insulin shelf life - from a Diabetes website
How Should I Store My Insulin?
Always keep two bottles of each type of your insulin on hand. The bottle that you are using may be stored at room temperature (not higher than 80 degrees F) for 30 days. Store it where it will not get too hot or too cold and keep it out of direct sun.
A good rule of thumb is that if the temperature is comfortable for you, the insulin is safe. Vials of insulin that you are using should also not be refrigerated.
However, extra bottles of insulin should be stored in the refrigerator (do not allow your insulin to freeze). The night before you are ready to use your new bottle, take it out of the refrigerator and allow it to warm to room temperature.
For insulin pens, check the package insert for storage instructions.
Always check your insulin bottle. Rapid acting and short acting insulin should be clear. Other forms of insulin should have a cloudy appearance yet be free of clumps.
If you are carrying your insulin with you, be careful not to shake it. Shaking or agitating the bottle creates air bubbles that can affect the amount of insulin you withdraw for an injection.