Like most women, we have a serious makeup addiction. With countless mascaras, blushes, and lipsticks in our arsenal, we often forget about a few at the bottom of our makeup bag. This however, is a big problem.

Makeup bags are breeding grounds for bacteria and old unused makeup is no different. Did you know that you should throw away your mascara after 3 months of use? If you were as surprised by this as we were you'll be even more shocked to find out that a few of your favorite products have very small shelf lives.

Click through the gallery above to see the best practices for when to toss and when to save your makeup.