Did You Know Sunscreen is Controversial?

Did You Know Sunscreen Sunscreen article by Amy Seufert illustration by Jake Johnson

Is Controversial? Sunscreens are regulated as over-the-counter drug products in the United States because of their active ingredients. In any pharmaceutical product, active ingredients are the substances that produce the effects of the drug, and in sunscreen, their effects are to either reflect or absorb ultraviolet (UV) radiation. As science has progressed, we have learned more about the absorption of sunscreen through the skin. In 2014, the U.S. Food and Drug Administration (FDA) implemented the Sunscreen Innovation Act, calling for further safety reviews, and in February of this year they updated the regulatory requirements for sunscreens. Former FDA Commissioner, Dr. Scott Gottlieb, stated that sunscreen requirements had not been updated for decades.

Scientists are currently interested in whether or not the active ingredients in sunscreen can be absorbed into the bloodstream, which may have an effect on hormones that travel in our blood. They also want to know if what is absorbed can impact our reproductive systems, or cause cancer. Recently, the FDA conducted a small study with 23 participants looking specifically at four active ingredients commonly found in sunscreen: avobenzone, oxybenzone, octocrylene, and ecamsule. For the study, researchers applied sunscreen to participants every two hours for seven days. Participants stayed in the clinic, away from UV light, for the duration of the study. Blood samples were collected at different time points throughout the week to determine concentrations of each active ingredient in plasma.

Their study, published in the Journal of the American Medical Association, found that all four ingredients were indeed absorbed into the participants’ bloodstreams, and the amounts were enough to warrant further investigation.

However, scientists also noted limitations in the study that need to be addressed in future research. For example, the participants remained indoors and were not exposed to UV light, heat, or humidity, all of which could have an effect on absorption. Also, each participant received the maximum dosage of sunscreen according to the suggested regimen of each product, and plasma concentrations of the active ingredients were not determined after a single application, but only after multiple applications. The brands of sunscreen used were not named.

This research is still in its early stages. Despite the findings, since we know UV radiation can cause skin cancer, the FDA still encourages people to use overthe-counter sunscreen products to protect against UV radiation, which we know can cause skin cancer. If you are concerned about which sunscreens to use this summer, past studies have confirmed that zinc oxide and titanium dioxide do not completely penetrate the skin, but still provide effective protection from the sun.