Lecithin is useful as an adjunctive treatment for diseases such as fatty liver and atherosclerosis. The main role of lecithin is phosphatidylcholine, phosphatidylcholine is the raw material for synthesizing lipoprotein, lipoprotein is the operation form of fat, which can make the intrahepatic fat transported to the outside of the liver, and participate in the body’s fat metabolism, which is useful for the prevention and treatment of fatty liver. At the same time, phosphatidylcholine can also reduce serum cholesterol, triacylglycerol, so that high-density lipoprotein increases, low-density lipoprotein decreases, atherosclerosis prevention and treatment. At the same time, phosphatidylcholine as a prerequisite for acetylcholine, can increase the production of acetylcholine in the brain, excitation of cholinergic neurons, brain cell function recovery effect. It is important to note that lecithin, primarily used as an adjunct to other lipid-regulating drugs, is not usually used as a stand-alone lipid-lowering drug. Lecithin is mainly extracted from eggs, patients allergic to eggs should be used with caution, in addition to the need to follow the doctor’s instructions to avoid overdose.