Important roles of insulin injection: First, lowering blood sugar. Insulin is a hormone secreted by human pancreatic islet cells to lower blood sugar, through the artificial synthesis of many short-acting insulin, medium-acting insulin, mixed insulin, long-acting insulin, through subcutaneous injection, are used to treat diabetes. Secondly, insulin can also be placed in liquid drops to achieve the therapeutic effect of rapidly lowering blood sugar. Third, insulin’s can also be used topically as well. By spraying a certain concentration of insulin on the wound that does not heal for a long time, it has the effect of promoting protein and fat synthesis, which can make the wound heal as soon as possible in a relatively short period of time, and the above is the main role of insulin.