i have had type 1 diabetes for 10 years. once i open it i dont keep it in the fridge, i have used insulin that has been out for months. just make sure it looks ok. i use the insulin pen but i'm sure its the same. i'd keep it in the fridge but if you forget for a little its fine
Its my understanding that slin will get a yellowish tint if it goes bad. I usually load up a pin for the week and keep it in my gym bag with no issues.