Sunscreen Is Definitely Entering Your Blood Stream but Don't Stop Using It

New FDA research shows sunscreens active ingredients are present in our blood.
Jessica Miley

The America Food and Drug Administration (FDA) has found that some sunscreens active ingredients can enter our bloodstream, but they aren’t sure of the health effects. They also urge people to continue to use the product.


Despite the widespread use of sunscreen to prevent sunburn and resulting cancer, there has been very little scientific research into what the long-term health effects of using the product actually are.

Some studies have shown that the active ingredients in some brands of sunscreen have serious detrimental effects on sea life, but what it does to the human body remains mainly a mystery.

FDA knowledge-based mainly on animal trials

The FDA grandfathered approval in many of the active ingredients of sunscreen before the modern era of drug evaluation, as part of the Generally Recognized as Safe and Effective (GRASE) list. This approval was based mainly on animal exposure studies. Recently though the FDA has clamped down on sunscreen and has proposed a new rule that would require additional safety testing in humans for a majority of active ingredients used in sunscreens.

Under this new mandate, only two of the 16 common active ingredients - zinc oxide and titanium dioxide - in sunscreen would still be considered GRASE. One area that the FDA is keen to know more about is how much an active ingredient of sunscreen is absorbed into the human bloodstream.

New study finds active ingredients in high levels

fresh paper describes the result of a recent randomized trial to begin work in this area. The study had 24 people who were asked to apply one of four sunscreen products chosen at random (two sprays, a lotion, and a cream) to 75 percent of their body, four times a day, for four days.

This intense application schedule is close to what someone would use if they were working outside and following the manufacturer's reapplication instructions.

The researchers then tested the volunteer's blood for four active ingredients: avobenzone, oxybenzone, octocrylene, and ecamsule.

Keep using sunscreen

The research team found that all four active ingredients were well above the threshold previously established by the FDA for how much of an active ingredient in sunscreen could safely end up in a person’s blood.

Levels above this would require additional toxicology testing including how carcinogenic or hormone-disrupting a particular chemical could be.

Despite the initial worrying results, the studies authors are not saying that sunscreen is dangerous - not at all.

The study itself is full of weaknesses including the fact that the volunteers did not actually go outside during the experiment and its highly likely that exposure to, humidity, the sun's UV and other environmental factors would have altered the level of chemicals.

The authors are fully aware there needs to be a whole lot more research before they start telling people to stop applying the life-saving lotion: “Systemic absorption of sunscreen active ingredients supports the need for further studies to determine the clinical significance of these findings,” the scientists declare.

While future studies will likely piggyback off this initial work, the road ahead to understanding the health effects of sunscreen research are just beginning.

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