Kombucha-fermented red berry extracts showed higher levels of active compounds than non-fermented versions, with both proving non-toxic to skin cells in lab tests. Applied topically in a tonic formula, these ingredients improved skin hydration, reduced water loss, and helped balance pH—suggesting kombucha ferments could be a legitimate skincare ingredient, not just hype.

Researchers compared fermented and non-fermented red berry extracts using lab analysis to measure antioxidants and active compounds, tested them on human skin cells for safety, and conducted actual application tests on human skin to measure hydration and other benefits.

Funding not disclosed in abstract