SPF 100 Sunscreen Is Everywhere—But Do You Really Need It?
Photo by: Mikhail Nilov on Pexels.
On my recent commute home, an ad for a new SPF 100 sunscreen caught my eye.
SPF 100? What happened to SPF 30—or even 50? Was this the ultimate evolution of sun protection or just marketing gone rogue?
To find out, I spoke with Dr. Geeta Yadav, a board-certified dermatologist and founder of FACET Dermatology in Toronto.
What’s the difference between SPF 50 and SPF 100?
At first glance, SPF 100 doesn't sound all that impressive: SPF 50 filters about 98 percent of UVB rays, while SPF 100 filters 99 percent. One extra percent hardly seems worth the hype. But according to Yadav, that's where things get interesting.
“The real-world difference is bigger than the one percent suggests,” she says.
An American clinical trial from 2018 found that after a long day in the sun, roughly 55 percent of participants experienced more sunburn on skin protected with SPF 50 compared to only 5 percent pf participants who wore SPF 100.
That’s because, Yadav says, most of us aren't using sunscreen correctly. “SPF is tested at a thick, standardized layer that almost no one replicates in real life,” she says.
In reality, most people only apply a quarter to half the recommended amount—not to mention many forget to reapply throughout the day. That means your SPF 100 may end up performing more like an SPF 50 or less.
But that doesn't mean everyone needs to rush out and buy the highest number on the shelf.
Do you really need to wear SPF 100 every day?
For everyday wear, Yadav still recommends a broad-spectrum SPF 30 or higher regardless of skin tone.
SPF 100, though, really earns its star status during prolonged sun exposure: think long beach days in the blazing sun or hitting the slopes on a ski trip. Research from another 2018 study found that SPF 100 sunscreen reduces UV-related skin and DNA damage more effectively than lower-SPF products.
It also offers additional protection for those with a history of skin cancer, a compromised immune system or those taking medications with increase sun sensitivity.
But while SPF 100 offers a greater safety net, it shouldn’t be mistaken for a magic force field. “Sunscreen works best as one layer of protection alongside shade, a hat and protective clothing, not as a permission to expose the skin to unlimited sun,” says Yadav.
So no, you probably don't need SPF 100 for your office commute. But if you are prone to missing a reapplication, that extra buffer may be helping you more than you think.
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Sarah Bauly is the assistant editor at Chatelaine. She’s driven by a passion for empowering women and creating meaningful change through storytelling. Outside of writing, she can often be found getting lost in her favourite ’80s hits, lingering in bookshops or exploring the city in search of her next go-to coffee spot.
