Ingredient review
Fermented Soybean Extract
INCI: SACCHAROMYCES/SOYBEAN EXTRACT FILTRATE FERMENT
A gentle, yeast-fermented soybean extract that hydrates and supports skin barrier function with a low risk of irritation.
In plain English
This ingredient is made by feeding soybeans to a type of yeast (Saccharomyces, the same yeast used in baking and brewing). The yeast breaks down the soybeans into smaller, skin-friendly molecules like amino acids and peptides. When applied to the skin, these molecules help attract and hold moisture, and they may support the skin's natural repair processes. It's a mild, non-irritating ingredient often found in serums and moisturizers for all skin types.
Quick decision guide
Useful, but context matters
Fermented Soybean Extract 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.
- Step 1Start with the score, then check the irritation and clogging risk before judging Fermented Soybean Extract.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- 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
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
A fermented filtrate derived from soybeans (Glycine max) and Saccharomyces cerevisiae yeast. The fermentation process breaks down soybean proteins into smaller peptides and amino acids, which are then filtered to create a concentrated, water-soluble extract.
How it works
The small peptides and amino acids from the fermentation act as humectants, drawing water into the skin's outer layer. They also provide building blocks that may support the skin's natural barrier function and collagen production. The fermentation process may also generate additional beneficial compounds like vitamins and antioxidants that soothe and condition the skin.
Pros
Gentle hydration
Provides moisture without stickiness or irritation, making it suitable for sensitive and reactive skin types.
Barrier support
The amino acids and peptides may help strengthen the skin's natural barrier, reducing water loss over time.
Cons and cautions
Limited evidence
Most benefits are based on the known properties of its components (amino acids, peptides) rather than large-scale clinical trials on this exact ferment.
Variable potency
The quality and concentration of active peptides can vary between manufacturers, so not all products with this ingredient will perform the same.
Best for
- People with dry or dehydrated skin looking for gentle hydration
- Those with sensitive or reactive skin who want a mild conditioning ingredient
- Anyone interested in fermented skincare ingredients for added peptide benefits
Use caution if
- Individuals with a known soy allergy (though the fermentation process may reduce allergenic proteins, caution is advised)
Usage tips
Safety summary
Considered safe for topical use in cosmetics. The fermentation process reduces the presence of common soy allergens, but individuals with severe soy allergies should patch test first. No significant irritation or comedogenic concerns reported.
Research notes
Research on Saccharomyces/soybean ferment filtrate is limited. However, studies on fermented soybean extracts and yeast-derived peptides suggest potential for skin hydration, barrier repair, and antioxidant activity. More human clinical trials are needed to confirm specific benefits.
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. No specific restrictions beyond general cosmetic safety requirements.
- Common uses
- Serums, Moisturizers, Essences, Sheet masks
- Environmental note
- Soybean farming can have environmental impacts such as deforestation and water use. Look for products that source soybeans sustainably or from certified organic farms.
Good to know
- Fermented ingredients are often touted for having smaller molecular sizes, which may help them penetrate the skin more easily, though this is not always proven.
- This ingredient is vegan-friendly and cruelty-free as it is produced via fermentation without animal-derived components.
Common questions
What is Fermented Soybean Extract in beauty products?
This ingredient is made by feeding soybeans to a type of yeast (Saccharomyces, the same yeast used in baking and brewing). The yeast breaks down the soybeans into smaller, skin-friendly molecules like amino acids and peptides. When applied to the skin, these molecules help attract and hold moisture, and they may support the skin's natural repair processes. It's a mild, non-irritating ingredient often found in serums and moisturizers for all skin types.
What does Fermented Soybean Extract do in a beauty product?
The small peptides and amino acids from the fermentation act as humectants, drawing water into the skin's outer layer. They also provide building blocks that may support the skin's natural barrier function and collagen production. The fermentation process may also generate additional beneficial compounds like vitamins and antioxidants that soothe and condition the skin.
Is Fermented Soybean Extract safe for most people?
Considered safe for topical use in cosmetics. The fermentation process reduces the presence of common soy allergens, but individuals with severe soy allergies should patch test first. No significant irritation or comedogenic concerns reported.
Who should be careful with Fermented Soybean Extract?
Individuals with a known soy allergy (though the fermentation process may reduce allergenic proteins, caution is advised)
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.