After a quick google, most sources seem to agree 1 year is the point where you should bin, unopened or not.
This is why (stolen from a beauty forum)-
All makeup products, even unopened have a shelf-life, i.e. a best-before date and to make matters worse, the actual shelf-life of any makeup product (opened or not) depends on how you store it. It is best to store your products in a dry, cool, dark place as the products ingredients (such as pigments) might react to UV light and bacteria thrive on heat and humidity.
The shelf-life depends on the type of product itself. e.g a powder eyeshadow will have a much longer shelf-life than say a moisturizer or a product containing SPF. This is due to the fact that products containing oil are more susceptible to bacterial growth over time
Just throw it out. Let go!