Does Sunscreen Really Absorb Into Your Bloodstream?
Apparently, it does, according to new research—but does that mean sunscreen is unsafe?
It's almost summer, folks. The days are getting longer, the sun is getting stronger, and you're lathering up your body with all the sunscreen. But how much do you really know about all of those creams and sprays you apply to your skin? For instance, did you know sunscreen can absorb into your bloodstream? Apparently it's a thing, according to a new pilot study from the FDA. (Related: The FDA Is Aiming to Make Some Big Changes to Your Sunscreen)
Researchers from the Center for Drug Evaluation Research (CDER) at the FDA recruited 24 volunteers for a random clinical trial study to find out whether the active ingredients (avobenzone, oxybenzone, octocrylene, and ecamsule) in four commercial sunscreens absorb into the bloodstream, according to the study published in JAMA earlier this week.
Volunteers applied one of four different types of sunscreen—a cream, lotion, or one of two sprays—over 75 percent of their body, four times daily (i.e. the maximum recommended daily dose, the study explained). Participants also submitted 30 blood samples over the course of the seven-day trial period. In the end, researchers found that all four sunscreen ingredients had absorbed into the volunteers' bloodstreams. (Related: Is This Controversial Ingredient In Your Sunscreen Doing More Harm Than Good?)
Though the idea of chemicals absorbing into your bloodstream might sound unnerving, it isn't necessarily unsafe, according to the FDA's press release. It just means that further research needs to be done in order to definitively say whether the ingredients are safe for regular application.
BTW, the FDA isn't the only organization keeping tabs on the safety of sunscreen chemicals. In 2014, researchers in Australia found that while certain sunscreen ingredients can absorb into the skin, white blood cells called macrophages usually discard and break down those ingredients before they reach the bloodstream. (Related: The Best Face and Body Sunscreens for 2019)
However, all of this research is preliminary, not to mention both studies have limitations. They were both conducted in laboratory settings, meaning none of the participants were exposed to direct, natural sunlight at any point in either study. Moreover, the FDA study's sample size was pretty small, so "further studies [are needed] to understand the clinical significance of this," Dr. David Strauss, director of the division of applied regulatory science at CDER and one of the study’s co-authors, told Time. Similarly, the results of the 2014 Australian study were considered by most experts to be "premature," Louise Sales, of the environmental group Friends of the Earth, told the Australian Broadcasting Corporation.
What we do know is this: Sunscreen works in one of two ways. Chemical sunscreens are absorbed into the skin; they absorb UV rays, convert those rays into heat, and release them from the body, says David E. Bank, M.D., a board-certified dermatologist based in New York. Physical sunscreens, on the other hand—whose main ingredients are zinc oxide and titanium dioxide—sit on top of the skin and reflect UV rays, Bank explains.
Aavobenzone, oxybenzone, octocrylene, and ecamsule—the chemicals the FDA tested for traces in the bloodstream, "are ingredients used in sunscreen to block UV rays to protect the skin from DNA damage," Bank tells Shape. And as far as experts know, these ingredients are not dangerous to humans, he says. (Related: Sunscreens for Working Out That Don't Suck—or Streak or Leave You Greasy)
"The risk of not using sunscreen outweighs the benefits of not wearing sunscreen," Bank explains. "For those concerned about these chemicals, physical sunscreen containing zinc oxide, like the Jack Black Sun Guard SPF 45, is a great alternative to protect against both UVA and UVB rays. In addition to sunscreen, people should wear protective clothing that covers the skin and seek shade during hours of peak sunlight."
Bottom line: Some sunscreen ingredients might absorb into your bloodstream, but you should still continue to lather up regardless, at least until further research has been done on the subject.