Lecithin is a phospholipid and is an essential component of every cell in the human body. Lecithin from soybean sources is a complex mixture of phosphatides. It is needed in the body for the structure of the cell membranes and for the protective sheath around the brain and the nervous system. Although lecithin is a fatty substance, it is also partly soluble in water and therefore acts as emulsifying agent. This emulsifying activity adds to the therapeutic activity of the phospholipid, assisting in the emulsification of cholesterol and fats in the blood stream and therefore helping to maintain normal, healthy cholesterol levels.