Mascara — Three Months
Since the action of taking the brush in and out of the tube increases the amount of bacteria introduced to the product, mascara tends to have a relatively short shelf life. Said bacteria is nothing to sneeze at: "When you use makeup after the expiration date, you are exposing yourself to bacterial overgrowth, contamination, infection and other toxins," says Stoj. Besides, you'll also likely notice the formula growing clumpier and more difficult to use over time, which definitely makes your decision to ditch your favorite tube a little easier.
Image via @toofaced
Liquid and Gel Eyeliner — Three Months
Like mascara, liquid and gel eyeliners can get a lot of bacteria mixed into their formulas through their mode of use, which means you should toss them sooner rather than later. There's also the practical side to it: even with careful storage, it's tough to find a liquid liner that'll keep from drying out longer than the prerequisite three months.
Image via @stilacosmetics
Foundation — One Year
Over time, foundations can change color or start to separate, two easy-to-catch expiration warning signs that Purdue says to keep an eye out for. She also notes that you're going to want to take special care with any foundations that don't come with a pump, as your fingers can contaminate the product, causing it to go bad faster.
Image via @fentybeauty
Lip Gloss — One Year
Sadly, lip glosses don't exactly last as long as you'd hope, which means you should probably toss that limited edition MAC Lip Glass you've been hoarding since high school. "I would throw out a lip gloss before a lipstick because you are pumping air and bacteria back into the lip gloss with the wand," explains Stoj.
Image via @covergirl
Cream Shadow, Blush, Foundation and Concealer — One to Two Years
As for cream products, they can last up to around two years, especially if you keep whatever tools you use to dip into them (brushes, puffs, makeup sponges, etc.) clean. Also, it happens to be pretty easy to tell when to get rid of them: They can start to smell a little, well, rancid. "If a cream product's smell changes, it's time to throw it out," says Stoj.
Image via @onomiebeauty
