Ingredient review

Fermented Soybean Filtrate

INCI: Aspergillus/Soybean Seed Ferment Filtrate

A gentle, fermented ingredient that helps hydrate and condition skin without irritation, ideal for sensitive and dry skin types.

beautyskincarehumectantskin conditioning

In plain English

This ingredient is made by fermenting soybeans with a type of fungus called Aspergillus. The fermentation process breaks down the soybeans into smaller, more skin-friendly components like amino acids and peptides. When applied to the skin, it helps attract and hold moisture, making the skin feel softer and smoother. It's a mild, non-irritating ingredient that works well in hydrating serums and moisturizers.

Quick decision guide

Useful, but context matters

Fermented Soybean Filtrate 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 Fermented Soybean Filtrate.
  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

A filtrate obtained from the fermentation of soybean seeds by the fungus Aspergillus, containing a complex mixture of amino acids, peptides, and other bioactive compounds.

How it works

The fermentation process breaks down soybean proteins into smaller peptides and amino acids, which can penetrate the skin's surface. These components act as humectants, drawing moisture into the skin, and also support the skin's natural barrier function by providing building blocks for collagen and elastin synthesis.

Pros

Gentle hydration

Provides moisture without stinging or irritation, making it safe for sensitive and compromised skin barriers.

Skin conditioning

The amino acids and peptides from fermentation help support skin's natural repair processes, improving texture over time.

Cons and cautions

Limited evidence

While promising, there are fewer peer-reviewed studies on this specific ferment compared to more established humectants like hyaluronic acid.

Potential allergen

Although fermentation reduces soy allergens, trace amounts may remain, so those with severe soy allergies should proceed with caution.

Best for

  • People with dry or dehydrated skin looking for a gentle humectant
  • Those with sensitive skin who react to stronger active ingredients

Use caution if

  • Individuals with a known soy allergy should patch test first, as trace proteins may remain

Usage tips

Apply after cleansing and before heavier creams to maximize absorption.
Layer with a moisturizer containing occlusives like shea butter to seal in the hydration.

Safety summary

Generally recognized as safe for topical use in cosmetics. Low irritation and comedogenic risk. Patch test recommended for those with soy allergies.

Research notes

Moderate evidence supports its hydrating and skin-conditioning benefits, largely from ingredient supplier studies and some independent research on fermented botanicals. More clinical studies are needed to compare directly with standard humectants.

Common label clues

Typical concentration
1-10% in leave-on products
Regulatory status
Approved as a cosmetic ingredient in the EU, US, and other major markets. Not regulated as a drug.
Common uses
Serums, Moisturizers, Essences, Toners
Environmental note
Soybean cultivation can have environmental impacts; look for products using non-GMO or sustainably sourced soy if concerned.

Good to know

  • Fermented ingredients are often more easily absorbed by the skin due to their smaller molecular size.
  • This ingredient is commonly found in K-beauty essences and serums for its gentle, hydrating properties.

Common questions

What is Fermented Soybean Filtrate in beauty products?

This ingredient is made by fermenting soybeans with a type of fungus called Aspergillus. The fermentation process breaks down the soybeans into smaller, more skin-friendly components like amino acids and peptides. When applied to the skin, it helps attract and hold moisture, making the skin feel softer and smoother. It's a mild, non-irritating ingredient that works well in hydrating serums and moisturizers.

What does Fermented Soybean Filtrate do in a beauty product?

The fermentation process breaks down soybean proteins into smaller peptides and amino acids, which can penetrate the skin's surface. These components act as humectants, drawing moisture into the skin, and also support the skin's natural barrier function by providing building blocks for collagen and elastin synthesis.

Is Fermented Soybean Filtrate safe for most people?

Generally recognized as safe for topical use in cosmetics. Low irritation and comedogenic risk. Patch test recommended for those with soy allergies.

Who should be careful with Fermented Soybean Filtrate?

Individuals with a known soy allergy should patch test first, as trace proteins may remain

Research sources

CosIng - European Commission ingredient databaseOpenPubMed - Fermented botanicals in skincareOpenINCIDecoder - Ingredient profileOpen

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.