Use of hair dye associated with uterine fibroids in Black women, study finds

Source: www.ewg.org By Alexa Friedman, Ph.D. (EWG)

Using hair dye may be linked to developing non-cancerous tumors in the uterus, particularly among Black women, a recent study suggests.

By age 50, around 70% of women have at least one of these tumors, known as uterine fibroids. Most do not show symptoms, but the presence of fibroids may lead to health effects like worse or heavier periods, pelvic pain and fertility issues. These fibroids are diagnosed more often in Black women compared to white women.

The study analyzed the potential association between hair dye use and presence of fibroids in almost 900 Black women ages 26 to 39 in the greater Detroit area. The research was published by Fertility and Sterility, a peer-reviewed journal of the Association Society of Reproductive Medicine.

Women who reported having used any type of hair dye in the past year had a 44% increase in risk of fibroids than women who had not reported use, the study found. The research was led by a team from Boston University School of Public Health, the National Institute of Environmental Health Sciences, in Durham, N.C., and Henry Ford Health, in Detroit.

The authors found the highest increase in risk in the presence of fibroids occurred with reported use of fades, a semi-permanent dye (98% increase in risk). The use of bleach, frost or highlights was also reported to increase risk by 36%.

Chemicals in hair dye

The study didn’t assess how specific hair dye ingredients may be linked to uterine fibroids. But an earlier study by the same researchers showed hair product use was associated with greater concentrations in the body of multiple chemicals that can interfere with the hormone system. 

Several of these chemicals can harm the reproductive system, including uterine fibroids, changes to menstruation, polycystic ovary syndrome, and hormone-dependent cancers like breast cancer.

A 2024 EWG analysis of over 500 hair dyes also found that some common chemicals used to create the dye color and hold ingredients together, such as resorcinol and m-aminophenol, had health concerns, including disruption of the hormone system. The report analyzed data from EWG’s Skin Deep®, our free searchable public database of over 130,000 personal care products and their ingredients.

Hair dyes often contain ingredients like isothiazolones or formaldehyde releasers to prevent the growth of microbes. Both types of ingredients have been associated with irritation and allergies.  

Dyes also often contain fragrance but the word “fragrance” or “parfum”  refers to a mixture of potentially hundred or more chemicals. Often these chemicals are not on the label. Some fragrance compounds are endocrine disruptors but have also been associated with allergies, skin irritation, respiratory distress and potential harm to the reproductive system.

Other health risks 

The study is the first to examine hair dye in relation to uterine fibroids. But other research has reported on other potential health harms associated with hair dye and hair product use. 

Several studies have identified hair dye use with increased risk of some cancers, and the International Agency for Research on Cancer concluded that workplace exposure to the chemicals used by a hairdresser or barber is “probably carcinogenic to humans.” 

Additional studies report an association between the use of hair dye and a higher risk of several cancers in non-workplace settings, including breast and ovarian cancer.

Hair dye use can also cause rashes and allergic reactions, not only to the people who dye their hair but also to the salon workers who apply it. Hair dyes are one of the most frequent sources of allergic reactions for both hairdressers and consumers.

Inequitable harms

The new study included 868 women, but just 149 women had fibroids. The small size of the study means that this association needs to be confirmed in additional studies. This is the first study to examine hair dye use and fibroids in Black women, a notable finding, since Black women have a higher incidence of fibroids, but the reason why is not known. 

EWG’s analysis supports the hypothesis that health disparities could be related to differences in product hazard scores. EWG’s 2025 report on products marketed to Black women found disparities in the availability of safer personal care products. Using data from Skin Deep, EWG found that products marketed to Black women were, on average, more hazardous than products with no demographic marketing. 

Studies that have measured the concentration of certain personal care product chemicals in the body have also consistently reported that concentrations are higher in Black women, compared to white women.  

And research has also reported that hair-dye-related cancer risk may be higher among Black women, compared to white women. One study reported that use of permanent hair dye was associated with a 45% higher breast cancer risk among Black women, compared to white women.

What you can do 

While EWG continues to advocate for stronger government regulations that ensure product safety and decrease exposure disparities, consumers can also take action to reduce their exposure to harmful chemicals in products. Making safer choices or limiting use, when possible, can help reduce risk. See our tips on safer hair dye use. 

Using Skin Deep and reading ingredient labels can be helpful in avoiding products that contain harmful chemicals, such as resorcinol and m-aminophenol, and may help reduce health risks. 

Avoiding sensitizers like isothiazolones (ingredients that end with -thiazolone, like methylisothiazolinone), as well as formaldehyde releasers like imidazolidinyl urea and DMDM hydantoin, can help reduce irritation and allergy concerns. To learn more, read our in-depth report on chemicals found in hair dye.

Consult our Healthy Living app to find less hazardous products when you’re on the go. If you do not see your product in Skin Deep, you can submit products to the Skin Deep database in the app or send questions to skindeep@ewg.org.