Mascara: Mascara usually lasts 2-3 months. Depending on how much you use your mascara they might last a little less or a little longer, however the expiration date is about 2-3 months. Since you use mascara on your lashes and essentially around your eyes it’s more susceptible to harboring bacteria. And usually people pump their mascara brush into the tube which adds air and bacteria into it as well as dries it out.
Liquid Eyeliner, Foundation, and Concealer: These last about 6 months to a year. After that they can dry out and again can put bacteria and germs back into your skin which is NOT good. Liquid eyeliner can dry out quicker especially if it’s a marker. Sometimes you might not even notice if you don’t put the cap back on right as well. Eye Creams and serums usually last around this time as well.
Some products that last a bit longer are lip gloss, cream eyeshadows, face cream, sunscreen, and eyebrow gel. These last around 1-1.5 years.
The second longest lasting products are lip/eye liners, lipsticks, nail polishes, and powder foundation. These generally can last up to 2 years without expiring. This is great because some lipsticks can be expensive and powder foundation is a great product to keep around all the time!
Makeup products themselves don’t last longer than 3 years. Some products that do however are shampoor/conditioner, some lotions (usually ones in pumps, some in tubes might start to separate and become gross) perfumes and hairspray.