I know many ladies who have held onto the same tube of mascara for over three years, just because they use it infrequently. FYI: just because something isn't used everyday doesn't mean that it's still okay to use after it's "expiration date".
Some products now bear tiny little icons like this to help you figure it out:
But a lot of them are super tiny (like the above picture) and many products don't even have them. So here's the inside scoop on how long you should keep each product.
Face Makeup
Toss-it time: Six months for liquids; two years for powdersInsider info: You increase the odds of bacterial growth — and, hence, of breakouts or irritation — when you repeatedly dip your brushes and fingers into liquid foundation. Also, as it ages, foundation can go on unevenly, creating a streaky, inconsistent finish. “Oils rise to the top, and the consistency thickens,” explains New York City makeup artist Mathew Nigara. Powders present less of a problem because bacteria can’t grow where there’s no water. However, over time, powders with botanical ingredients like aloe or jojoba can become harder to blend and are more likely to crumble, as their trace amounts of water evaporate.
Mascara
Toss-it time: Three monthsInsider info: “A mascara tube is a dark, wet environment — the perfect breeding ground for bacteria,” says New York City optometrist Andrea Thau, O.D. “Preservatives in a mascara only work for so long.” Dr. Thau knows from firsthand experience: She once developed a sty from a makeup artist’s mascara wand. Plus, three-month-old mascara is a nonperformer. “It’s chalky and powdery, and any lengthening or thickening fibers often separate from the fluid, so the mascara stops going on in a smooth, even coat,” says makeup artist Cristina Bartolucci. To avoid hastening the demise of your mascara, never pump the wand — that pushes air into the tube, causing it to dry out faster. Instead, slowly draw out and twist the brush to scrape the tube’s interior and pick up product.
Eyeliner and Eye Shadow
Toss-it time: Liquid eyeliners, three months; cream eye shadows, six months; pencil eyeliners and powder eye shadows, two yearsInsider info: As they do with mascara, bacteria tend to flourish in liquid-eyeliner tubes, and the product dries out. Pencil eyeliners have a longer shelf life because you can create a fresh, clean surface each time you sharpen them. (Just be sure to regularly sanitize your sharpener with rubbing alcohol.) Powder shadows, like pressed powders, are less prone to contamination because they, too, lack water (if you wet them, toss after six months). But aging eye shadows have performance issues: They get packed down, making it harder to pick up pigment with your brush, says Bartolucci.
Lipstick and Lipliner
Toss-it time: Lipstick and gloss, two years; lipliner, two years or moreInsider info: Lipsticks’ water content makes them potential mini reservoirs of bacteria. No surprise, they also dry out with age, says New York City makeup artist Tina Turnbow: “They no longer look creamy on the lips.” Long-wearing formulas may have an even shorter life span since they often contain ingredients that evaporate more quickly than creamier formulas. Pencil lipliners, like eyeliners, may last a little longer since putting them through a sharpener removes the old surface.
[info courtesy of Good Housekeeping]