The anti-sunscreen movement is winning the algorithm, not the argument

Scroll long enough through TikTok or Instagram and you'll find them: confident, glowing people telling you to throw out your sunscreen. It's "toxic", they say. It's full of chemicals that leach into your blood. It blocks the vitamin D your body craves. Some go further and claim sunscreen — not the sun — is what's really driving skin cancer. The fix, conveniently, is often a "natural" alternative like beef tallow or coconut oil, sometimes with an affiliate link in the caption.

If you've felt the pull of these videos, you're not gullible. The claims are built around real fragments — a genuine FDA study here, a real product recall there — stretched far past what the science supports. But the conclusion they lead to is dangerous, and nowhere more so than in Australia and New Zealand, which carry the world's heaviest melanoma burden. This is worth getting right.

A small minority with an outsized megaphone

The first thing to understand is that anti-sunscreen content is not the majority view — it just performs like it is. Researchers at the University of Alberta analysed 971 of the most-viewed TikToks across the five biggest sunscreen hashtags, publishing their findings in PLOS Digital Health. The overwhelming majority — 86.8 per cent — promoted sunscreen use. Only about 6 per cent contained health-related critiques, such as claims that sunscreen causes harm or blocks the sun's benefits.

But that small minority punched far above its weight. The videos disparaging sunscreen attracted, on average, more likes, shares and comments than the accurate ones. Study author Alessandro Marcon summarised it plainly: TikTok is not flooded with sunscreen misinformation, but the videos dangerously claiming sunscreen is harmful or unnecessary draw comparatively high engagement. Outrage and contrarianism travel; sensible advice doesn't.

The audience is absorbing it. Coverage in SheKnows of the trend's effect on younger users noted that one in three Gen Z adults scored a D or F on the American Academy of Dermatology's sun-safety quiz, and 64 per cent said they'd encountered sun-related misinformation online.

In New Zealand, RNZ's Checkpoint found anti-sunscreen posts with close to half a million likes, made by influencers with followings to match — many with clear commercial motives, promoting alternative skincare products. Tauranga dermatologist Dr AJ Seine urged viewers to check what links and affiliations sit behind these posts, and noted he's seeing younger patients turning up with skin cancer diagnoses. That's the context for the alarm: Aotearoa has one of the world's highest melanoma death rates, and Australia has the highest skin cancer incidence anywhere. Two in three Australians will be diagnosed with skin cancer in their lifetime, and about 2,000 die from it every year, according to Cancer Council Australia.

Why the claims feel believable

It's worth being honest about why this movement resonates. Trust in institutions is low. The wellness world frames "natural" as safe and "chemical" as suspect, and that framing is intuitive even though it's wrong — arsenic is natural; water is a chemical. And the claims usually contain a seed of truth.

The 2021 recall of some aerosol sunscreens over benzene contamination was real — but as Columbia University's Herbert Irving Comprehensive Cancer Center explains, benzene is not a sunscreen ingredient. It was a manufacturing contaminant, the kind that has turned up in many consumer products, and the affected batches were pulled.

The correlation argument is seductive too. Otago University's Dr Bronwen McNoe told RNZ that influencers point out skin cancer rates and sunscreen use have both risen, then imply one caused the other. It's a textbook confusion of correlation with causation: sunscreen use rose because skin cancer rose, alongside better detection, an ageing population and the long tail of decades of unprotected tanning. As McNoe noted, what causes skin cancer is too much UV exposure — not sunscreen.

So the distrust is understandable. The claims themselves, though, collapse on inspection.

The four big claims, against the evidence

"Sunscreen causes cancer." There is no good evidence for this, and overwhelming evidence for the opposite. UV radiation is a proven Group 1 carcinogen: it damages the DNA in skin cells directly. Sunscreen, by contrast, demonstrably prevents that damage — a landmark Australian trial found people aged 18–40 who used sunscreen regularly from childhood cut their melanoma risk by 40 per cent compared with rare users. The Cancer Society of New Zealand's Rachael Neumann put it in one line: "Sunscreens are safe and they are regulated by strict safety standards." In Australia, sunscreens are regulated as therapeutic goods by the TGA — among the strictest regimes in the world.

"The chemicals end up in your bloodstream." Partly true, wholly misleading. FDA studies published in JAMA in 2019 and 2020 did find that several chemical UV filters can be absorbed into the blood above the agency's screening threshold under maximal-use conditions. But absorption is not harm. The FDA itself stated that the fact an ingredient is absorbed "does not mean that the ingredient is unsafe" — it simply triggers a request for more safety data from manufacturers. Both the FDA and the study authors were explicit that people should keep using sunscreen while that data is gathered. No study has shown these filters cause harm in humans at real-world exposures. And if the uncertainty still bothers you, mineral sunscreens using zinc oxide or titanium dioxide sit outside the question entirely — Cancer Council Australia notes there's no evidence the nanoparticle forms are harmful either.

"Sunscreen causes vitamin D deficiency." In theory, blocking UVB should reduce vitamin D synthesis. In practice, it doesn't meaningfully happen. Reviews in the British Journal of Dermatology examining field trials and observational studies found little evidence that real-world sunscreen use lowers vitamin D levels — partly because nobody applies sunscreen perfectly, and enough UVB gets through. The British Association of Dermatologists concluded sunscreen applied normally does not prevent vitamin D production in most healthy people. For the minority who are genuinely deficient, supplements are cheap, effective and don't come with a melanoma risk — a point Columbia's cancer centre makes explicitly.

"Natural alternatives work fine." They don't. The oft-cited claim that coconut oil offers SPF 7 traces back to a 2009 petri-dish study; later testing of coconut, olive, canola and other oils found SPF values close to 1. At best, coconut oil blocks roughly 20 per cent of UV, versus about 97 per cent for a properly applied SPF 30. Homemade zinc recipes fare no better, because home mixing can't evenly disperse the active ingredient. "Natural" sun protection is, functionally, sunburn with extra steps.

Where this leaves you

The evidence isn't ambiguous, and neither are we: wear sunscreen. Mineral or chemical — both work, both are safe under Australian regulation, and the best sunscreen is the one you'll actually apply generously and reapply. Cancer Council Australia's guidance remains SPF 30 or higher, broad spectrum, water resistant, used alongside shade, clothing, a hat and sunglasses whenever the UV index hits 3.

And if someone you love has gone down the anti-sunscreen rabbit hole, dermatologists suggest curiosity over combat — the distrust driving these beliefs is real, even though the claims aren't. The sun that gave this country its beach culture also gives it the world's worst skin cancer statistics. The influencers will have moved on to the next trend by winter. Melanoma won't.