Tampon shelf life?

[glitterberrys.livejournal.com]

I probably should have asked this *before* using the tampon in question, but it didn't occur to me until just now...

Do tampons expire? This is a box that's been open for about three years (I came down with a nasty bout of BV not long after I bought said box and switched back to mostly pads only), hanging out under the sink. I'm not sure how damp it gets under there, but it seems like the kind of place that would, in fact, get somewhat damp. They're in their little plastic wrappers and seem fine, and the internet seems to suggest that they don't expire, but this seems a pretty long time.