Succinoglycan

Succinoglycan is a high–molecular weight microbial polysaccharide used primarily as a rheology modifier/film-forming humectant, typically at low concentrations (about 0.1–1%). As a non-ionic, non-exfoliating polymer, it is generally well tolerated in patch testing and is not a common irritant or sensitizer compared with preservatives or fragranced components. Rare stinging or reactivity can still occur in highly compromised eczema skin due to individual intolerance or formulation context, but the ingredient itself is best classified as very gentle. Safety Notes: In consumer skincare, succinoglycan is typically used as a biopolymer film-former/humectant at very low levels (about 0.001–0.05%) in leave-on serums/creams and rinse-off cleansers to boost slip, hydration feel, and sensorial smoothness. Higher-end “biopolymer” or “microbiome/postbiotic” leave-on gels and masks sometimes use it as a primary texture/film-forming agent, with observed usage around 0.5–2.0% in OTC products; above this it becomes difficult to process due to viscosity/filming and is uncommon in mainstream retail. No specific EU/FDA maximum is set for succinoglycan as a cosmetic ingredient, so practical formulation constraints largely determine the upper end.