You likely have a half-used bottle of sunscreen in the back of your medicine cabinet, and another one in the depths of a beach bag. If that’s the case, you might be wondering: Does sunscreen expire?
The answer is yes, according to the Food and Drug Administration (FDA) — but your bottle may last longer than you think.
The FDA requires all sunscreens to be marked with an expiration date, unless the product has been proven to last at least three years. So unless your sunscreen bottle is stamped with a specific expiration date, you can assume it’s good for three years past its purchase date, the FDA says.
However, you should still use common sense to determine whether your sunscreen is expired, says Dr. Joshua Zeichner, a dermatologist at Mount Sinai Hospital in New York City. “If a product does not look, smell or feel the way it did when you originally purchased it, you should discard it,” Zeichner says. Changes in consistency could signify that the product’s ingredients are no longer active, which “means that you have a false sense of protection against the sun and are more likely to develop a sunburn.”
Even unopened sunscreens can lose efficacy over time, Zeichner says, so it’s best to be cautious. “I generally recommend a new sunscreen every season,” he says. “You may not know how long a sunscreen sat on the shelf at the store before you purchased it, so it may be impossible to determine when that three-year mark is up.”
Another way to cut down on leftover sunscreen? Use more of it. “If you are using sunscreen properly, you are using about one ounce to cover the full body [each time], and you are reapplying sunscreen every two hours,” he says. “If you have the same bottle on Labor Day that you bought for Memorial Day, then you are likely not using enough.”
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Write to Jamie Ducharme at jamie.ducharme@time.com