As much as we like to treat our favorite nude lipsticks and go-to eyeliners as LBDs—everlasting—that sadly isn’t the case. The moment you open the packaging, air seeps into your products and triggers the oxidation process, which causes changes in smell, texture, and even color.

That’s not the only problem, mind you. Over time, every tube and compact in your stash turns into a bacteria breeding ground. That bacteria can cause acne breakouts, irritation, and skin infections that will ruin a carefully-kept complexion—which is why you’ve got to toss the stuff the minute they go bad. Here’s a helpful calendar to bookmark!
Tip: Lipsticks and lip liners dry out when they’re expired (your matte lippies will get extra chalky!), while gloss becomes even stickier than usual.
Tip: Mascaras start to smell weird (almost like gasoline) once they go bad. Also, the formula will clump due to the air that’s constantly pumped into the tube whenever you remove or replace the wand. Never share mascara with anyone—it’ll make the bacteria levels go through the roof, exposing you to nasty eye infections!
Tip: You can tell your product is getting old when the color lightens or the formula starts to separate into layers.
Tip: Powder-based products get very dry, cakey, and flaky after the recommended shelf life has passed.
Tip: Check the color of your concealer: if it has darkened, lightened, or gone streaky, it’s probably way past its prime.
Tip: To give lip and cheek tints and multiple sticks a longer life, always use clean fingers during application. The texture will change more and more past the expiration date.
Tip: Although eye shadows are quite long-lasting, you must be vigilant about keeping your brush or sponge applicators clean. If not, you can cut down the shadow’s lifespan to as short as 6 months.
Tip: Liquid and gel eyeliners start to deteriorate after a very short period of time, so get as much wear out of them as you can! Once they go bad, these formulas will dry up (as usual), losing their ease of glide and intensity of color payoff.
Tip: Shake the bottle! A polish that is expired will settle into layers instead of blending back together. Also, if the lacquer has taken on a goopy, glue-like texture, it’s time to toss it.
Tip: You won’t have to worry about that expensive bottle you got last Christmas. It’ll keep for a decade if you store it in a cool, dark place. When perfume expires, the liquid in the bottle will lighten and the scent will change when you spritz it on.