Cardiovascular Health Supports Healthy Cholesterol Levels Already Within The Normal Range With CardioAid-S Plant Sterol Esters Plus Added Fish Oil A Dietary Supplement General Health Family Owned Since 1968 GMP Quality Assured CardioAid-S Plant Sterol Esters is a combination of the ester forms of Beta-Sitosterol, Campesterol and Stigmasterol. Plant Sterols are plant-derived compounds that are structurally similar to cholesterol so that they help to limit absorption of cholesterol from the digestive tract. In this way, CardioAid-S can help to maintain cholesterol levels already within the normal range.