Please don’t make your own sunscreen. If even the thought of doing that sounds crazy to you (and it should), then you’ll be as surprised as we were to hear about a rumor that home-brewed “sunscreens” (a major misnomer) actually work.
Just look at Pinterest and you’ll find recipes that call for ingredients like coconut oil, shea butter, zinc, and titanium dioxide. But even if you can find zinc and titanium dioxide (your guess is as good as ours where you’d do that), you 100 percent cannot make an effective sunscreen at home. For one thing, you have no clue what level of SPF you’re getting—if any.
“I have to use a high-pressure machine called a homogenizer to break up zinc and titanium dioxode particles and distribute them evenly through a formula,” says cosmetic chemist Ni’Kita Wilson. “There’s no way mixing with a spoon or a blender can come even close to do doing that, so you’re going to have entire areas of skin that are exposed to UV rays.” Also, coconut oil is a horrible base. “It doesn’t mix well with physical blockers, and it’s too thick to disperse them adequately, even with the kind of technology I have access to,” says Wilson.
And if you’re using coconut oil or rosehip oil—or any oil—you’re more likely to burn. “Homemade sunscreens do more harm than good, because oils can absorb light, making UV rays penetrate the skin more,” says Joshua Zeichner, a dermatologist in New York City. “That has the same effect as greasing up with baby lotion when you go to the beach. You’re increasing your risk for skin cancer.” And if you’re not already convinced, store-bought SPFs contain a variety of sunscreens because different ingredients protect against different wavelengths of UV rays. “You’re not getting adequate protection from just zinc and titanium dioxide alone,” says Zeichner. “There’s a reason even the most natural companies have to include chemicals in their suncreens,” adds Wilson. “It’s for your safety. There’s a lot of chemistry that goes into an SPF.” If all that sounds harsh, it’s only because we care.
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• 11 Sun Protection Tips From the Country’s Best Dermatologists
• Daily Beauty Reporter: Could Chocolate Replace Sunscreen?