Oil Shelf Life

[danachevroletfor1967]

I have been wondering for a time now but just remembered finally to ask; the ol memory just isn't what it used to be. Does an unopened bottle of oil break down or degrade in any way if it is just sitting on a shelf in a basement where it is not exposed to sub freezing temps or too hot of temps? Is it safe to use to add to an engine to bring the level up to full if it has been sitting for say 4-5 years? What about if the bottle has been opened, some oil used, top reinstalled and sitting for 4-5 years? What do you guys think?