TweetAccording to the labels it's good for 30 days unrefridged. I have no idea if you let it get hot for a week, then put it back in if it will still last 6 months or more, I don't take chances if I can avoid it. When it spoils, there IS no safe way, either take 10iu's and no carbs and see if you start going hypo, or much better idea, if you think it's bad or weak, throw it away, a new 1000iu vial is only $35 at most!