We all have a favorite tube of lip gloss that we stock up on, but then there are those products that sit at the bottom of our purse and rarely see the light of day. So, are cosmetics still safe to use when you can't even remember how long ago you purchased them? Probably not. According to Byrdie, most products, whether it's drugstore or designer, have a pretty short shelf life.

While that might mean half of your beauty stash should be tossed in the trash, don't be too upset — you now have a legitimate excuse to go shopping! Scroll down to find out the typical lifespan of commonly used beauty products.

Mascara — 3 months

It's important to keep track of how long you've been using a mascara since it's used around the eyes, which can become easily infected. If the product has a funny smell or starts getting clumpy before you even apply it to your lashes, it's time to throw it out.

Lipstick and lip gloss — 1 year

Changes in color and texture are dead giveaways that your favorite ruby red has seen better days. If you notice a weird smell, toss it — it could mean that a fungus is growing.

Nail polish — 1 to 2 years

If the bottle's contents look separated or layered, give it a quick shake. If it still doesn't mix together properly, or the polish comes out thick and goopy, it's gone bad. It's also recommended that you store polishes away from heat and sunlight, as they can make the color fade quicker.

Face powder and blush — 2 years

All powders — whether it's a highlighter or a contour kit — naturally last longer than liquids. If you notice the product becoming dry or flaky, dump it.

Eyeshadow — 6 months

Though the majority of shadows are powders, their lifespan is shorter because you're using the product around the delicate eye area.

Foundation and concealer — 6 to 12 months

After a year, you'll probably notice that the product looks discolored or has started to separate — a clear indicator that it's past its prime.

Eyeliner — 3 to 12 months

While pencils are good for a year (each time you sharpen it, you're getting rid of a layer that could contain bacteria), gel and liquid formulas should be replaced every few months.