Somewhere in your beach bag is a bottle of SPF 100. You bought it because 100 sounded like triple the protection of 30. That is how numbers work everywhere else in life. Sunscreen is the exception.
The Journal ran the arithmetic on Monday, and the gap is tiny. At SPF 30, a sunscreen already blocks 97% of the UVB rays that burn you. SPF 100 blocks 99%. SPF 50 sits between them at 98%.
Two percentage points. Not triple. And no bottle ever gets you to 100% — that number does not exist in sunscreen.
The label fight
Scientists are still arguing about the big numbers, and it would be dishonest to pretend otherwise. Some studies suggest SPF 100 gives a real edge over SPF 50. Other health advocates argue the opposite. A giant number, they say, creates a false sense of security. People who feel bulletproof forget to reapply.
Regulators have chewed on this for fifteen years. The FDA has toyed with capping advertised SPF values since 2011, arguing that numbers stretching toward 100 mislead people. The cap was first proposed at 50, then raised to 60. The agency never made a final decision.
So the choice stays with you and the bottle. The dermatologists in the story are refreshingly relaxed about which one you grab. “The best sunscreen is the one that you’re actually going to use,” said Dr. Helen He, a Mount Sinai dermatologist.
The new ingredient
There is real news here too. The FDA approved bemotrizinol — a sunscreen ingredient known as BEMT for short. It is the first new one the agency has approved since the late 1990s. Europe and Asia have used it for decades. Dermatologists call the approval long overdue, which is the polite version of that sentence.
Now read the date carefully. Aug. 9 is the day companies can start putting the ingredient into their products. It is not the day it lands at your drugstore. “Innovation on some of these products can take a year,” said Bank of America analyst Anna Lizzul.
Two familiar names have said something, and neither said much. Kenvue, Neutrogena’s parent company, confirmed it plans to add bemotrizinol but gave no date. CVS Health said it is having conversations with its store-brand sunscreen supplier. That is a maybe and a chat. Do not go shelf-hunting on Aug. 10.
What actually works
A quick word about the SPF hiding in your makeup. SPF now shows up in moisturizers, foundations, concealers, powders and lip balms. At stores like Ulta and Sephora, twice as many SPF tinted moisturizers and foundations launched in the first five months of this year as a year earlier, according to data firm Circana.
Extra SPF is helpful, but it is not one-and-done protection. Dr. He says you would need several more layers of foundation than normal to hit the SPF printed on the box. Heading outside? Wear actual sunscreen underneath the makeup.
The bottom line from the paper is boring, which is usually a good sign. Use SPF 30 or higher every day. Reapply every two hours. UV exposure is a known carcinogen — a cancer-causing agent — and it is far more dangerous than any specific sunscreen choice.
One more thing for a California July. In extreme heat, sunburns are extra dangerous because they limit the body’s ability to cool itself. The number on the bottle was never the thing protecting you. Using it on schedule was.