How Germy Is Your Makeup?

Maybe it's your favorite shade of eyeshadow or blush, a seemingly-endless bottle of moisturizer, or a killer lipstick you only use sparingly -- whatever the reason, we all have at least one makeup product we hold onto ... for far too long.

You probably know to be skeptical of a discolored foundation or a dried-out tube of mascara, but do you know the general shelf-life of your cosmetics? If your makeup has dried up, smells strange or generally looks off, it may have become a bacteria feeding ground. Jeffrey Benabio, M.D., a Kaiser Permanente dermatologist in San Diego tells The Huffington Post that all kinds of bacteria, viruses and fungi can make a home out of your beauty products.

Makeup can also go bad, says Dr. Benabio, a spokesperson for the American Academy of Dermatology. "Some of the more natural makeups that don't have preservatives are prone to spoiling," he explains, but those searching for all-natural cosmetics or products for sensitive skin often want to avoid those same preservatives. "It's a trade-off that we all have to make," says Dr. Benabio.

The best thing you can do to prevent both germy growth and spoiling makeup is to take better care of your products. Just like with sunscreen, products exposed to high heat or direct sunlight -- say, if you left your makeup bag in your car -- need to be tossed sooner, says Dr. Benabio. You'll also want to keep containers and bottles closed tightly, as exposing active ingredients, like vitamins and antioxidants, to the air can cause oxidation, the same process that turns a sliced apple brown, he explains. "It's not that it's spoiled, but it's not going to help you at that point, it's used up its potency," he says. Last but not least, don't store makeup in the bathroom, where heat and humidity encourage all sorts of icky growth. "Take a look in your shower," says Dr. Benabio. "That can grow in your makeup, too."

Assuming you follow the rules of proper care, how long will your favorite beauty products last? Click through the slideshow below to find out when it's time to toss your makeup and the health risks of hanging on to it too long.

Makeup Germs