Ancient Tea, Literally

I found out that there's  tea bag in a kitchen cabinet.  Still I am still recovering from my flu, and that I need something to smooth my throat, I used the tea bag to make a cup of tea.  I even added some lemon pieces in it.

Later I started to realize that the tea bag was something I left there years ago, probably 2 to 3 years.

So, is there expiration day on tea bags?

But then I am still alive after drinking that cup of tea.  So, whatever.  (It's like I am gradually training myself to live like a hobo.)