Don’t Use That Bottle Of Sunscreen Without Checking This First

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 oxidize 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 formulasstill 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