Insulin can become damaged and ineffective if it is not stored properly.
Always read the insulin package information that tells the best way to store your insulin.
You can keep open bottles with you if you keep them in a dark place. The bottles should not be exposed to temperatures below 36F or above 86F. Never leave insulin bottles in the sun or in your car.
Avoid shaking insulin bottles and cartridges too much to prevent loss of medication strength and to prevent clumping, frosting, or particles settling out. Follow the storage information provided by the manufacturer.
The first time you use an insulin bottle, write the date on the bottle label. Always store an extra bottle of each type of your insulin in the refrigerator.
WebMD Medical Reference from Healthwise