You reach into the back of your cabinet or rummage through your beach bag and find a bottle of sunscreen from last summer — or was it two summers ago?
But before you start applying it, there’s one thing you need to get in the habit of checking: the product’s expiration date. Yes, that date really does matter.
The biggest problem with using expired sunscreen is that it won’t provide the stated SPF, or sun protection factor, which can lead to sunburns and increase your risk for sun damage and skin cancer, dermatologist Dr. Joyce Park — founder of Skin Refinery and content creator @teawithmd — told HuffPost. So it’s better to be safe than sorry and toss any expired product.
“Sunscreen ingredients break down over time, so after the expiration date, we really don’t know how effective that sunscreen is at protecting your skin from UV rays,” she said. “This renders the sunscreen essentially useless.”
This is true of both chemical sunscreens and mineral ones (here’s an explainer on the differences between the two if you’re curious). The filters used in chemical sunscreens (like avobenzone and octinoxate) “tend to oxidise and lose efficacy over time,” dermatologist Dr. Shasa Hu, associate professor at the University of Miami Miller School of Medicine, told HuffPost.
While the filters in mineral sunscreens — such as zinc oxide or titanium dioxide — don’t have the same issue, other ingredients in these formulas still go bad, reducing the product’s ability to properly protect your skin.
For those with very sensitive skin, using expired sunscreen could lead to skin allergies or irritant dermatitis, Hu noted.
That said, in a pinch, using expired sunscreen is better than not using any at all.
“If you’re stuck in a situation where you have no other option other than using an expired bottle, then please go ahead and choose that over having no protection at all,” Hu said. “Most people will not react adversely to expired sunscreen. To compensate for lowered efficacy, apply more and reapply more frequently.”
How To Check If Sunscreen Is Expired
Most sunscreens have a shelf life of about three years. The expiration date can typically be found on the top edge of a tube, the bottom of a bottle or aerosol can, or somewhere on the label.
But not every sunscreen will have an expiration date printed on it. If there’s no date, it “should be considered expired three years after purchase,” per the Food and Drug Administration.
Consider writing the month and year of purchase in permanent marker on the sunscreen container when you buy it. That way, you don’t need to rely on your memory to know when it expires. This also comes in handy if the expiration date on the label gets smudged and hard to read over time.
Other signs a sunscreen has gone bad include a funky smell (which may be a sign of bacterial contamination), clumping, separation or “significant pilling when applied on the skin,” Hu said. If you notice any of these changes, it’s time to throw it away.
Opening the sunscreen should not speed up the expiration process, according to Consumer Reports testing. As long as it’s been stored at room temperature, “it will maintain its level of protection if it is still in that three-year window,” Susan Booth — the project leader for sunscreen testing at Consumer Reports — told the publication. “We have retested sunscreen samples from previous years’ testing after storing them in our lab and found no differences in performance.”
That said, even if the SPF remains intact, “handling of the sunscreen container with dirty hands, or frequent opening and closing can expose the sunscreen to bacteria,” dermatologist Erin Gilbert told Allure.
Sunscreen that’s been exposed to heat or sunlight “will likely lead to faster product degradation,” Hu said. So if it’s been sitting in your car, for example, you will probably need to toss it sooner.
If you’re headed outdoors, remember to keep sunscreen in the shade, inside a bag or wrapped in a towel. In your home, the best place to store sunscreen is an area that’s cool, dry and dark. So a humid bathroom probably isn’t the ideal spot — but your bedroom or a closet might be.