Depending on the source and purity, insulin preparations can be divided into animal insulins, human insulins and insulin analogues. According to the difference of action characteristics, insulins can be further divided into ultra-short-acting insulin analogues, regular (short-acting) insulins, medium-acting insulins, long-acting insulins (including long-acting insulin analogues) and premixed insulins (including premixed insulin analogues). The types and preparations of insulins commonly used in China at present are shown in the table and figure. Types of insulins commonly used in clinical practice and their preparations. Ultra-short-acting insulin preparations Short-acting insulin preparations Medium-acting insulin preparations Long-acting insulin preparations Premixed insulin preparations