a epipen ! yep in case someone has a sever allergic attack ! My son is very allergic to many things, a long list actually. so I got a hold of his doctor right away and he sent in a script for 2 pens. I was thrilled since when things go bad, there is no way to get treatment. Im so glad I got them, and I plan to refill the script and get 2 more in 6 months if things are still ok. I think it is important to cover all bases and as of right now, I have now 2 years worth of Zyrtec, benyadryl all ointments for bites, and rashes etc. Im covered for allergy's for a long time .
if outdated 2 years, if not well you have that date and up to a year, but if you keep it out ofg sun and different temperatures its less likely to turn brown and of no use. I had one that was 5 years past and still good. but I would say no more then 3 if in the dark and no temp changes.