Arterosil® HP is a proprietary blend of a rare seaweed and fruit and vegetable extracts to help support arterial and endothelial health.* The main bioactive component in Arterosil® HP is clinically researched rhamnan sulfate (as MonitumRS™), a polysaccharide (type of carbohydrate) extracted from a unique green seaweed, Monostroma nitidum, clinically shown to help support the integrity and function of the endothelial glycocalyx.