Polygamma-Glutamate Crosspolymer is a large water-soluble molecule that does not clog pores or leave an oily residue, so it earns a non-comedogenic score of zero. Its primary role is to hold water and stabilise emulsions rather than create an occlusive film, making it friendly for people prone to blackheads and breakouts. Because it rinses away easily and does not accumulate in sebaceous follicles, the risk of pore blockage is negligible. One point worth noting is that products combining this polymer with heavy oils or waxes could still trigger acne, but any such reaction would come from the other ingredients rather than the crosspolymer itself.

Summary

Sodium Polygamma-Glutamate Crosspolymer acts as a humectant, emulsion stabiliser and lightweight hair conditioner. Its crosslinked structure soaks up water like a sponge then slowly releases that moisture to skin or hair, while its three-dimensional network thickens the water phase and keeps oil and water mixed for a smooth texture. The same scaffold creates a sheer film on strands that adds slip and softness without heaviness.

The ingredient is gaining traction in moisturising serums, sheet masks and long-wear makeup but is still considered a niche alternative to better-known humectants like hyaluronic acid. Safety data show a very low irritation profile, and it is non-comedogenic, vegan and generally safe for all skin types. As with any new cosmetic active it is wise to patch test a product containing Sodium Polygamma-Glutamate Crosspolymer before full use to rule out individual sensitivities.

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