Does anyone know if the expiration dates on the bottom of the ProActiv bottles are really that relevant?

I have 2 full bottles of the cleanser that I refuse to throw away or stop using since they are not cheap, but at the same time, I'm wondering if after the expiration if the product has lost it's effectiveness. :(

I have a few expired bottles and I still use them. My mom refuses to throw them out too. I never noticed a difference.

I wouldnt worry about it too much unless its years out of date. I dont think its as crucial as medicine or sunscreen if they are expired. Why waste it? It should be still somewhat effective if you havent stored in a hot humid place.

I've used it past it's expiration date when I had the kits back up after being on auto-ship, and I never noticed any difference in the way it worked. Like squirrel said though, I wouldn't use it if it's years out of date, but otherwise, I think it'd be fine.

The bottles expired in Oct 2006. Is that too long ago?

Depends how you stored it but that might be a little old :)
I would think it wouldnt be as effective now but I would still use it cos I am frugal. The wash should still wash but some people think that having the effective ingredient in a wash is pointless because it gets rinsed away.

The bottles have been stored in my linen closet with the door shut at all times.

I think it should be fine. I store my stuff that way too. I find that as long as you dont open it or use it a bit and then store away the stuff lasts a bit longer.

I would dump products that are two years over the expiration date. The expiration date is there for a reason. ProActiv is an expensive product but it is not worth using something on your skin that may actually cause potential damage to it. I say throw them out and invest in a new bottle or something new. :)