As anti-sunscreen misinformation spreads online, skin cancer advocates say beware

Globe and Mail

23-07-2025

Kelly Johnston's skin cancer journey began more than a decade ago, after a biopsy revealed that a red, scaly scab above her left eyebrow was basal cell carcinoma.
Since then, she's had other cancerous spots appear elsewhere on her body, including on her back. In 2022, Ms. Johnston received more serious news: She had melanoma, considered the most fatal form of skin cancer, on her left inner thigh.
Her melanoma was caught early and removed by her doctor, thanks to check-ins and screenings, which are, and will continue to be, part of her life as a skin cancer patient.
Ms. Johnston is part of a growing group of Canadians – including dermatologists and representatives for cancer organizations – who are speaking up about the dangers of ultraviolet radiation from sun exposure and artificial sources, as well as rising rates of skin cancer.
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This push for awareness is taking place at a time when physicians say misinformation about sunscreen is spreading online, including debunked theories positing that the products are toxic. Some posts on TikTok and Instagram claim that certain sunscreen ingredients, specifically oxybenzone and retinyl palmitate, are linked to cancer. Melanoma Canada says this is not supported by evidence.
The growth of online medical misinformation is considered a major public health problem because it undermines scientific research and contributes to negative health outcomes. In the case of sunscreen, dermatologists warn about dangerous and even fatal consequences linked to people turning away from its use. They say sunscreen offers critical protection from ultraviolet, or UV, exposure.
Ms. Johnston is concerned about what she's seeing play out on social media about sunscreen. This is coupled, she said, with how the platforms generate social pressures to look a certain way.
'Skin cancer, the risk of melanoma – this is serious stuff that is just not worth sitting in the sun or in a tanning bed for,' said Ms. Johnston, who is a 38-year-old content creator and model based in Owen Sound, Ont. 'You're naturally beautiful the way you are.'
The Canadian Cancer Society estimated that last year, 11,300 Canadians would be diagnosed with melanoma and 1,300 others would die because of it. Of those diagnosed, the society projected 6,500 would be men, and 4,800 would be women.
The World Health Organization says 85 per cent of melanomas that present in patients over the age of 30 are attributed to UV exposure. It also says tanning beds are a public health issue that account for about half a million new cancer diagnoses every year in the U.S., Europe and Australia.
Falyn Katz, the CEO of Melanoma Canada, said that the cancer can affect anyone, regardless of age, sex or race. Sunscreen and sun safety is important for everyone, she added.
'Why would we not take the opportunity to prevent a potentially deadly cancer?' she said.
Ms. Katz warns online misinformation about sunscreen is both worrying and dangerous. Some influencers, she said, are trying to teach people how to make their own sunscreen, without any of the medical background and knowledge required to do so.
She encouraged seeking information about sun protection from reputable sources. For instance, all sunscreens available for sale on shelves, including at pharmacies, must be evaluated and approved by Health Canada.
The Canadian Medical Association and other health organizations have also highlighted their concerns about the uptick in medical misinformation being widely shared on social media platforms.
Timothy Caulfield, who is the research director at the Health Law Institute, and a professor in the faculty of law and school of public health at the University of Alberta, studies this space.
He said what is playing out is nothing short of an 'anti-sunscreen movement.' This misinformation, he added, is creating real harm.
Prof. Caulfield pointed to the sway of online influencers, including American podcaster Joe Rogan, as a big factor. Mr. Rogan's show has explored questions on whether sunscreen can harm the brain.
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Meanwhile, there is robust evidence that sunscreen is effective and that most melanomas are caused by exposure to the sun, Prof. Caulfield said. At the same time, data shows younger people are less inclined to use sunscreen, which he sees as a direct result of the misinformation about it, as well as about the sun.
In May, a study led by McGill University found Canadians are spending more time in the sun, but using less sun protection. It also found young adults were much more likely to get sunburned and use tanning beds than older adults.
For Ms. Johnston, cancer has upended her pursuit of a golden glow. While she still seeks a bronzed look, it comes from self-tanner now, instead.
'Unsafe UV exposure, it catches up with you,' she said.
1. Look for apparel with UV protection: This can include clothing such as shorts, shirts, bathing suits and hats, from a variety of different brands.
2. Cover up as much skin as possible; consider long sleeves and a broad-brimmed hat.
3. Plan to do activities such as outdoor exercise or yardwork outside of peak UV hours, which are between 11 a.m. and 3 p.m.
4. Try to sit in the shade if you are outside.
5. Don't forget sunscreen. SPF 50 or above is recommended. Apply the product 20 minutes before swimming and reapply it every two hours or more.