Whether the opened insulin will go bad if it is not placed in the refrigerator depends on the time of placement and the temperature. Normally, insulin that has been opened, i.e. is in use, can be stored at room temperature of 25°C for about 4 weeks. Unopened insulin can be stored at a constant 2-8°C until the shelf life on the box. The storage of insulin should avoid low temperatures to prevent freezing or excessive temperature fluctuations, which may affect the potency of insulin and lead to a weakening of its hypoglycemic effect. In addition, insulin in use does not need to be stored in the refrigerator. If you have to put it in the refrigerator, you should take it out of the refrigerator at least half an hour before the injection, put it at room temperature, and then inject it subcutaneously when it returns to room temperature. This is to prevent the irritation at the injection site from worsening, which may affect the absorption of insulin and lead to excessive blood sugar fluctuations.