TOPLINE: 

A systematic review of 96 studies found that long-term use of hair dyes, especially darker shades, was associated with an increased risk for certain cancers, varying by age, gender, race, genetics, and pregnancy or lactation status.

METHODOLOGY:

• This systematic review included 96 studies (from PubMed and MEDLINE databases) investigating hair dye exposure as a risk factor for any type of cancer, published between January 1964 and March 2025.
• The review included 13 prospective cohort studies and 83 case-control studies, including two with adults and children and five on maternal exposure and pediatric risk for cancer.
• The associations between use of hair dye and the risk for cancer were assessed.

TAKEAWAY:

• Most studies reported a direct association between the use of hair dye and the risk for breast cancer. Black women who regularly used dark shades of permanent hair dyes showed a 72% increased risk for estrogen receptor-positive breast cancer, while light-colored dyes were associated with a significantly increased breast cancer risk among White women. One study reported an increased risk for nonserous ovarian tumors in women exposed to permanent hair dye in the prior 12 months.
• While some studies found no significant association with bladder cancer and use of hair dyes, a population-based study found that the risk for bladder cancer increased with use of hair dye for more than 31 years in women. Two studies found that individuals carrying slow acetylation NAT2 genotypes or specific CYP1A2 genotypes showed an elevated risk.
• Several studies found that maternal use of hair dye in early pregnancy and lactation increased the risk for acute lymphoblastic leukemia in offspring. In one study, the risk for prostate cancer was increased — especially in men younger than 60 years — with use of hair dyes for more than 10 years, starting before 1980.
• In some studies, use of hair dye was associated with an increased risk for hematopoietic cancers, such as leukemia, myelodysplastic syndrome, and non-Hodgkin’s lymphoma; and brain tumors (glioma and glioblastoma multiforme).

IN PRACTICE:

"Despite inconsistencies among the studies, the link between hair dye use and cancer risk cannot be overlooked," the authors concluded, noting that "additional studies are needed to evaluate the safety of current hair dye formulations and their long-term health effects." Some data suggest, they added, that modern hair dye formulations, which do not contain aromatic amines included in hair dyes before 1980, “may not confer the same level of risk.” 

SOURCE:

The study was led by Rachel K. Greene, MD, Department of Dermatology, University of California Irvine, Irvine, and was published online on October 25 in JAAD International.

LIMITATIONS:

The review included studies with heterogeneous endpoints, small sample sizes, potential recall bias, retrospective data collection, and the inclusion of older hair dye formulations that may not reflect current products.

DISCLOSURES:

No funding sources were reported for this study. The authors reported having no relevant conflicts of interest. 

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.