Anti-sunscreen movement gains popularity on social media

In a TikTok video, a young man appears poolside. He writes, "I refuse to believe the sun is bad," along with the hashtag #nosunscreen, or "no sunscreen." Scrolling a little further, the algorithm displays another post, this time from a Brazilian man, who says he hasn't used sunscreen in five years, even though he sunbathes every day. He emphasizes that he uses coconut oil for hydration and claims his vitamin D levels are excellent. Throughout the post, the young man also states that he's not against sunscreen, but rather against chemical sunscreens.

And these are just examples among thousands of similar pieces of content from around the world, with "warnings" about the disadvantages of using sunscreens. According to the movement's supporters, these products are toxic and prevent vitamin synthesis, leading to long-term hormonal changes.

Furthermore, recommendations for daily use are considered propaganda to benefit the industry's profits. Other social media users share content claiming that sun exposure without sunscreen boosts immunity. Instead, they encourage the use of shea butter and annatto, among other natural products.

The issue has concerned doctors and specialists worldwide. The Skin Cancer Foundation, an organization that works on the prevention, detection, and treatment of skin cancer in the United States, published a statement reaffirming the safety of sunscreen. The American Association of Dermatology (AAD) has also spoken out in favor, as has the Brazilian Society of Dermatology (SBD).

To understand the truth and myth in this story, IstoÉ spoke with dermatologist Elimar Gomes, a member of the Brazilian Society of Dermatology (SBD) and Coordinator of the Dermatology Group at the BP Oncology Center – A Beneficência Portuguesa (SP), and dermatologist Claudia Marçal, a member of the SBD, the American Academy of Dermatology (AAD), and the Brazilian Society of Dermatological Surgery (SBCD). Read on.

Unprotected sun exposure can cause cancer

" Unprotected sun exposure is the main environmental risk factor for skin cancer," notes dermatologist Elimar Gomes. "Ultraviolet radiation (UVA and UVB) damages the DNA of skin cells and generates specific mutations, called UV signatures—a typical pattern of genetic alterations caused by solar radiation," he adds. He further explains that this signature is so characteristic that it functions as a "fingerprint" of radiation in tumors, frequently identified in skin cancer biopsies.

Several studies show that regular and correct use of sunscreen reduces the risk of skin cancer, from melanoma, the most aggressive type, to the most common type, carcinoma. An Australian study, published in the Journal of Clinical Oncology , for example, followed adults for over a decade and demonstrated that daily sunscreen use reduced the incidence of melanoma by 40%.

In addition to cancer, it's been proven that excessive sun exposure also aggravates several dermatological diseases, such as melasma, lupus, rosacea, porphyria, and other light-sensitive conditions. Not to mention that sunscreen also plays a fundamental role in protecting against premature skin aging.

The sun also brings health benefits

It's safe to say, however, that the videos get one thing right, albeit in a distorted way: sun exposure can indeed be beneficial for your health when done responsibly. "The sun can bring benefits—such as well-being, circadian rhythm regulation, and vitamin D synthesis—as long as exposure is moderate, planned, and compatible with individual tolerance," advises the BP dermatologist.

Therefore, the current recommendation is so-called broad photoprotection, which includes sunscreen and goes beyond that. The idea isn't to avoid the sun, but to take advantage of its benefits and minimize the risks. "Sunscreen is an important tool, but not the only one," summarizes the doctor. Experts' tips for safely enjoying the sun's benefits, in addition to using sunscreen, include:

• Avoid peak times, from 10am to 4pm;

• Choose suitable clothing, with light fabrics or even with UV protection;

• Wear caps and hats, and glasses with UV protection;

• Alternate sun exposure with periods in the shade.

Vitamin D replacement, only with a doctor's prescription

Another "concern" raised by the anti-sunscreen movement is the barrier the product forms on the skin, which would prevent the absorption of vitamin D. But that's not quite the case. Although ultraviolet radiation is necessary for vitamin D production, important studies, such as a literature review by a group of physicians from various specialties and different countries, published in the British Journal of Dermatology , have already shown that vitamin D is not significantly compromised by sunscreen, even with regular use.

" Both the Brazilian Society of Dermatology and other medical organizations recommend that vitamin D deficiency be treated with adequate supplementation, under medical supervision—and not with unprotected sun exposure, which offers greater risks than benefits. It is entirely possible to maintain healthy vitamin D levels without sacrificing photoprotection," says the BP dermatologist.

Modern sunscreens are non-toxic

Some arguments against sunscreen use revolve around potential toxicity. In fact, some older formulations contained active ingredients such as oxybenzone, whose blood concentrations after one day of use exceed a safe limit for the skin. "This information does not, in itself, mean that oxybenzone is toxic or causes disease in humans," the doctor explains. Rather, he says that further studies on its long-term effects are needed.

In any case, the presence of filters that have fallen into disuse, such as oxybenzone, has been questioned by science. But the reason is the potential these substances have to cause environmental impacts, especially in marine ecosystems. "Unfortunately, Brazil still has legislation that allows the use of some chemical sunscreens, which are already banned in the United States and the European Union," says dermatologist Claudia Marçal. Therefore, it's recommended to pay attention to the labels when buying domestic sunscreens, avoiding chemical components such as oxybenzone, benzophenone, and homosalate, even though they are rare today.

The most modern sunscreens are also popular in multifunctional versions. "Products that offer photoprotection combined with moisturizers, such as hyaluronic acid, collagen signaling peptides, or pigmentation inhibitors, as well as antioxidants and vitamins, such as vitamin E and vitamin C, are interesting," says dermatologist Claudia, emphasizing that photoprotection should be a priority in your skincare routine.

Natural oils offer little protection from the sun

Technological development in sunscreens has advanced significantly in recent years. Today, we have filters that offer better UVA/UVB photoprotection and lower transcutaneous absorption, which reduces the risk of systemic effects, according to experts consulted by IstoÉ.

Therefore, replacing sunscreen with natural substances like coconut oil, olive oil, shea butter, or annatto, besides lacking scientific support, can be dangerous. "These ingredients have low sun protection factors, unable to effectively block ultraviolet radiation, the main cause of burns, premature aging, blemishes, and skin cancer," says Gomes. This idea, as the expert points out, stems from the information that traditional populations did not develop skin cancer due to their use of olive oil or coconut oil. This is a simplification that ignores fundamental factors, such as the characteristics of these people's skin.

In addition to the current degradation of the ozone layer, a protective shield against ultraviolet rays, the comparison is not appropriate because ancient peoples' behaviors differed from those in today's urban context. "Life expectancy was considerably lower in these populations, which reduced the likelihood of developing diseases related to accumulated sun damage, such as skin cancer, which often appears after age 60," he concludes.