What it is
Aphanothece Sacrum Exopolysaccharides, commonly called sacran, is a very large sulfated polysaccharide produced by a rare Japanese freshwater cyanobacterium traditionally cultivated as Suizenji nori. In cosmetics it is valued for its ability to bind water and form a smooth, conditioning film on the skin surface, contributing to a soft, hydrated feel. In sunscreens it is used as a sensory and moisturizing additive rather than as a UV filter.
Safety & warnings
As a large, inert polysaccharide it is generally well tolerated and is not associated with notable comedogenicity or fragrance-allergen concerns. People with specific sensitivities to algal or cyanobacterial materials should patch test, but reactions are uncommon.
Origin & sourcing
Natural; a biopolymer harvested from cultivated Aphanothece sacrum, a freshwater cyanobacterium (a type of nori) grown in spring-fed waters in Japan.
Questions everyone asks
What is sacran?
Sacran is the common name for this exopolysaccharide secreted by the Aphanothece sacrum cyanobacterium, used in skincare for hydration and a smooth film-forming feel.
Is it an active sunscreen ingredient?
No. It is a moisturizing, film-forming additive; UV protection comes from the dedicated filters in the formula.