Is sodium polyglutamate 500 times more moisturizing than hyaluronic acid?

In recent years, PGA has frequently appeared in the ingredient lists of high-end skincare products. From international brands to emerging domestic brands, it seems everyone is quietly investing in this "low-key powerhouse." Along with its popularity, an astonishing figure has circulated in the beauty industry: PGA's moisturizing ability is 500 times that of hyaluronic acid. Is there any scientific basis for this claim?

Is PGA's moisturizing ability really 500 times that of hyaluronic acid?

This figure has a source, but it needs to be in big quotation marks.

The "500 times" claim is not unfounded. Multiple industry reports and raw material supplier technical data show that, under specific experimental conditions, PGA does indeed exhibit an amazing water-absorbing potential—it can absorb 4000-5000 times its own weight in water, while hyaluronic acid's generally accepted water absorption capacity is about 1000 times its own weight. Based on this calculation, a 4-5 times difference is exaggerated to "500 times" by some marketing outlets, which is a misrepresentation.

What are the truly rigorous experimental data?

According to research by industry expert Zhu Xiqiang and his team, as reported by Xueqiu, sodium polyglutamate (PGA) has a long-term moisturizing effect approximately 7-8 times that of hyaluronic acid in skin moisturizing comparison tests, and is less affected by environmental humidity. Another study published in a professional journal shows that SPG with a molecular weight of 1200 kDa has the best moisturizing effect at a concentration of 0.1%, and its sustained moisturizing power is significantly better than that of sodium hyaluronate with the same molecular weight.

Why such a large difference in data?

This depends on three key variables:

Different testing environments: In a dry environment (relative humidity 43%), SPG has a clear advantage in moisturizing rate; while in a high-humidity environment (RH 81%), the difference narrows.

Molecular weight differences: SPG has a very wide molecular weight range (50,000-2,000,000 Daltons), and the moisturizing efficacy varies drastically depending on the molecular weight. High molecular weight (1 million+) molecules form a water-locking film, while low molecular weight (<100,000) molecules focus on penetration.

Evaluation dimensions differ: simple water absorption ratio vs. actual skin moisture content change rate (MMV) vs. transepidermal water loss (TEWL) inhibition rate; the results are drastically different.

Industry truth: 500 times is the theoretical limit; 7-8 times is a clinically proven advantage. Any discussion of multiples without considering molecular weight, concentration, and testing conditions is misleading.

Why is sodium polyglutamate considered a "smart" moisturizing ingredient?

If hyaluronic acid is a "water-absorbing PGAnge," then sodium polyglutamate is more like a "skin humidity manager"—it not only replenishes moisture but also actively regulates the skin's hydration ecosystem. This is why it is called "the only ingredient that can induce the self-increase of natural moisturizing factor (NMF)."

1. Dual Moisturizing Mechanism: External Hydration Locking + Internal Regeneration Promotion The high molecular weight structure of sodium polyglutamate (especially at 1-2 million molecules) forms a breathable protective film on the skin surface, reducing transpiration water loss (TEWL). More importantly, it inhibits the activity of hyaluronic acid-degrading enzymes, protecting the skin's own hyaluronic acid from excessive degradation and prolonging the moisturizing effect from the source. Simultaneously, it stimulates the stratum corneum to produce more NMF components (such as pyrrolidone carboxylic acid and lactic acid), allowing the skin to "moisturize itself."

2. Active Ingredient "Booster" It's no coincidence that sodium polyglutamate is often combined with hyaluronic acid in the formulas of international brands like Clinique and Dior. Studies have shown that it can act as a "carrier" ingredient, increasing the transdermal absorption rate of active ingredients such as vitamin C and collagen by 30%-50% by opening the skin's aquaporin channel protein (AQP3). A whitening serum patent shows that adding 0.8-1.5% sodium polyglutamate can double the penetration rate of niacinamide and arbutin.

3. Microecological Barrier Repair
Unlike hyaluronic acid, which may cause a sticky feeling, sodium polyglutamate (SPG) maintains the skin's pH within a healthy, slightly acidic range, inhibits the growth of harmful bacteria, and promotes keratinocyte proliferation, accelerating barrier repair. This is especially valuable for sensitive skin and skin after cosmetic procedures.

How to Choose Sodium Polyglutamate with Different Molecules?

Why is 1,100,000 so popular?
Because it strikes the perfect balance between "penetrating to the deepest layers of the epidermis" and "forming a water-locking network on the surface," achieving a synergistic effect of 1+1>2. However, recent research indicates that 1200kDa (1,200,000) has the best moisturizing effect at a concentration of 0.1%. This data comes from experiments in authoritative journals and is more valuable for reference.

Purchase Guide to Avoiding Pitfalls

Look at Compound Formulas: The single-ingredient theory is outdated. High-quality formulas combine different molecular weight sodium polyglutamate (e.g., 100,000 + 1,100,000), or work synergistically with hyaluronic acid and panthenol to achieve comprehensive moisturizing.

Concentration Considerations: 0.1%-0.5% is the effective range; higher concentrations may cause pilling. Be wary of products claiming to be "pure sodium polyglutamate stock solution" without specifying the molecular weight.

Process Considerations: Products with fermentation origins and narrow molecular weight distribution (PDI < 1.5) are more stable. Leading companies like Shandong Freda have achieved medical device-grade raw material registration, ensuring higher quality.

Professional Choice: Sost Biotech – Your Source Partner for Sodium Polyglutamate powder
As a professional manufacturer with years of experience in bio-fermentation, Sost Biotech focuses on the research and large-scale production of high-quality sodium polyglutamate raw materials. We understand that the efficacy of an ingredient begins with the quality of its raw materials.

Our Core Advantages

Precisely Customized Molecular Weight: We offer a full range of products with molecular weights ranging from 100,000 to 2 million to ensure batch stability.

Complete Testing Reports: Each batch of products comes with an authoritative third-party testing report, ensuring verifiable product efficacy.

Leading Fermentation Technology: The entire production process leaves no chemical solvent residue, meeting COSMOS natural certification standards.

Application Technical Support: We have a professional team of formulators who can provide complete formulation solutions to help brands launch quickly.

Sost Biotech offers flexible supply from kilograms to tons, with free samples available for testing. We promise to rePGAnd to your inquiry within 24 hours and provide a complete technical information package within 48 hours.

Email:ericyang@xasost.com