Deodorant and antiperspirant cause breast cancer

What we know

The claim that deodorants or antiperspirants cause breast cancer typically rests on two related concerns: that aluminum-based compounds used in antiperspirants to block sweat glands are absorbed through the skin and act as a hormone-disrupting or carcinogenic agent, and that underarm shaving combined with antiperspirant use allows chemicals to enter the body through small skin nicks and lymphatic tissue located close to the breast. Both concerns have been investigated directly in epidemiological and toxicological research.

The National Cancer Institute, part of the US National Institutes of Health, states that no conclusive scientific evidence links antiperspirant or deodorant use to the development of breast cancer, after reviewing the existing body of case-control and cohort studies on the topic. A frequently cited 2002 case-control study published in the Journal of the National Cancer Institute, examining more than 1,600 women, found no association between antiperspirant or deodorant use, including frequency of use and use combined with underarm shaving, and breast cancer risk, directly testing the specific mechanistic pathway proposed by the theory.

Regarding aluminum specifically, the compounds used in antiperspirants, primarily aluminum chlorohydrate and related salts, work by forming a temporary physical plug in sweat ducts rather than being absorbed in meaningful quantities into the bloodstream or breast tissue. Studies measuring actual aluminum absorption through skin application find only very small amounts enter the body, far below levels associated with any demonstrated toxicological harm, and the European Scientific Committee on Consumer Safety, after a dedicated review, concluded that aluminum in antiperspirants at the concentrations typically used in commercial products does not pose a risk of breast cancer to consumers.

Some smaller, more preliminary studies have detected trace aluminum in breast tissue samples taken from cancer patients, findings sometimes cited as suggestive evidence for the theory. However, the American Cancer Society and cancer epidemiologists reviewing this literature note that detecting trace levels of a common environmental element in tissue does not establish that the element caused the cancer, since aluminum is naturally present in food, water, and numerous other everyday consumer products entirely apart from antiperspirant use, and these smaller studies have not been replicated in larger, well-controlled trials designed to test causation directly.

The geographic pattern of breast cancer often cited anecdotally, that most breast tumors occur in the upper outer quadrant of the breast closest to the underarm, is fully explained by the simple anatomical fact that this region of the breast naturally contains a greater volume of glandular breast tissue than other quadrants, meaning tumors are more likely to arise there regardless of any product applied nearby, a straightforward anatomical explanation rather than evidence of a causal link to antiperspirant exposure. The claim has shown notable persistence in online health communities partly because breast cancer is common and deeply feared, and antiperspirant is a near-universal daily product, which makes a proposed causal link between the two feel intuitively plausible even though large controlled studies specifically designed to test that link have not found supporting evidence. Ongoing surveillance by cancer registries in multiple countries over several decades, spanning the period of near-universal antiperspirant adoption, has not detected a corresponding rise in breast cancer incidence that would be expected if such a widely used product carried a meaningful carcinogenic effect, adding further population-level context to the individual study findings described above.

Common claims

• Aluminum in antiperspirants causes breast cancerNot supported by case-control studies or European Scientific Committee review
• Shaving underarms before applying antiperspirant lets carcinogens into the breastNot supported, the 2002 JNCI study tested this specific mechanism and found no association
• Most breast tumors form near the underarm because of deodorant useFalse, explained by higher glandular tissue density in the upper outer breast quadrant

Evidence hierarchy

All sources

• Antiperspirants/Deodorants and Breast CancerNational Cancer Institute (NIH) · 2023
• Antiperspirant/Deodorant Use and the Risk of Breast CancerJournal of the National Cancer Institute · 2002
• Scientific Committee on Consumer Safety, Opinion on AluminiumEuropean Commission · 2020
• Antiperspirants and Breast Cancer RiskAmerican Cancer Society · 2023

Related terms