If it was not too long ago, then u shood be fine.
Eg, say I buy something now and its epiration date is a year from now. I wood consume it till 1.5 years from now. I wood not consume it 2 years from now.
Nothing at all especially if the creatine looks like it should (a white powder). I am using expired creatine at the moment and had not suffered any ill effects.
What will happen if u take craetine or protein power 10 years from its expiry date? Or very very old oil? I dont think bacteria is a problem. It may taste like crap, but nay negative effecst?
My guess is that newly expired creatine (i.e. 6 mos to 1 yr) would simply be less effective. I wouldn't imagine there would be any serious reprecussion.
__________________ Age: 26 Height: 6'1" Weight: 160 lbs. Years Training: 8 Supps: protein powder, BCAAs, L-Glutamine, creatine, multi-vitamin