There are two main categories of insulins commonly used in clinical practice, both with different doses. Including ordinary insulin, which has a specification of 400 units of insulin in 10ml, 1ml contains 40 units. This part of insulin can be extracted with a 1ml syringe and injected subcutaneously, or added to a vial for intravenous drip to achieve the therapeutic effect of lowering blood sugar. It also includes the genetically recombinant human insulin currently in use. This type of insulin is designed with a pen test and needs to be injected into an insulin pen, which contains 300 units in 3ml. For this type of insulin, it cannot be injected by drawing with a 1ml syringe, but only by taking an insulin pen for injection. The above two types of insulins are the commonly used insulins, and the dosage forms are different, so the injection method and the injection dosage will be different.