What Is Lactobacillus/Polysorbate 80 Ferment Filtrate?
Lactobacillus/Polysorbate 80 Ferment Filtrate is the clear liquid that remains after the probiotic bacterium Lactobacillus ferments polysorbate 80, an emulsifier originally sourced from vegetable oils and sorbitol. During fermentation the bacteria break down parts of the emulsifier and release a mix of peptides, organic acids and small molecules that create an environment hostile to unwanted microbes. The idea of using probiotic ferments in beauty products took off in the early 2000s when formulators looked for gentler alternatives to traditional preservatives. By harnessing well-studied food-grade bacteria they found a way to add both protection and a “biotech” marketing story to skincare.
Production starts with a purified batch of polysorbate 80 blended with water and nutrients. A Lactobacillus culture is introduced and allowed to ferment under controlled temperature and pH until the desired bioactive profile is reached. The mixture is then micro-filtered to remove the live bacteria, leaving a stable filtrate that can be added to cosmetics without regulatory concerns about live microbes.
You will most often spot this ingredient in leave-on and rinse-off products that need mild preservation: hydrating facial mists, sheet masks, lightweight serums, scalp tonics, baby lotions, natural-positioned moisturizers and post-shave balms. It pairs well with botanical extracts and other probiotic ferments, helping brands create preservative systems that feel more “skin friendly” on the label.
Lactobacillus/Polysorbate 80 Ferment Filtrate’s Cosmetic Benefits/Uses
Its main value in a formula comes from one key function.
Antimicrobial: The organic acids and peptides produced during fermentation inhibit the growth of bacteria, yeast and mold that could spoil a product. By adding this filtrate a formulator can extend shelf life, reduce the amount of harsher preservatives or build a complete natural preservative system. Because the active components are gentle and derived from food-grade fermentation they are usually well tolerated by sensitive skin and do not disturb the skin’s resident microbiome.
Who Can Use Lactobacillus/Polysorbate 80 Ferment Filtrate
This filtrate is generally suitable for all skin types including dry, oily, combination and sensitive because its antimicrobial action is gentle and it does not strip natural oils. People with very compromised or broken skin should still approach with caution since any product can sting when the barrier is damaged.
The ingredient is derived from plant based polysorbate and a food grade bacterium so it is considered vegan and vegetarian friendly. No animal derived materials are used in its production.
Current research shows no specific risks for pregnant or breastfeeding women when the filtrate is used in topical cosmetics. That said this is not medical advice and anyone who is expecting or nursing should check with a healthcare professional before adding new products to their routine.
Lactobacillus/Polysorbate 80 Ferment Filtrate does not increase photosensitivity so it will not make skin more prone to sunburn.
It can be used morning or night and layers well with common actives like niacinamide, hyaluronic acid and gentle plant extracts.
Potential Side Effects/Adverse Reactions
Reactions to topical Lactobacillus/Polysorbate 80 Ferment Filtrate vary from person to person. The points below cover potential side effects though most users experience none when the product is formulated and stored correctly.
- Mild redness or warmth: a temporary flush as skin adjusts to new ingredients
- Itching or stinging: more likely if the skin barrier is already irritated or compromised
- Allergic contact dermatitis: very rare but possible in individuals sensitive to components created during fermentation
- Eye irritation: if a product containing the filtrate accidentally gets into the eyes
If any discomfort or visible reaction occurs stop use immediately and consult a healthcare professional if symptoms persist or worsen.
Comedogenic Rating
Rating: 0 / 5
Lactobacillus/Polysorbate 80 Ferment Filtrate is water based and contains no fatty oils or waxes that could clog pores. Its antimicrobial peptides and organic acids are small molecules that rinse or absorb easily without forming an occlusive film. Because it leaves virtually no residue on the skin it is considered non comedogenic.
This makes the ingredient suitable for people who are prone to acne or frequent breakouts.
Formulators sometimes pair the filtrate with richer butters or oils to build a full preservative system. In that case check the other ingredients if you are sensitive to pore clogging compounds.
Summary
Lactobacillus/Polysorbate 80 Ferment Filtrate acts mainly as a gentle antimicrobial. During fermentation the Lactobacillus bacteria create organic acids and peptides that lower pH and disrupt the cell walls of spoilage microbes. When added to skincare these by-products keep formulas fresh so brands can cut back on harsher synthetic preservatives.
The ingredient is slowly gaining popularity, especially in probiotic themed and natural leaning products, though it is still less common than traditional preservative blends.
Safety data and everyday use show it is well tolerated by most skin types, including sensitive skin. As with any new cosmetic ingredient it is smart to patch test a small area first to be sure your skin agrees with it.