Ingredient review

Sodium Polygamma-Glutamate

INCI: SODIUM POLYGAMMA-GLUTAMATE

A powerful, natural humectant that holds more water than hyaluronic acid, making it a standout for dry or dehydrated skin.

beautyskincarehumectant

In plain English

Sodium polygamma-glutamate is a natural ingredient made by fermenting soybeans. It's a type of protein that acts like a sponge, pulling water into your skin and holding it there. It's often compared to hyaluronic acid, but it can hold even more moisture. Because it's gentle and non-irritating, it's great for sensitive or dry skin. You'll find it in serums, moisturizers, and sheet masks where deep hydration is the goal.

Review score

Safety, usefulness, and evidence

4.3Good
4.3/ 5

Strong fit for many routines

The evidence base is useful, but some claims depend heavily on the formula.

Risk flags are low for most users, though the finished product can still irritate.

Source
biotech
Evidence
moderate
Irritation
low
Clogging risk
low
How reviews are scored

Quick decision guide

Easy yes for most routines

Sodium Polygamma-Glutamate is generally a lower-concern ingredient when the full formula suits your skin.

Plain-English read

Treat this as a practical screening step before you compare products that contain this ingredient.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Sodium Polygamma-Glutamate.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.

Score terms in plain English

Irritation risk

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

Sodium polygamma-glutamate is the sodium salt of poly-gamma-glutamic acid, a natural polymer produced by fermentation of Bacillus subtilis (a type of bacteria found in soil and traditionally used in natto, a Japanese soybean dish). It is a large, water-loving molecule that forms a flexible film on the skin.

How it works

When applied to the skin, it forms a thin, invisible film that traps moisture and prevents water loss. Its long molecular chain can bind many water molecules, giving it a high water-holding capacity. This helps plump the skin, reduce the appearance of fine lines, and improve skin barrier function.

Pros

Superior hydration power

Sodium polygamma-glutamate can hold up to 5,000 times its weight in water, outperforming hyaluronic acid in some studies, which means more lasting moisture for your skin.

Gentle on sensitive skin

Unlike some active ingredients that can sting or irritate, this ingredient is very well-tolerated and can be used even on compromised or reactive skin without causing redness.

Cons and cautions

Potential tackiness

In higher concentrations or in formulas without proper texture modifiers, it can leave a slightly sticky or tacky feel on the skin, which may not be ideal for all users.

Less research history

While promising, sodium polygamma-glutamate has fewer long-term human studies compared to hyaluronic acid, so its full range of benefits and interactions are still being explored.

Best for

  • People with dry or dehydrated skin looking for intense moisture
  • Those with sensitive skin who react to other humectants

Use caution if

  • Anyone with a known allergy to fermented soy products (rare, but possible)

Usage tips

Apply to damp skin to maximize water binding and reduce any tacky feel.
Layer it under a moisturizer with occlusive ingredients (like shea butter or squalane) to seal in the hydration.
Use it in your morning routine for a plump, dewy look under makeup.

Safety summary

Sodium polygamma-glutamate is considered very safe for topical use. It has low irritation and sensitization potential. No significant safety concerns have been reported in cosmetic concentrations.

Research notes

Research shows it is an effective humectant with superior water-binding capacity. Studies indicate it can improve skin hydration and reduce fine lines. However, most studies are small or industry-funded, so more independent research is welcome.

Common label clues

Typical concentration
0.1% to 1%
Regulatory status
Generally recognized as safe for cosmetic use in the US and EU. No specific restrictions beyond standard cosmetic ingredient regulations.
Common uses
Serums, Moisturizers, Sheet masks, Eye creams
Environmental note
Produced via fermentation, which is a low-energy, renewable process. The ingredient is biodegradable, reducing environmental persistence.

Good to know

  • It is biodegradable and derived from renewable sources, making it a more sustainable choice compared to some synthetic humectants.
  • It is often used in 'clean beauty' formulations because of its natural fermentation origin.

Common questions

What is Sodium Polygamma-Glutamate in beauty products?

Sodium polygamma-glutamate is a natural ingredient made by fermenting soybeans. It's a type of protein that acts like a sponge, pulling water into your skin and holding it there. It's often compared to hyaluronic acid, but it can hold even more moisture. Because it's gentle and non-irritating, it's great for sensitive or dry skin. You'll find it in serums, moisturizers, and sheet masks where deep hydration is the goal.

What does Sodium Polygamma-Glutamate do in a beauty product?

When applied to the skin, it forms a thin, invisible film that traps moisture and prevents water loss. Its long molecular chain can bind many water molecules, giving it a high water-holding capacity. This helps plump the skin, reduce the appearance of fine lines, and improve skin barrier function.

Is Sodium Polygamma-Glutamate safe for most people?

Sodium polygamma-glutamate is considered very safe for topical use. It has low irritation and sensitization potential. No significant safety concerns have been reported in cosmetic concentrations.

Who should be careful with Sodium Polygamma-Glutamate?

Anyone with a known allergy to fermented soy products (rare, but possible)

Research sources

Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.