Sunscreen and Breast Cancer Risk: What You Need to Know
Sunscreen is an important tool for skin cancer prevention. It works by blocking or absorbing the UV rays that cause skin cancer.
There have been concerns in recent years about sunscreen itself causing cancer. But there’s no clear evidence that using sunscreen increases your risk of breast cancer — or any cancer.
On the other hand, unprotected sun exposure does greatly increase your risk of skin cancer. Skin cancer is the most common form of cancer, and research shows sunscreen can help prevent it. And while it’s true that there are concerns about chemicals used in some sunscreens, there are still plenty of safe options. If you’re spending time in the sun, the benefits of using sunscreen will almost always outweigh any risks.
The benefits of sunscreen
Sunscreen is one of the best tools we have to prevent skin cancer, besides limiting sun exposure.
“UV radiation is a known human carcinogen. We know that too much sun can cause skin cancer," says Apple Bodemer, MD, associate professor of dermatology at the University of Wisconsin School of Medicine and Public Health. “Just one sunburn every two years can triple your risk of developing melanoma (a potentially deadly type of skin cancer). Regular sunscreen use has been shown to decrease rates of skin cancer. In the case of squamous cell skin cancer, by as much as 40%.”
A study of nearly 10,000 people linked using sunscreen to a significantly lower risk of skin cancer. Another study of over 100,000 women linked sunscreen use to an 18% lower risk of melanoma. There haven’t been studies of how effective sunscreen is among people who are not white. However, sunscreen has been shown to reduce skin damage from UV light in people with darker skin, and in theory, that means it should reduce skin cancer
There has been some indirect and inconclusive evidence that some ingredients in chemical sunscreens may have concerning health effects, like possibly affecting people’s hormones. Although some hormone changes can increase the risk of breast and other cancers, there’s currently no link between chemicals in sunscreen and breast cancer risk.
Types of sunscreen
There are two kinds of sunscreen: physical and chemical.
Also called mineral sunscreens, physical sunscreens use sun-blocking ingredients like zinc oxide and titanium dioxide. They sit on top of the skin and reflect the sun’s UV rays so that they don’t damage the skin.
Research shows that zinc oxide and titanium dioxide are safe and effective for blocking UV rays and preventing skin cancer. Zinc oxide and titanium dioxide are not absorbed through the skin into the bloodstream.
Chemical sunscreens contain ingredients like avobenzene and oxybenzone (also known as benzophenone-3 or BP-3). These chemicals get absorbed into your skin, where they absorb UV rays so that they don’t damage the skin.
Most concerns about cancer risk have focused on ingredients in chemical sunscreens.
What the research shows
The main concerns about some ingredients in chemical sunscreens are:
Because they’re absorbed into the skin, they can pass through it into the bloodstream and circulate through the body. However, the health effects of this absorption are still unknown.
Some research studies suggest oxybenzone may be an endocrine disruptor (meaning it interferes with the body’s hormones), but the results have been inconclusive.
Some sunscreen sprays have been found to be contaminated with benzene, a chemical that increases the risk of blood disorders and leukemia.
In the US, sunscreens are regulated by the Food and Drug Administration (FDA). In 2021, the FDA updated their requirements for sunscreens, noting that zinc oxide and titanium dioxide met their strict standards for being safe and effective for sunscreen use. The requirements called for more safety information from industry on the remaining 12 common sunscreen ingredients, including avobenzone and oxybenzone. However, the FDA notes that this recommendation does not mean these ingredients are unsafe in sunscreens.
If you’re concerned about the ingredients found in chemical sunscreens, you can avoid them by opting for physical (or mineral) sunscreens.
Some studies have looked at how some ingredients in chemical sunscreen may affect hormones. Much of the research has centered on oxybenzone. Oxybenzone is also found in other personal care products, like body lotions, and in some plastics, but chemical sunscreens seem to be the biggest source of human exposure. Some studies suggest that exposure to oxybenzone may affect estrogen levels in human cells and mice, but in general, research is inconclusive and unclear.
The Food and Drug Administration (FDA) has called for more research on this before it can designate oxybenzone as generally safe and effective. At the same time, it has not found enough evidence in the existing research to revoke authorization and phase-out use of oxybenzone.
A 2020 study by FDA scientists found that six main ingredients in chemical sunscreens — including avobenzone, octocrylene, homosalate, octisalate, octonoxate and ecamsule, and oxybenzone — can be absorbed into the bloodstream at levels that are above the FDA’s proposed safety threshold. The study highlighted how even a single application of lotion, aerosol spray, non-aerosol spray or pump spray sunscreen products resulted in measurable blood levels of the main chemical ingredients.
The FDA emphasized that more research is needed to determine the health effects of chronic use of these ingredients. “The fact that an ingredient is absorbed through the skin and into the body does not mean that the ingredient is unsafe,” the FDA said in a press release following the release of the study.
Benzene is not used as an ingredient in sunscreen, but can be introduced to sunscreens during the manufacturing process. Occasionally, aerosol sunscreens or other skincare products may become contaminated with benzene, and there have been a few occasions — in 2021, 2022, and 2023 — when sunscreens were recalled by the FDA because of detected benzene contamination.
But while exposure to benzene has been shown to increase the risk of developing leukemia and other blood disorders, the data on benzene in skincare products is generally inconclusive.
Even the FDA acknowledged in announcing the sunblock recalls that the amounts detected “would not be expected to cause adverse health consequences based on generally accepted exposure modeling” but that the recalls were done out of an abundance of caution. More research is needed, but there’s currently no evidence that small amounts of benzene in skincare products increases cancer risk.
It’s worth noting that benzene is all around us: We’re likely exposed to it every day from outdoor air, which is polluted with benzene from cigarette smoke, car emissions, forest fires, and the burning of fossil fuels. Benzene is also used to make Styrofoam, nylon, dyes, and detergents, among other things.
What to do if you’re concerned about sunscreen and cancer risk
Be sure to use some sort of sun protection, because the risks of skin cancer from sun exposure far outweigh the other possible health risks from chemical sunscreen. This is true for people with darker skin, as well as for those with lighter skin.
If you’re worried about the effects of chemical sunscreens, use physical (mineral) sunscreens instead. But any sunscreen is safer than nothing — It’s important to protect yourself against the very real and established risk of skin cancer from UV exposure.
Also, remember that sunblock is just one way to protect yourself from the sun. Other good practices include:
staying indoors, or in the shade, between 10 a.m. and 2 p.m. (11 a.m. and 3 p.m. during Daylight Savings Time), to avoid the strongest sunlight
wearing a hat with a brim to protect your face and neck
wearing protective clothing that’s tightly woven (especially long-sleeved shirts, or rash guards when you’re swimming); some clothing manufacturers, particularly those that make outdoor gear, list the ultraviolet protection factor (UPF) of clothing they sell (the higher the UPF, the better)
— Last updated on July 30, 2025 at 3:15 PM