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Other actives

Ferments and ferment lysates

Also listed as galactomyces ferment filtrate, saccharomyces ferment filtrate, bifida ferment lysate, lactobacillus ferment, yeast extract

Liquids left after yeast or bacteria ferment, sold as essences and 'probiotic' skincare. Hydrating; beyond that, evidence is small and mostly manufacturer-run.

Weak evidence

What it is

Ferment filtrates are the strained liquid from growing yeasts such as galactomyces or saccharomyces; lysates are broken-open, non-living bacteria such as bifida or lactobacillus. They contain amino acids, sugars, organic acids, vitamins and peptides that act as humectants and may support the skin barrier.

'Probiotic' skincare is a misnomer: these products don't contain live microbes. Whether lysates usefully shift the skin's own microbes is an open research question.

How strong is the evidence?

Weak evidence

Evidence comes mainly from lab studies and trials run by the companies that sell these ingredients. A double-blind trial of a 10% bifida lysate cream in 66 women with reactive skin found less sensitivity and dryness after two months. A 12-month study of galactomyces products reported fewer wrinkles and spots but had no control group and was run by the manufacturer.

What it's used for, checked

Hydration and smoother skin

Mixed

Humectant contents; improvements reported mostly in industry studies.

Calming sensitive skin (bifida lysate)

Mixed

One manufacturer-run placebo-controlled trial found less sensitivity.

Reversing skin aging

Unproven

The main galactomyces study had no control group.

Probiotic balancing of the skin microbiome

Unproven

No live microbes are present, and microbiome benefits aren't shown.

Who should be careful

  • Generally well tolerated.

The studies

Every citation is checked against its PubMed record.

  1. Bifidobacterium longum lysate, a new ingredient for reactive skin.
    Guéniche A, Bastien P, Ovigne JM, Kermici M, Courchay G, Chevalier V, et al. · Experimental Dermatology · 2010 · RCT

    66 women with reactive skin used a cream with 10% bifida lysate or a control cream twice daily for 2 months; the lysate group had less skin sensitivity, better barrier resistance and less dryness. Run by a cosmetics company.

  2. Significant Reversal of Facial Wrinkle, Pigmented Spot and Roughness by Daily Application of Galactomyces Ferment Filtrate-Containing Skin Products for 12 Months-An 11-Year Longitudinal Skin Aging Rejuvenation Study.
    Miyamoto K, Inoue Y, Yan X, Yagi S, Suda S, Furue M · Journal of Clinical Medicine · 2023 · Uncontrolled longitudinal study

    86 women used galactomyces ferment filtrate products twice daily for 12 months; hydration rose and wrinkle, spot and roughness measures improved from their 11-year decline. No control group; the authors were employees of or consultants to the manufacturer.