HMG-CoA reductase, Chinese name is hydroxymethyl glutaryl CoA reductase. It is the rate-limiting enzyme in the process of cholesterol biosynthesis in vivo, which can catalyze HMG-CoA to produce mevalonate, which is the rate-limiting step of cholesterol synthesis in vivo. HMG-CoA reductase is an important target of drugs for regulating blood lipid.

HMG-CoA reductase inhibitor has a similar structural fragment to HMG-CoA substrate, and its affinity is greater than HMG-CoA substrate, which can competitively inhibit HMG-CoA reductase from producing mevalonate, reduce cholesterol production and in vivo content, and help to lower cholesterol, especially low-density lipoprotein cholesterol. Low density lipoprotein cholesterol is the chief culprit of atherosclerosis. Lowering low-density lipoprotein cholesterol can slow down the progress of atherosclerotic diseases, thus preventing and treating cardiovascular and cerebrovascular diseases.

HMG-CoA is the rate-limiting enzyme of cholesterol synthesis. Lipids include fats and lipids, and cholesterol is a kind of lipids. Fatty acids and triglycerides are mainly synthesized in the liver. The raw materials for fatty acid synthesis are glucose, degraded fat and degradation products of certain amino acids. Fatty acids synthesized by the liver and fatty acids absorbed into the liver in the form of free fatty acids or lipoproteins in blood become triglycerides, phospholipids, cholesterol, etc. Acetphthalein-coa synthase and fatty acid synthase are key enzymes in the process of fat synthesis, and some factors affecting fatty acid synthesis are mainly realized by regulating the activities of these two enzymes. Insulin and thyroxine are the two most important hormones regulating lipid metabolism.