Lactobacillus
Non-living lactic acid bacteria in cosmetics: heat-killed cells, lysates or ferment filtrates of different strains. Results depend on strain and form. In acne, one filtrate matched 2.5% benzoyl peroxide in a trial without a placebo group. In atopic dermatitis, no placebo-controlled benefit has been shown
Evidence by route
Topical application
The data are mixed and depend on strain and form. In acne, an L. paracasei filtrate matched 2.5% benzoyl peroxide in one trial without a placebo group. In atopic dermatitis, a small placebo-controlled pilot of a lysate found no effect. The rest are manufacturer studies without a described control group
- Sathikulpakdee S et al. Efficacy of probiotic-derived lotion from Lactobacillus paracasei MSMC 39-1 in mild to moderate acne vulgaris, randomized controlled trial. J Cosmet Dermatol. 2022;21(10):5092-5097. PMID 35384257
- Salo V et al. Topical probiotic Lactobacillus lactis treatment in atopic dermatitis: a placebo-controlled pilot study on tolerability and efficacy. Front Med (Lausanne). 2026;13:1694229. PMID 41709889
- Blanchet-Réthoré S et al. Effect of a lotion containing the heat-treated probiotic strain Lactobacillus johnsonii NCC 533 on Staphylococcus aureus colonization in atopic dermatitis. Clin Cosmet Investig Dermatol. 2017;10:249-257. PMID 28721083
- Muizzuddin N et al. Physiological effect of a probiotic on skin. J Cosmet Sci. 2012;63(6):385-95. PMID 23286870
- Cui H et al. Effects of a lotion containing probiotic ferment lysate as the main functional ingredient on enhancing skin barrier: a randomized, self-control study. Sci Rep. 2023;13(1):16879. PMID 37803101
- Cui H et al. Research on the anti-aging efficacy of fermented lysate VHProbi® MixA as the functional skincare ingredient. J Appl Microbiol. 2024;135(1). PMID 37977853
- Abedin ZU et al. Lactobacillus-Based Microbiome Therapy for Acne Vulgaris: A GRADE Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Cosmet Dermatol. 2026;25(3):e70792. PMID 41853869
How to read tiers A–F
- CWeak evidence. In vitro data, open-label studies, or expert consensus
Tolerability and safety
- Working concentrations
- There is no single working concentration, because the INCI covers different strains and forms. In a cosmetics company study of undisclosed design, 5% L. plantarum extract reduced acne lesion size and 1% did not (Muizzuddin 2012). An L. lactis lysate cream at 3–30% did not differ from placebo in atopic dermatitis (Salo 2026)
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Unknown
- Suitable for
- Normal, Dry, Combination, Oily, Sensitive
About this ingredient
Under the INCI name Lactobacillus, cosmetics contain non-living lactic acid bacteria of different strains in different forms: heat-killed cells (tyndallized), lysates or cell-free ferment filtrates. Results depend on strain and form. The INCI name alone does not say what is in the product. In acne, a randomized trial of 104 patients compared a lotion based on a filtrate of L. paracasei MSMC 39-1 with 2.5% benzoyl peroxide. Over four weeks, inflammatory lesions and redness fell equally in both groups, and comedones did not change. The trial had no placebo group (Sathikulpakdee 2022). A meta-analysis of five RCTs (332 people, oral and topical forms pooled) found no difference from placebo or benzoyl peroxide (Abedin 2026). In atopic dermatitis, an L. lactis lysate cream at 3–30% did not differ from placebo, but the pilot had only 13 patients (Salo 2026). In an open manufacturer study of 31 patients, heat-killed L. johnsonii lowered S. aureus load along with local SCORAD (Blanchet-Réthoré 2017). Manufacturer studies of lysate mixtures without a control group report improvements against baseline only (Cui 2023, Cui 2024). No placebo-controlled RCT of a topical form has shown a benefit. In the acne trial, side effects occurred in 7.69% with the lotion vs 26.92% with benzoyl peroxide. There are no data on use during pregnancy and breastfeeding.
Frequently asked questions
Is Lactobacillus safe during pregnancy?
Safety data for Lactobacillus during pregnancy is insufficient. Best avoided when in doubt.
What skin types is Lactobacillus for?
Lactobacillus suits: normal, dry, combination, oily, sensitive.
What is Lactobacillus and what does it do in cosmetics?
Non-living lactic acid bacteria in cosmetics: heat-killed cells, lysates or ferment filtrates of different strains.
Is Lactobacillus comedogenic?
On the Fulton scale 0/5 – non-comedogenic. For acne-prone skin, a rating of 3 or higher suggests choosing an alternative.
What's the INCI name for Lactobacillus?
The INCI name is Lactobacillus. It may also appear as: Inactivated Lactobacillus, Lactobacillus Ferment.
What concentration of Lactobacillus is effective?
There is no single working concentration, because the INCI covers different strains and forms. In a cosmetics company study of undisclosed design, 5% L. plantarum extract reduced acne lesion size and 1% did not (Muizzuddin 2012). An L. lactis lysate cream at 3–30% did not differ from placebo in atopic dermatitis (Salo 2026)
See Lactobacillus in a product composition right on the store page
The Evigrade extension adds an evidence panel to iHerb, Sephora, Druni and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
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