I don't know about potency, but you cold always donate/gift them to a shelter or rescue group. I volunteer at a nearby no-kill shelter, and we could always use more toys for the cats there. :-)

Thanks for the reply....I am thinking about doing exactly that!

I think the potency would be okay. I have this plastic container of catnip that must be about 10 years old by now. My cats still open the cabinet door and dig that thing out and play with it. One of them recently dragged it around for three minutes trying to get it open - captured on video.

Here is a link that might be useful: Proof that catnip lasts