American sunscreen formulas hadn’t been updated in nearly 30 years—until early June, when the U.S. Food and Drug Administration (FDA) approved bemotrizinol (BEMT), a sunscreen ingredient widely used in Europe and Asia. Ahead of sunscreen containing BEMT hitting U.S. shelves later this summer, Alan Geller, a nurse, skin cancer prevention researcher, and senior lecturer on social and behavioral sciences at Harvard T.H. Chan School of Public Health, shares more about the ingredient and its potential to help prevent skin cancer, the country’s most common cancer diagnosis.
Q: What is BEMT, and how does it improve sunscreen?
A: BEMT is an important component of sunscreen products that have been sold in Europe and Asia since 1999. It’s a chemical sunscreen filter, which means that it blocks the sun’s ultraviolet (UV) rays from hitting the skin by absorbing them. (Mineral-based sunscreens reflect and scatter UV rays away from the skin.)
There are two notable types of UV rays: UVB is associated with burning of the skin and UVA is associated with aging of the skin. Sunscreens on the U.S. market provide good protection against UVB rays, but they’re less effective at protecting against UVA. Partially that’s because avobenzone, the ingredient that current chemical sunscreens rely on to block UVA rays, isn’t photostable, meaning it quickly breaks down when exposed to sunlight. This is a major shortcoming. Although UVB is a major cause of DNA damage leading to skin cancer, UVA also plays an important role in skin carcinogenesis and is now recognized as a significant contributor.
BEMT is a single ingredient that protects against both UVB and UVA rays, and it’s photostable. So we have good reason to believe that sunscreens containing this ingredient will provide greater protection than our current products—though it’s hard to quantify how much greater.
Another advantage to sunscreen containing BEMT is that it’s advertised to rub onto skin completely clear, unlike mineral sunscreens, which can leave a white cast. That cosmetic difference could hopefully make the application process less arduous and entice more people to use sunscreen.
Q: Why did it take so long for sunscreen containing BEMT to become available in the U.S.?
A: Some chemical sunscreen ingredients can be detected in the bloodstream even after normal use. Because of this, BEMT got caught up in the FDA regulatory system for decades. But the fact that the process was so drawn out shouldn’t turn anyone away from sunscreen containing BEMT. Many studies have concluded that BEMT has a very low absorption rate into the skin and bloodstream and overall is very safe to use.
Q: Once sunscreen containing BEMT hits the shelves, should people replace all of their current sunscreens? Should future purchases definitely be of the BEMT type?
A: We should be excited and encouraged by the products soon coming on the market—but no, I wouldn’t advise anyone to throw away their already purchased sunscreen. Especially because sunscreen containing BEMT might be quite expensive. A European company, DSM-Firmenich, has exclusive rights to sell sunscreen containing BEMT in the U.S. for 18 months. During this time, sunscreen containing BEMT may be marketed as a premium product rather than a mainstream one—and be priced accordingly. If someone wishes to switch their sunscreen to the one containing BEMT, and can afford to do so, they absolutely should. If not, keep using your existing sunscreen. Whatever the case may be, I suggest following best sunscreen practices, including:
- Apply sunscreen to everywhere on your body exposed to sunlight and make sure you use enough. To achieve the full protection a sunscreen can offer, it takes about one liquid ounce—or roughly two tablespoons, enough to fit into the palm of a cupped adult hand.
- Make sure your sunscreen is SPF 30 or greater.
- Keep an eye out for free sunscreen dispensers in your neighborhood—an essential public health initiative that more cities are adopting, one that can provide a good opportunity to apply or reapply on the go.
Learn more:
Skin cancer prevention expert on the importance of sunscreen (Harvard Chan School news)
