Are chemical sunscreens safe? Dermatologists reveal what the science really says

With so many claims flying around TikTok, it's no wonder people are confused — and concerned — about the safety of chemical sunscreens.

"I just had a patient who is on his sixth melanoma, and he asked about chemical sunscreens," Dr. Abigail Waldman, clinical director of the Mohs and Dermatologic Surgery Center and Brigham and Women’s Hospital and assistant professor at Harvard Medical School, tells TODAY.com.

Similarly, Dr. Helen He, practicing dermatologist and assistant professor of dermatology at the Icahn School of Medicine at Mount Sinai, tells TODAY.com that she's seen a lot of headlines about the topic recently.

"And in my clinic, I will occasionally get questions from patients about (whether) certain sunscreens are carcinogenic or if they have effects on hormone levels," she says.

Ultimately, the experts agree: "The best sunscreen is the one that you are going to use consistently," Waldman says, as long as it's at least 30 SPF and comes with broad spectrum protection.

And, despite the scary headlines and chatter on social media, many people can safely choose a chemical sunscreen.

What is chemical sunscreen?

Sunscreen active ingredients fall into two broad categories: chemical and mineral (also called physical sunscreens).

If you look at the ingredients label on a sunscreen in the U.S., you'll see a box with the active ingredients listed out, Waldman says. Chemical sunscreens are identifiable by their active ingredients, such as oxybenzone, avobenzone and octinoxate.

These ingredients protect against UV rays by absorbing the light and converting it to a non-harmful state, Waldman explains.

When it comes to mineral sunscreen ingredients, "there's really just two types that are available: zinc oxide and titanium dioxide," He explains. These ingredients also absorb some UV rays and convert them to heat, but they also block and reflect some of that light, Waldman says.

In some products, you might also see a combination of chemical and mineral sunscreen active ingredients listed on the label.

Are chemical sunscreens safe?

Absorption

Much of the concern around chemical sunscreens today stems from a Food and Drug Administration study published in JAMA in 2019.

The researchers in that study investigated whether or not a few common chemical sunscreen ingredients — avobenzone, oxybenzone, octocrylene and ecamsule — could be absorbed into the bloodstream. After a few days of applying the sunscreen, they were able to detect those ingredients in the participants' blood samples.

Of course, that's a concerning finding. But the experts emphasize caution in interpreting these results.

First off, the "participants were applying sunscreen under what we call maximum use conditions," He explains. In this study, that meant 75% of each participant's body was covered with sunscreen four times a day for four days.

"It's a lot of sunscreen in a very large body surface area that I think far exceeds what the typical person usually applies," He says. But it was under those conditions that the researchers "saw trace amounts of systemic absorption," she adds.

However, the FDA is clear that even if a small amount of chemical sunscreen ingredients are absorbed, that doesn't automatically equate to health risks. The findings "do not mean that the FDA has concluded that any of the ingredients tested are unsafe for use in sunscreens," the administration said in a statement.

And the experts TODAY.com spoke to agree: If you enjoy using chemical sunscreens, you don't need to give them up.

"While recent studies have shown that some chemical sunscreen ingredients can be absorbed into the body through the skin, the data does not show that there are any effects on a person’s health," Dr. Seemal R. Desai, president of the American Academy of Dermatology, tells TODAY.com in a statement. "Those with concerns about chemical sunscreen ingredients can opt for a physical sunscreen."

Cancer

"There's no data showing that (chemical sunscreens are) associated with increased risk of cancer at all, of any type of cancer," Waldman says.

On the flip side, regularly using broad-spectrum sunscreen with at least 30 SPF can significantly reduce your risk for melanoma, she says, as well as squamous cell carcinoma, a non-melanoma skin cancer. "The overall theme is: Sunscreen does protect against skin cancer, whether it's a chemical sunscreen or whether it is a mineral sunscreen," she explains.

The caveat, Waldman adds, is that independent lab testing revealed the presence of the carcinogen benzene in some sunscreen products, particularly spray sunscreens.

"That is likely due to the propellants that they use to make the spray," she explains, and the issue is not unique to sunscreens. The chemical may be found in higher amounts in dry shampoos and body sprays, for instance, Waldman says.

Products from major brands like Coppertone, Banana Boat and Johnson & Johnson were recalled due to the findings.

Endocrine disruptors

"There are a lot of ingredients in cosmetics, hair care and sunscreen that can act as endocrine mimickers in a lab, meaning they kind of act like a hormone," Waldman explains.

But He stresses that, when it comes to chemical sunscreen ingredients, the potential link largely comes from animal studies that likely don't translate to humans. For instance, in many studies, researchers are feeding large amounts of these ingredients to mice, He explains, which is "not really comparable to a human situation."

Although we don't entirely know what the effects in humans may be, Waldman tells TODAY.com she may discuss the topic with patients who have hormone-sensitive conditions. Specifically, that would include people with hormone-sensitive cancers (which includes certain types of breast cancer and ovarian cancer) as well as those who are pregnant or trying to conceive, she says.

"There's not great data in those groups," Waldman says, "but using common sense, if you have a hormone-dependent state like pregnancy or infertility, (it makes sense) to avoid chemical sunscreens and choose a mineral sunscreen instead just to be on the safe side."

In the world of obstetrics, experts may be a little more "aware" of the issue, Waldman says. And the American College of Obstetrics and Gynecologists does recommend doctors tell their patients that avoiding certain ingredients — including oxybenzone — may lower their exposure to hormone-disrupting chemicals. But those chemicals are in many products, so just avoiding them in sunscreen is "probably not making a big difference," Waldman adds.

Similarly, He discusses the data with pregnant patients who are curious, but puts it into context. She talks with patients about chemical sunscreen the same way she does other ingredients or medications that fall into the "middle category," where there haven't been any conclusive studies in pregnant patients either way.

These conversations often come down to an individual patient's priorities, the experts agree, and different dermatologists may give you different guidance.

Who should avoid chemical sunscreens?

If you're concerned about chemical sunscreens for any reason, the experts recommend switching to any of the great mineral options available now.

While both mineral and chemical sunscreens can lead to a skin reaction, contact dermatitis is more common with chemical sunscreens, He says. So, generally, folks with sensitive skin or conditions like rosacea, eczema or psoriasis may want to stick with mineral sunscreens.

Who can benefit from chemical sunscreens?

Chemical sunscreens have a lot of advantages and may be the perfect option for some people.

They tend to have a more "cosmetically elegant" formula, He says, which means they'll feel nicer on the skin and often blend into a wider range of skin tones than mineral sunscreens. "Patients with darker skin tend to really have a hard time with mineral sunscreens," Waldman agrees, and find that chemical sunscreens don't usually leave the same pasty hue behind.

While dermatologists generally recommend mineral sunscreens for those with sensitive skin, He notes that those products can sometimes be harder to remove at the end of the day. So some people with sensitive skin may actually prefer chemical sunscreens, she adds.

It all boils down to finding the right sunscreen for you, which should be one that you enjoy enough to use every single day. And, if you happen to love a chemical sunscreen, you don't need to throw it away.

Based on the data available right now, chemical sunscreens are a totally fine choice, He says. "There will probably be more studies in the future to further flesh out this issue," she adds, "but as everything stands right now, chemical sunscreens are very safe."

This article was originally published on TODAY.com