Metformin is one of the most prescribed drugs on the market for patients with type 2 diabetes. It has three primary mechanisms of action that make it effective in treating patients. It decreases blood sugar production in the liver, which helps prevent hyperglycemia. Second, it increases the sensitivity of the cells responsible for processing insulin, which is part of why it is often an earlier step than prescribing insulin itself (although they are often prescribed together as well). Additionally, it decreases glucose absorption in the intestines. All three of these mechanisms of action together make it effective in regulating blood sugar and properly making use of insulin.