Can you use expired nicotine gum?

Yes: Most expiration dates are not all that accurate. It is not like a medicine is fine one day and the next day it suddenly goes bad. If it's just a few months past the expiration date it's probably perfectly fine. If it is way past it may not be quite as potent as it once was but it will not be dangerous. Try it and see. It will certainly be WAY safer than smoking cigarettes, which are deadly poison!