Online misinformation about SPF is getting out of hand, so we asked the experts for the truth
Wearing sunscreen is important. It protects us from the harmful effects of UVA and UVB rays that wreak havoc on skin cells in terms of both health (cancer!) and beauty (wrinkles, age spots, etc.). Over the past few years, thanks to a lot of vital education about sun damage and the importance of SPF, sunscreen has skyrocketed in popularity, leading to more products, sunscreen influencers, and even SPF makeup trends.
But at the same time, a growing number of sunscreen skeptics have been spurred by recalls, controversy over chemical sunscreens, and a growing public distrust of doctors and scientists. Many are turning to natural oils and sun-based solutions. While many of their fears can be scientifically disproved, the one worry these skeptics share is not scientific at all: an unshakeable fear of governments and pharmaceutical companies.
As a result, misinformation is rampant on social media platforms like TikTok, a common problem on the site but particularly disastrous when it comes to this topic. In May, Cancer Research UK said it expects skin cancer rates to rise among people aged 25 to 49, with new cases increasing by 7% over the past decade. Even more alarming, researchers predict a record 20,800 cases this year in the UK alone.
Despite these warnings, skepticism persists, exacerbated by influencers like Nara Smith, whose “DIY sunscreen” how-to videos have been viewed 21 million times. To debunk the claims and theories swirling about SPF, we spoke to cosmetic scientists, skincare founders and naysayers for the facts.
Does benzene pollution make sunscreens unsafe?
Short answer: No.
Long answer: In May 2021, a lab found that 27% of 294 sunscreen products were contaminated with benzene, a natural gas used to make everything from plastics to detergents, but a carcinogen that’s restricted from use in sunscreens by the FDA due to its “unacceptable toxicity.” The products were quickly recalled and pulled from the market, but the incident has remained a legacy for skeptics ever since.
But cosmetic chemist Javon Ford says there’s no need to worry about the presence of benzene: “It’s a contamination issue, not a sunscreen issue.” If you’re still concerned, there’s a simple solution to avoid possible benzene contamination in the future. “Benzene typically forms in aerosol products, and those aren’t the best for adequate coverage,” Ford continues. “If you’re concerned, avoid aerosol sunscreens.”
Do chemical sunscreens contain harmful ingredients?
Short answer: No.
Long answer: Ingredients used in chemical sunscreens like oxybenzone, octocrylene, and avobenzone provide a thinner consistency and a white, cast-free finish, but safety issues are frequent concerns. This is likely due to how sunscreens block sunlight: The active ingredients are absorbed by the skin, absorbing UV rays and converting them into heat, which is then released from the body.
Cosmetic chemist Dr. Michelle Wong said FDA studies in 2019 and 2020 that found “higher levels of sunscreen ingredients in the blood than would automatically be assumed to be safe” could also be a cause for concern. But she also noted that sunscreens are medicines, and therefore “much more” studied and scrutinized than other products. “So even though there’s not much overall, there are more red flags that pop up.”
In 2022, the FDA issued an update saying these ingredients are indeed safe. “Regulatory agencies such as the FDA and the European Commission have reviewed this data,” explains cosmetic chemist and postdoctoral researcher Ava Perkins. “They continue to determine that, at the levels currently used, chemical and mineral UV filters are safe.” That being said, if you’re worried, you can always opt for alternatives. “Even if you’re against chemical sunscreens, there are plenty of mineral sunscreen brands that use natural ingredients that may fit your philosophy,” suggests Ford.
Does sunscreen disrupt hormones?
Short answer: No, but it’s still being determined.
Long answer: Another commonly raised concern is the potential for endocrine disruption caused by sunscreen. But Perkins argues that this is a delicate issue. “Research has shown that UV filters can be absorbed through the skin and can have weak estrogenic activity – that is, they can mimic estrogen in the body. However, the concentrations required to cause significant endocrine disruption are much higher than those typically seen with sunscreen use.”
Dr. Wong echoes Dr. Perkins’ comments: “This is an active area of research, but the current evidence does not show a clear link to endocrine disruption in humans,” she asserts. “I don’t think any scientist would say it’s impossible, but the evidence actually shows that it’s not.”
Can you make sunscreen using natural oils?
