Start your year off right and update your stash of makeup products! All makeup products have a shelf life and can be a breeding ground for germs and bacteria. Generally makeup can last from its opened date up to 12-18 months. Products with water as its first ingredient have the shortest lifespan after opening, since the water encourages the growth of microbes. Products without much water, like eyeshadow or blushes, have a longer lifespan since there is nothing for bacteria to grow on. If any of your products are looking or smelling a bit funky, just give it a toss. Here are some tips and guidelines on when you should be throwing out your old makeup products.