Why does the Novolog Flexpen need to be discarded after 28 days? What are the possible effects if I?

3 Feb 2011

Generally a pen is not kept refridgerated. Insulin can stay active in a pen, unrefridgerated, for about 28 days. After 28 days the insulin begins to break down and not work as well. Insulin is usually kept in the fridge but small amounts, like what is contained in a pen, can be left at room temp but only for short periods of time. That is why they say to discard after 28 days. If you are not using most of the insulin contained in the pen and are throwing away most of it, talk to your prescriber and ask him the best course of action.