Never thrown one out either. Most insulins I use up before or arround 1 month. I've only been concerned with Lantus. with it's short shelf-life that I remember getting in a big 10mL tallboy. I went way after day 28 (months even?) Never noticed a problem I could relate to it, but it was always on my mind.
Glad you started this discussions, as I'm feeling more comfortable being "non-compliant".
Glad to hear I’m not alone on this. So here is a follow up question. I seem to be noticing a trend that as my lantus gets near and beyond the 28 day “useful life” it actually seems to get stronger. I’ve observed the same lantus dose I use for the first few weeks if the lantus pen actually driving me lower than ideal during the next few weeks. I suppose its most likely coincidence or other variables at work, but is it possible for the lantus to actually gain potency as it ages?