Supposedly insulin is no good 30 days after opening. So if you've used a pen, and it doesn't run out of insulin within 30 days, throw it away.I just started using Levemir on a daily basis. Although I've used only 2 of the 5 pens included in the package, my doc instructed to me to toss everything after 30 days. The expiration date on the package is 8/10/2010.
Does anyone understand this??