Lecithin can be obtained from soybean, corn, and egg yolks. Although Lecithin includes diglycerides of stearic, palmitic and oleic acids, the exact fatty acid composition of Lecithin varies depending on the source from which it was obtained. Lecithin is used in the formulation of a large number of cosmetics and personal care products. It helps to form emulsions by reducing the surface tension of the substances to be emulsified. In general emulsifiers are molecules that have at least 2 distinct sides, (typically) one side that is compatible with water, and one side that is compatible with oils. They are added to cosmetic products to enable the mix of non-mixable liquids to make them compatible and keep them stable over time.