My doctor told me that too. Said don't even try to use them past the expiration date. They won't work.I am not sure that I agree with the "it doesn't work after a year" (and yes, that is what it says on the box.... but still)
I need to research that though.....
I tell ya, if one of us has an anaphylactic reaction to a wasp or hornet, It's November and the epi pens we have on hand say they expired in October. I sure am going to try it.