Benzoyl Peroxide Not Linked To Increased Risk Of Benzene-Related Cancer, Studies Show

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Chances are, you're one of the millions of people who have used an acne-fighting ingredient called benzoyl peroxide at some point during your life. While the medication has come under fire in the past year for potentially causing cancer, recent population-based studies have largely put that association to rest.

"The questionable link between benzoyl peroxide and cancer stems from a chemical called benzene, which is a known carcinogen that's found in cigarette smoke, gasoline and crude oil products," says Jesse Veenstra, M.D., Ph.D., a dermatologist at Henry Ford Health. "It's most strongly associated with certain blood cancers like acute myeloid leukemia. Research has shown that over time and under high temperatures, some formulations of benzoyl peroxide can break down into benzene. However, even in such cases, the resulting benzene exposure is likely minimal. Benzoyl peroxide has been used for decades and there haven't been any clear risks identified between benzoyl peroxide use and benzene-related cancers, or any other cancers."

A Deeper Dive Into Research About Benzoyl Peroxide, Benzene And Cancer

Last year, studies from an independent lab found that some formulations of benzoyl peroxide degrade into benzene. (Depending upon whether it's a cleanser, lotion, spot treatment, etc. - along with other factors - the formula can change the chemical nature of the product and some can become more susceptible to degradation than others.) The researchers petitioned the Food and Drug Administration (FDA) to pull products containing benzoyl peroxide from the market. The FDA conducted its own research and recently released their findings.

"The FDA tested 95 different products and more than 90% of them had no levels or negligible levels of benzene," says Dr. Veenstra. "They did find a few products that had elevated benzene levels, which were then voluntarily recalled from retail shelves. (That list is here.) But even with those products, the risk is still theoretical - there have been no real-world studies showing a link between benzoyl peroxide and cancer."

Dr. Veenstra and his team also recently conducted a study using a patient database containing more than 260 million electronic medical records across the United States and found no association between benzoyl peroxide and benzene-related cancers.

"We compared acne patients who had prescriptions for benzoyl peroxide with acne patients who didn't have prescriptions for benzoyl peroxide," says Dr. Veenstra. "We also compared patients who had acne with patients who didn't have acne. We assessed outcomes of benzene-related cancers - accounting for factors like age, sex, race, smoking and alcohol use - to see if there were any risks associated with benzoyl peroxide. We didn't find a link. Other groups have conducted similar studies with other large patient databases and have found comparable results. While these studies are not perfect, their findings are reassuring, suggesting that the real-world use of benzoyl peroxide is unlikely to be associated with an increased risk of cancer."

It's worth mentioning, however, that a recent report from FAERS (FDA Adverse Event Reporting System) did find a potential increased cancer risk with benzoyl peroxide use. However, this report has major caveats, says Dr. Veenstra.

"FAERS is a self-reported database that's unverified by medical documentation," he says. "It has many limitations. And when the authors of this study aggregated this FAERS data, they used a time frame between 2019 and the first quarter of 2024. But the first quarter of 2024 was when the news release came out about benzoyl peroxide degrading into benzene. It's no coincidence, then, that is also when most of the self-reported associations between benzoyl peroxide and cancer occurred (more than 50% of cases from the study). This is called stimulated reporting bias and strongly influenced the study's results. It's also important to note that the study did not include FAERS data from earlier years, despite it being available, which raises concerns about data selection bias."

With Dr. Veenstra's findings, he recently submitted a response to the FAERS report. "We advised that their results should be interpreted very cautiously, as there were substantial limitations and biases in the study that were not fully discussed by the authors. We hope that dermatologists and patients rely on the larger well-done studies that have been completed thus far, along with the American Academy of Dermatology's recent guidance."

How To Safely Store And Use Products Containing Benzoyl Peroxide

Out of an abundance of caution, the American Academy of Dermatology (AAD) released new guidelines for using benzoyl peroxide:

• Store benzoyl peroxide products according to the manufacturer's instructions at room temperature or in a refrigerator.
• Replace products that contain benzoyl peroxide every 10 - 12 weeks.
• Discard benzoyl peroxide products if they're exposed to temperatures higher than 78 degrees Fahrenheit.

If you are still concerned about using acne products containing benzoyl peroxide, the AAD recommends switching to other acne-fighting ingredients such as retinoids, salicylic acid or azelaic acid. And, as always, you can always make an appointment with your dermatologist to discuss concerns and find a skin care regimen that's right for you.

Reviewed by Jesse Veenstra, MD, PhD, MS, FAAD, a board-certified dermatologist who sees patients at Henry Ford Medical Centers - Ford Road and New Center One.

Categories : FeelWell

Tags : Cancer, Dermatology, Skin Care, Jesse Veenstra