As the first warm-weather weekends slowly trickle in, you dig in your cabinet for last summer's bottle of sunscreen to slather on any newly exposed skin. But wait. Does sunscreen expire? You bet it does. Here's how to tell if your SPF is off.
First, let's go over some basics of a solid sunscreen routine. Number one: You're wearing it year-round. Number two: You're applying it everywhere — even your eyelids. Number three: You're wearing a high SPF sunscreen for optimal protection. And finally, you're using sunscreen that's still fresh.
"Sunscreen absolutely expires and should never be used past its expiration date," Shari Marchbein, a board-certified dermatologist in New York City, tells Allure. "Like food, sunscreen can go bad and the ingredients can spoil, leading to a watery consistency," she explains. "They also become less effective, which means a significant increase in the potential for sunburns, sun damage, brown spots, and the risk for skin cancer development."
Why you shouldn't use expired sunscreen
There are two main issues with expired sunscreen. One, it won't protect you. "'Expired' means that the product should no longer be expected to achieve the SPF rating stated on the container," Perry Romanowski, an independent cosmetic chemist, tells Allure. That goes for both chemical and mineral sunscreens.
Chemical sunscreens that contain ingredients such as oxybenzone, avobenzone, and homosalate "can oxidize and become less effective," Romanowski explains. Mineral sunscreens — those with zinc oxide or titanium dioxide on the label — don't have that problem, but they do still degrade.
"This would include emulsion separation, graininess, preservative breakdown, color, and odor changes," Romanowski says. "So while the sunscreen ingredient still works, it may not spread properly on the skin to get the required film that gives the protection."
That leads us to the second problem with expired sunscreen. Even if the active SPF ingredient is still technically good, changes in the formula over time can make it both ineffective and problematic for skin. "Handling of the sunscreen container with dirty hands, or frequent opening and closing can expose the sunscreen to bacteria," Erin Gilbert, a board-certified dermatologist in New York City, tells Allure. As the bacteria grows in the tube, it can cause breakouts, she says.
When to replace your sunscreen
Most sunscreens are designed to last three years, says Gilbert. So, the first thing to do is check for an expiration date on the container (though not all brands have one, Gilbert warns).
But even if your sunscreen is only a summer old, there are other factors that might make the SPF spoil faster than the date stamped on the tube. "If you store your sunscreen in a warm place, like a car, by a pool, or in your purse, it will expire faster due to the heat," Gilbert says. "If it has been exposed to heat, you should replace it every few months, just to be sure it is still effective."
Regardless of the date, always test the consistency of your sunscreen before you use it. "Check for changes in texture, like clumping or pilling, or changes in smell," Gilbert says. "If your sunscreen starts to have a funny smell, it likely indicates that it has been contaminated with bacteria." This goes for both mineral and chemical sunscreens.
The bottom line? Experts recommend replacing your sunscreen every year. "If you use sunscreen generously and appropriately, a bottle shouldn't last you very long," says Marchbein.
Follow these steps to make sure your sunscreen routine is spot on:
1. Use enough sunscreen.
"One ounce — about a shot glass-size — is needed for the face and body," says Marchbein. If you're covered below the neck and just need to apply SPF to your face, use a teaspoon, she says. "The majority of cream sunscreens are three ounces, whereas sprays are often four ounces, so you are applying a third to a quarter of the bottle every two hours," she says.
2. Reapply religiously.
"Reapply your sunscreen every two hours," stresses Gilbert. "If you're wearing makeup, a powdered sunscreen can make that a less-daunting task. I like the Colorescience Sunforgettable Brush-On Sunscreen SPF 50. It allows you to layer added protection on top of your existing makeup."
3. Be proactive.
Adding antioxidants to your skin-care routine can help protect you from sun damage, says Gilbert. "Vitamin C is a potent antioxidant that can not only strengthen your skin but also reverse some of the pigmentation caused by UV exposure," she says. "I like Vichy LiftActiv Vitamin C Serum because it packs a punch at an affordable price point."
4. Have a backup method.
"Don't forget that sunscreen alone may not be enough to fully protect you from the sun," Gilbert says. "There are a ton of cute hats out there, as well as SPF workout gear, so no excuses, people!"
For more sun protection:
Now, learn all about the history of sunscreen:
Originally Appeared on Allure