What it is
Yeast Polysaccharide refers to carbohydrate polymers—primarily beta-glucan and mannan—extracted from the cell walls of yeast (typically Saccharomyces cerevisiae). In cosmetic formulations it forms a moisture-retaining film on the skin surface through hydrogen bonding with water molecules, helping to increase stratum corneum hydration and reduce surface roughness. It also exhibits antioxidant and mild anti-inflammatory properties. Concentration of use in leave-on face products reaches up to approximately 0.36%. It is reported to provide a temporary visible tightening effect that improves skin texture. The ingredient is used in a small proportion of cosmetic products globally.
Safety & warnings
Saccharomyces cerevisiae is classified by the FDA as GRAS. Cosmetic safety testing of yeast-derived formulations has shown no detectable skin irritation in healthy individuals. Individuals with known yeast or mold allergies should patch test before use. No significant comedogenicity or photosensitivity concerns are reported at typical use concentrations.
Origin & sourcing
Obtained from the cell walls of yeast, most commonly Saccharomyces cerevisiae (baker's/brewer's yeast). Cell walls are isolated after fermentation, then processed through enzymatic or physical extraction methods to yield the polysaccharide fraction composed mainly of beta-(1,3)/(1,6)-glucans and mannans. The resulting material may be further purified and dried into a powder for cosmetic use.
History
Yeast cell wall polysaccharides have been studied since the 1940s for their immune-modulating properties. Beta-glucan from yeast was recognized by the FDA as generally safe (GRAS) for the source organism Saccharomyces. Regulatory bodies including the EU CosIng and the US CIR have reviewed yeast-derived ingredients; the CIR Safety Assessment covers the broader yeast ingredient class and supports their safe use in cosmetics at current concentrations.
Questions everyone asks
What exactly is Yeast Polysaccharide and where does it come from?
Yeast Polysaccharide is a mixture of complex carbohydrates—mainly beta-glucan and mannan—isolated from the cell walls of yeast, most commonly Saccharomyces cerevisiae. The yeast is fermented, and the cell wall fraction is extracted to yield these polysaccharides.
What does Yeast Polysaccharide do for the skin?
It acts primarily as a skin conditioner and film-forming agent. It helps retain moisture in the skin, may reduce the appearance of fine lines temporarily, and provides mild antioxidant and skin-protecting benefits.
Is Yeast Polysaccharide safe to use?
Yes, it is considered safe for cosmetic use at the concentrations found in personal care products. Saccharomyces cerevisiae is recognized as GRAS by the FDA. Sensitivity testing in clinical formulations showed no irritation in healthy subjects, though those with yeast allergies should exercise cauti
How does Yeast Polysaccharide differ from other yeast-derived ingredients like Yeast Extract?
Yeast Extract is a broader mixture containing proteins, amino acids, vitamins, and polysaccharides. Yeast Polysaccharide (or Yeast Polysaccharides) refers specifically to the carbohydrate fraction—beta-glucan and mannan—which is responsible mainly for film-forming, moisturizing, and skin-conditionin