Protein Powder Expiration Date

I was wondering if anyone knows if GNC whey protein powder is any good after its expiration date. Specifically if its safe and if it is still effective after it has passed its expiration date. If so, how long afterwards?

Thanks!

I think, that like medicines; once something reaches expire date it doesn’t immediately become toxic. But rather, it’s potency goes down?

But as for protein i have no idea man.

Oh btw, if GNC have expired whey protein powder i guess its telling us that they either over stocked, or people are buying from somewhere else. =P