I have a bottle of tribex dated 7/03. I also have a bottle of M dated 11/03. Neither are opened. On this note I still have a half of bottle of mag10 which is dated 1/05. Can I still use them?
Personally I would use them. If you are worried, give customer service a call and they should be able to tell you if there is any effect to using them if they are expired.
Hope that helps,