Arterosil (Endothelial Glycocalyx Support)

Reviewed Sep 5, 2026

The active ingredient in Arterosil is rhamnan sulfate, a sulfated polysaccharide from the green seaweed Monostroma nitidum that is being studied for its effects on the endothelial glycocalyx, the protective inner lining of blood vessels. The strongest current evidence is mechanistic and preclinical. In cultured endothelial cells, rhamnan sulfate strengthened the vascular barrier and reduced the passage of LDL across the endothelial layer by roughly 4-fold (and by up to 8-fold across the sub-endothelial matrix), even in the presence of glycocalyx-degrading enzymes; it also bound the inflammatory regulator NF-κB and the growth factors FGF-2 and PDGF-BB with high affinity and blunted NF-κB-driven inflammation (Biomaterials, 2022). In ApoE-deficient mice on a high-fat diet, oral rhamnan sulfate reduced whole-aorta atherosclerotic lipid deposition by about 45% in females and 36% in males and lowered plasma cholesterol (Biomaterials, 2022; Cells, 2023), and in other rodent models it helped preserve the glycocalyx and its component syndecan-4 while reducing vascular inflammation (Marine Drugs, 2022). Human data remain very limited: a small, uncontrolled case series of 6 patients reported a statistically significant average reduction of 5.55 mm in total carotid plaque burden after 6 months of a rhamnan sulfate supplement added to an already-optimized prevention program (Integrative Medicine, 2023). More recent work continues to explore glycocalyx repair in injury models (Intensive Care Medicine Experimental, 2026) and metabolic and cognitive endpoints (Marine Drugs, 2025). Overall the evidence is early, dominated by laboratory and animal studies with only preliminary, uncontrolled human data, so findings should be interpreted cautiously. Arterosil is a dietary supplement, not a drug, and is not intended to diagnose, treat, cure, or prevent any disease. Discuss use with your physician, especially if you take blood thinners.