What is it?
Lactobacillus is a group of lactic acid bacteria, the kind used in many fermented foods. On a cosmetic label, the name means the product contains material from one or more Lactobacillus species, which the EU inventory lists as a skin-conditioning agent. Despite “probiotic” marketing, a review of such cosmetics found that most contain ferments, lysates or filtrates of the bacteria rather than living cells.
Key information
- The EU cosmetic ingredient inventory defines Lactobacillus as one or more species of the microorganism Lactobacillus and lists it as a skin-conditioning agent.
- In 2025 the CIR Expert Panel concluded that four Lactobacillus ferment ingredients are safe as used in cosmetics; the plain name Lactobacillus was not part of that review.
- Cosmetics are expected to have very low counts of live microorganisms, which makes living probiotics hard to keep in a preserved product.
More information
The EU’s CosIng inventory defines the cosmetic ingredient Lactobacillus simply as “one or more species of the microorganism, Lactobacillus,” used for skin conditioning, and sets no restrictions on it. Related names you may see include Lactobacillus Ferment, Lactobacillus Ferment Lysate and Lactobacillus Ferment Filtrate, which describe what is left when the bacteria are grown and then processed.
Are the bacteria alive? A 2021 review of “probiotic” cosmetics found that most products contained ferments, lysates or filtrates, meaning no live microorganisms. The authors explained that water and preservatives make it hard to keep bacteria alive, and that cosmetics are expected to have low microbial counts, below 500 colony-forming units per gram for eye-area products and 1,000 for others. Non-living bacterial products like these are often called postbiotics.
The Cosmetic Ingredient Review (CIR) Expert Panel assessed four Lactobacillus ferment ingredients in a final report released in October 2025 and concluded they are safe in cosmetics in the present practices of use and concentration. It noted that these ingredients consist mainly of fermentation byproducts, such as lactic acid, peptides and polysaccharides, along with fragments of dead bacteria. Lactobacillus Ferment was used at up to 5.6 percent in leave-on products, and patch tests in people found no irritation or allergic reactions. The panel noted a possible skin-lightening effect and said products should be formulated so this does not occur. The plain name Lactobacillus was not included in that review.
On labels, “probiotic” is a marketing word, and it does not tell you whether any bacteria in the product are alive.
Sources: European Commission CosIng: Lactobacillus; Cosmetic Ingredient Review: Safety assessment of Lactobacillus ferment ingredients as used in cosmetics (final report, 2025); Molecules (2021): Probiotics in cosmetic and personal care products, trends and challenges
