A recent study found that some chemicals in sunscreen can be found in your blood after just a day of applying them liberally, but don’t freak out just yet — sunscreen is still considered safe to use, and you don’t even necessarily need to switch brands.
Is it bad for sunscreen to be absorbed through the skin?
Not necessarily. We’ve known for a long time that it can be absorbed, so this isn’t news. US FDA rules assume that some absorption can happen, but that if levels are above 0.5 ng/mL, extra safety studies should be done. The new study established that, yes, levels can get this high if you apply a ton of sunscreen.
How much sunscreen are we talking about?
People in the study used way more sunscreen than any of us do in real life. Researchers followed the directions that we’re all “supposed to” follow, applying 2mg of sunscreen per square centimetre of skin, and then applying that same amount again and again throughout the day. Realistically, most of us apply a quarter to half that amount at a time, and reapply less if at all.
Should I stop using chemical sunscreens?
You should definitely keep using sunscreen, since its benefits are pretty well established, and nothing about this study suggests that sunscreen is dangerous — just that it isn’t as well understood as we thought.
If you’re concerned, one option is to use titanium oxide or zinc oxide sunscreens, whose components are not absorbed into the skin. They have their own downsides, though: A thick layer of these sunscreens can give skin a white cast, and they may not protect as well against the entire UV spectrum.
Dr Anjali Mahto, dermatologist and author of The Skincare Bible, summed it up well when she wrote on Instagram: “Personally, I won’t be changing my pattern of use or product based on the findings above — whilst the study is interesting, it certainly does not reflect how I use my sunscreen in real life.”