Sunscreen videos are all over TikTok — but the ones that go the most viral are the ones that are packed with misinformation, a study published Thursday in the journal Plos Digital Health found.

Researchers from the University of Alberta in Canada analyzed TikTok videos with the highest views across the five most popular sunscreen-related hashtags. Although the vast majority — 87% of the nearly 1,000 videos — promoted sunscreen use, the content with the highest levels of engagement were the ones that contained misinformation.

That misinformation ranged from “sunburns aren’t dangerous” to claims that sunscreen is toxic, said lead study author Alessandro Marcon, a University of Alberta researcher who studies how health information spreads in the media.

“There were specific mentions that sunscreen has a hormone-disrupting potential, it was cancer-causing, contained carcinogens, it could taint your breast milk or contain microplastics,” Marcon said.

Dr. Anthony Rossi, a dermatologist at Memorial Sloan Kettering Cancer Center in New York, said, “I have to spend a good amount of time in my consultation to talk about what actually is the truth: how sunscreen does actually help and how using sunscreen is not going to cause skin cancer or lead you to be vitamin D deficient.”

Rossi, who was not involved with the research, said sunscreen causing vitamin D deficiency is a narrative that has been rampant on social media. “There have been numerous studies that show even with regular daily use of sunscreen, you do not become vitamin D deficient,” he said.

According to the new study, a lot of sunscreen misinformation focuses on so-called chemical sunscreens, which use chemical filters to absorb harmful ultraviolet rays. (Mineral sunscreens, on the other hand, use mineral-based filters, either titanium dioxide or zinc oxide, to block the sun’s harmful rays.)

“There are currently no scientific indications that any ingredient widely used in ‘chemical’ sunscreens (e.g. oxybenzone) is harmful to one’s health,” the researchers wrote in the study.

Dr. Molly Hales, a dermatologist and researcher at the University of Chicago, said that “both chemical and mineral sunscreens’ ingredients are monitored and regulated by the FDA, which means they go through rigorous safety profiling, safety testing before they’re allowed to be sold, even though they are over-the-counter products.”

Marcon said that he understands the concern about microplastics, which are ubiquitous in daily life. However, he said, there is no indication that sunscreen exposes people at higher levels than other sources.

Thursday’s study is not the first indication that social media may be tainting people’s views on sunscreen and sun safety.

This year, one-third of Gen Z participants got a failing grade on the American Academy of Dermatology’s annual sun safety survey. The survey attributes this knowledge gap to social media: 36% of Gen Zers surveyed said they turn to influencers as their primary source of skincare information, even as 64% said they have encountered sunscreen misinformation online.

“I would say 95% of the misinformation we can attribute to social media,” said Dr. Marisa Garshick, a dermatologist at MDCS Dermatology in New York and an AAD fellow. “Whether it is directly because people are seeing people talk about problems with sunscreen or indirectly where it’s somebody’s favorite influencer who’s showing that they laid out in the sun for three hours and got tan lines.”

The ramifications are clear: Skin cancer is on the rise globally.

Garshick said she’s seeing more basal and squamous cell skin cancer diagnoses in her younger patients.

This is “just a sign of the fact that some of that sun damage that is affecting us really does start when we’re children,” she said. “I think that is what makes this social media situation so concerning, because this is where a lot of these teenagers are finding their information.”

Hales said that she often has new patients who don’t realize sunscreen is needed every day.

“I will say a fair number of new patients that are coming to see me for their first skin check are surprised to hear that we do recommend applying daily sunscreen, including when you’re not planning on maybe being out at a baseball game or on a hike or some other outdoor activity,” she said.

Garshick said she encourages people to find the sunscreen that works best for them, whether it is a chemical or mineral product. Expanded sunscreen options will be hitting the U.S. market soon, with the recent Food and Drug Administration clearance of the globally popular UV filter bemotrizinol.

“The best sunscreen is the one you will use,” she said.

Marcon, the study author, urged social media users to be cautious when it comes to getting health information from these platforms.

“When someone has a message that’s directly related to a product that they’re selling, you have to be extremely cautious about what that message is,” he said. “Audiences should be suspicious of content that makes them feel extreme emotions, especially fear, and health-related content that appears to be promoting either fringe ideas or specific political agendas, rather than a shared consensus of scientific findings.”