Insulin must be kept in a refrigerator below 10℃, and the activity can be kept unchanged for 2~3 years in a refrigerator at a temperature of 2℃~8℃, even for insulin that has been partially aspirated for use. When it is used, it can be used in places where the temperature does not exceed 30℃ and greater than 2℃, but it must be kept away from sunlight to prevent failure. Insulin in use can be stored indoors in a cool place. Opened bottles of insulin in use can be kept in the freezer of the refrigerator for about 3 months. Do not put the in-use insulin refills back into the freezer together with the insulin pen, and keep them with you for 4 weeks. Cloudy insulin may form clumps if it is shaken for several hours or not stored properly, and should be discarded.