There is a difference in expiry date and shelf life with about 6months of safety worked in.
This applies for most supplements and medicines.
Once you are more than 6 months over be carefull.
I LOVE "expired" protein powder, especially when I get it from GNC. That's the kind that GNC has to mark down in price.
Plus, if it's Gold Card Week, you get 20% off the marked-down price. That's how you can get 5-lb jugs of ON 100% Whey (Gold Standard) or 4-lb jugs of NITRO-TECH for $20, when they normally retail for $45-$50.
Right now, I have a big jug of GNC Mega Whey, which normally retails for $65. I got it for $28.
Another of my favorites are the "expired" RTDs, namely from ABB Nutrition. Marked down, I've purchased them for as little as $0.80 a piece. Same goes for IsoPure's RTDs. One product I really miss is the bottled RTDs of NITRO-TECH, in grape and fruit-punch flavors. About 4 years ago, I could get them for $4 for a 4-pack. They tasted a lot better than the canned ones, which are still around.
I don't see how you still have that protein powder. Normally, when I get my marked-down stuff, it's usually gone before the shelf-life date, even it's within a month after I buy it.