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Lactobacillus Ferment

Well toleratedFermentskin conditioninghumectant

No meaningful concern for most people; irritation is possible but rare.

Also written as: Lactobacillus Ferment Filtrate · Probiotic ferment

What it is

Lactobacillus ferment is the product of fermenting a nutrient medium with Lactobacillus bacteria. It contains lactic acid, peptides and other metabolites - the live bacteria themselves are not present in the finished cosmetic. It is marketed as a "postbiotic" and used to support the skin's own microbial balance.

What it does well

  • Hydrates and may help support the skin barrier

    Fermentation metabolites are humectant and there is growing laboratory interest in microbiome-supporting effects, but robust independent human trials on cosmetic use remain limited.

    Limited evidence

Worth knowing

  • "Microbiome" claims outpace the evidence

    Marketing often implies a proven rebalancing of skin flora. The science is early-stage and finished-product effects are hard to attribute to the ferment alone.

    Matters most toAnyone paying a premium for microbiome positioning.

Where the EU stands

No specific restriction

Not listed in any Annex of the EU Cosmetics Regulation, so there is no specific concentration limit; it is still covered by the general safety assessment every cosmetic product must pass before sale.

Regulation (EC) No 1223/2009 - no annex entry · source ↗

Masks that contain Lactobacillus Ferment