Short answer: Don’t worry about it.
Long answer: Many people have decided to replace their sunscreen with natural ingredients like tallow, coconut oil, carrot seed oil, raspberry oil, and even butter. If you watch these videos on TikTok, you’ll see that many ingredients are assigned SPF levels. Creators cite a 2010 study for most oils’ SPF, while some cite a 2024 study on carrot seed oil’s SPF level.
But what they don’t mention (or understand) is that studying oils in vitro, which means testing in a test tube, means they haven’t been tested on skin. “You read the scientific literature, you have to understand the methodology used and whether the conclusions make sense for human use,” Perkins explains. Meanwhile, a 2024 study is actually testing the oils when added to a Neutrogena sunscreen with SPF 30. “If the natural oil really has an SPF value of 30 or 40, that’s what we use,” Ford jokes.
If you want to make your own, the theory is that mixing these oils based on their SPF values will create an effective at-home sunscreen. “I’m currently doing a PhD research project on this, but no, it’s not that,” Perkins explains. “Ingredients interact with each other in more complex ways than simple addition. When I mixed a ‘natural’ SPF 8 and a 6 in a test tube, I got an SPF 8, not 14.”
Can zinc oxide be used to make sunscreen?
Short answer: No.
Long answer: Nara Smith used zinc oxide for her DIY sunscreen in a viral TikTok. Zinc oxide sits on top of the skin, leaving a white mark and proven to scatter, reflect, and absorb UVA and UVB rays. But it’s not as simple as it seems. “There’s cosmetic grade zinc oxide and then the kind you get for paint,” Ford warns. “The paint version has a higher lead content.”
Then there’s the issue of mixing. Not only does it require industrial homogenizers to mix properly, but it takes a very long time for cosmetic chemists to get it right. “The problem with zinc oxide is that its sunscreen effectiveness isn’t just determined by the amount, but also by how it’s dispersed,” explains Dr Wong. “Big round globs give you different coverage than small, uniformly dispersed particles. Also, uncoated, non-nano zinc oxide has a tendency to cake. That makes sunscreen one of the most difficult products to formulate.”
@charlotteparler #stitch with @Nara Smith Zinc is a great ingredient but this is dangerous. Buy sunscreen and use this as a moisturizer. Please avoid this kind of content and homemade over the counter remedies but the comments are worrying #sunscreen #SPF #homemade ♬ Just Give Me One More Day – Alej
Is it possible to make it resistant to the sun?
Short answer: No!
Long answer: Sarah Parker, a Colorado-based holistic health practitioner, has become critical of sunscreen after her experience with chronic vitamin D deficiency. She now uses a small amount of zinc sunscreen and focuses on diet, protective clothing and sun-tolerance. “Since spring, I’ve been exposing my skin to small amounts of sunlight for 15 to 20 minutes each day. This helps protect the skin from tanning and builds up melanin.”
But skincare and skin health experts don’t accept this as a legitimate practice. “This is the ‘base tan’ theory that I believed in as a kid, but it’s false,” says Charlotte Palermino, owner of Dieux. “It’s like saying if you drink a lot of alcohol, you’ll develop a tolerance. It’s true, but it’s not good for you.” Dr Wong adds that while the science that tanning provides protection is technically correct, it can still do harm. “Tan contains melanin, which acts as a natural sunscreen, but the amount is not that high, around SPF 1 to 4. You’re damaging your skin to gain a tolerance.”
Are these companies only interested in increasing profits?
Short answer: No.
Long answer: It’s not surprising that people are skeptical of the pharmaceutical industry. The Sacklers, Martin Shkreli, the Holmesburg Prison Experiment, and the diet pill industry, to name just a few, have all worked hard to give the pharmaceutical industry a bad name. As a result, more people than ever are questioning the safety of sunscreen, who makes it, and how we should look after our health. But Ford argues that while people have a right to be skeptical, they’re looking at it in the wrong direction.
“People don’t understand that it’s not big pharma companies that make sunscreen. It’s regulated as a drug, but it’s not made by a pharmaceutical company,” he says. “These are usually cosmetic companies, companies that you trust with your skincare or soaps. You trust other brands, so why wouldn’t you trust sunscreen?”
