How long does your makeup last?

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Q: I have some makeup that I bought years ago. Is it still good? How do you know how long makeup will last?

A: After awhile, the ingredients in your makeup will begin to break down; your foundation will separate, your mascara will start to flake and your eyeliner will become dry.

Most experts will tell you that you need to toss the makeup as soon as it starts to discolor or smell funky, or when it cannot perform the purpose you bought it for. These rules apply to both the expensive brands and those you buy at the drugstore.

Most makeups contain the same basic ingredients, but few have expiration dates.

As a general rule, if you can’t remember how long ago you bought the makeup, toss it.

You’ll want to discard old makeup and applicators (like brushes and sponges) because they become full of bacteria. You can keep them from spreading germs by regularly cleaning them with a gentle soap and then setting them flat on a towel to dry.

If you get an eye infection, get rid of all your makeup that touched the eye area.

Makeup guidelines

To give you a general idea of how long your makeup will last, the experts at About.com, LifeTips and eHow offer some advice:

• Foundation: Water-based foundation will last up to a year and oil-based foundation will last 18 months. You’ll know it’s bad if it becomes off-color and smells sour.

• Concealer: Lasts up to one year, but throw it out if it looks cakey when applied.

• Powder: Loose powder will last up to two years, but compact powder will start to break down sooner due to the oils in your skin. To avoid this problem with compact powder, use a brush instead of a sponge when applying.

• Eyeliner: Lasts three years when sharpened regularly. If it’s dry, it will tug at your eyelid, so discard it.

• Eye shadow: Lasts three years; just keep those brushes clean.

• Eyelash curler: Lasts until the pad gets dirty or caked with mascara.

• Mascara: Lasts three to four months, but throw it away as soon as it starts to clump, flake or irritate your eyes. Oxygen is mascara’s enemy, so when applying, swivel the stick inside the container instead of pumping it up and down.

• Lip liner: Lasts three years, or until it dries out.

• Lipstick: Lasts at least two years, but judge with your nose. A rancid smell means expired lipstick. Storing it in the fridge will make it last longer.

If you know that you don’t use your lipstick or eye shadow enough before it goes bad, consider getting sample sizes. Many makeup counters will give you free samples of popular items for you to take home. These are also perfect for traveling.

As a rule of thumb, it’s best to keep your makeup to yourself. You don’t want the bacteria in your friend’s makeup any more than she wants yours.

If you like trying makeup at department store counters, make sure you see an employee cleaning the products first. You never know who’s been putting their fingers all over them.

— Anna Sowa, The Bulletin