How Long Makeup Lasts After You Open It

Most makeup in the United States is sold without an expiry date, because federal law doesn't require one on cosmetics. That doesn't mean it lasts forever. Once a product is opened, air, light, warmth and the bacteria on your fingers and brushes start working on it, and the preservatives that keep it safe gradually lose ground.

The clearest guide is usually printed on the packaging itself, if you know where to look.

The open-jar symbol

Look for a small drawing of an open pot with a number and the letter M beside it, such as 6M or 12M. This is the period-after-opening mark, and it tells you how many months the manufacturer expects the product to stay in good condition once it has been opened. It comes from European rules, which require it on cosmetics that keep for more than 30 months unopened. Products that keep for less time must show a "best before" date instead. Because so much makeup is sold internationally, you will find the symbol on plenty of products bought in the US as well.

The mark only works if you know when you opened something. A strip of masking tape with the month written on it, or a note on your phone, is enough.

Eyes

Mascara has the shortest life of anything in the bag, about three months. The wand goes into the tube and against your lashes every day, and the eye is easy to infect, which is why replacing it every three months is such common advice, including in guidance from the US Food and Drug Administration. If it dries out early, replace it rather than adding water or saliva, both of which introduce bacteria.

Liquid eyeliner lasts roughly three to six months for the same reason. Pencil liners last much longer, often a year or two, because sharpening takes off the used surface. Sharpen before each use if you can.

Cream eyeshadows are good for around six months to a year. Powder shadows can last up to two years, since dry powder gives bacteria little to live on.

Face

Liquid and cream foundation and concealer generally last six to twelve months. Pumps and squeeze tubes stay cleaner than open bottles you tip onto your fingers, so they often hold up toward the longer end.

Cream blush and highlighter are similar, six months to a year. Pressed and loose powders, including bronzer and setting powder, can last up to two years. A hard, shiny film on the surface is a sign of oil from brushes, and a powder that has turned patchy or crumbly has had its day.

Lips

Lipstick usually lasts one to two years. Lip gloss and liquid lipstick, which have a wand that goes back into the tube, are better replaced after about a year. Lip balm in a pot picks up more from your fingers than a stick does.

Nails

Nail polish doesn't really go off, but it thickens as the solvents evaporate, often within a year or two. A drop of nail polish thinner can revive it. Nail polish remover is a different product and tends to break the formula down instead.

When to throw something out early

Dates are a guide, not a guarantee. Toss a product sooner if the smell has changed or turned sour, if it has separated, gone lumpy or dried out, or if the colour looks different from when you bought it. If you have had an eye infection such as conjunctivitis, replace every eye product you used during that time, since they can carry the infection back.

Sunscreen and skincare

Sunscreen is regulated as an over-the-counter drug in the US, so it must carry an expiration date unless testing shows it stays stable for at least three years. Expired sunscreen may not protect as well as the label says. Check the date before summer, and replace bottles that have spent time in a hot car or beach bag.

Products with active ingredients such as vitamin C and retinol lose strength with exposure to light and air. A vitamin C serum that has turned dark orange or brown has oxidized. Products made without preservatives, or marketed as "natural", tend to have shorter lives than conventional ones, so their period-after-opening mark matters even more.

Making things last

Store makeup somewhere cool and dry, not on a steamy bathroom shelf. Don't pump a mascara wand, which pushes air into the tube. Wash brushes about once a week and sponges more often, since both pick up oil and bacteria with every use, and replace sponges once they start to tear or stain. Keep lids closed tightly. And don't share eye or lip products, even with close friends.