Last updated: Mar 26, 2009
Your mascara from last summer? Time to toss it. That hot red lipstick you bought for New Year's Eve 2008? You probably shouldn't reapply. Just like the drugs in your medicine cabinet, your makeup has an expiration date. Here's our guide to what you should keep and when you should replace in.

Average life span: four to six months

Switch out your mascara every four to six months or as soon as it starts smelling funky (think: burning plastic) and depositing more clumps than color, says Jeannette Graf, MD, a dermatologist in Great Neck, New York. Take no chances with eye products—germ-ridden formulas can cause infections and sties. When you buy a new tube, do all you can to safeguard it from bacteria. Close it tightly after each use, avoid pumping the wand in and out, and never, ever share your mascara with anyone.

Average life span: one year

Immediately part ways with your pencil liner if the tip starts oozing an oily substance or forms a white film. Hang on to liquid liners for no more than six months, and dump them sooner if they thicken or smell like decaying roses. Theres little you can do to extend the life span of a liquid formula, since the applicators tip is in constant contact with your eyes and can quickly become a breeding ground for bacteria. But you can shave away germs on pencils by sharpening every few days.

Average life span: one year

Most formulas—liquids, creams, and compacts—can last up to a year if kept out of direct sunlight and away from heaters. But once your liquid starts to separate, your cream thickens, or your compact color develops a rubbery aroma, its time to toss it. To extend the life of your foundation, use a cotton swab when dipping into bottles. Use a compact? Wash the puff or sponge every few weeks.

Average life span: one year

If you use a pan or stick formula, youll know its gone bad when it cracks or turns tough and elastic-like. Its time to throw out your liquid concealer if it separates, appears oily, and/or smells rancid. Keeping hands out of your concealers pot or pan and tightly screwing on the lid can save it from spoiling before the year is up.

Blush and eye shadow
Average life span: one to two years

Expect creams to last one year, powders about two. If your powder grows a white crust or starts to crumble before that time, chuck it. “Creams tend to thicken and smell funny when they turn,” Dr. Graf says. Other makeup-life-extending tips apply, too—use cotton swabs, tighten lids, avoid heat and sunlight. You can also protect powders by keeping them dry and storing them in a place other than the bathroom, where humidity can alter their texture.

Average life span: eight months

Unless it turns gooey, smells rubbery, or no longer applies to your lips, you can safely use lipstick for at least eight months. Of course, if lipstick comes into contact with a cold sore or another type of infection, kiss it goodbye.

Makeup brushes
Average life span: a year or longer

Natural-hair brushes—the ones you use for powdered products—can last almost a lifetime, if taken care of. Wash them once a week with gentle soap and warm water, and then set them on a table to dry with the brush end hanging off the edge. Synthetic brushes, used for creams, last only about a year and need to be cleaned at least twice a week with an alcohol-based cleaner. Toss when they start shedding, become rigid, or stop applying color evenly.