The link between hair straighteners and uterine cancer

By Jules Murtha | Medically reviewed by Nitin Chandramouli, MD FACP
Published March 24, 2023

Key Takeaways

  • Past research shows that the use of some hair products, including relaxers and pressing products, may be associated with the development of ovarian cancer.

  • Now, a new study indicates that the use of hair straighteners may also be linked to uterine cancer.

  • Factors that reduced the risk of uterine cancer, according to the CDC, include using birth control pills, exercising regularly, maintaining a healthy weight, and taking progesterone as necessary.

It’s no secret that certain hair products have carcinogenic properties. Hair straighteners, relaxers, and pressing products are just a few examples of hair products that have known associations with hormone-sensitive cancers—including ovarian and breast cancers—in those who use them, studies say.

But hair straightening products may also be linked to the development of a third type of cancer: uterine. In order to reduce the risk of uterine cancer in patients, doctors may want to let them know about this latest research, as well as remind them to exercise regularly and take hormonal medications as needed.

A link between hair straighteners and uterine cancer?

For years, research has revealed the association between hair straightening products and hormone-sensitive cancers.

One 2021 study, for example, published by Carcinogenesis, found that the use of hair straighteners, relaxers, and pressing products more than four times per year was linked to a higher risk of ovarian cancer (HR = 2.19; 95% CI: 1.12–4.27).[]

When it comes to uterine cancer, new research points to a similar connection.

A 2022 study, published by the Journal of the National Cancer Institute, looked at the relationship between hair products that may have endocrine-disrupting and carcinogenic properties and the risk of uterine cancer.[]

Data were collected from 33, 947 participants between the ages of 35 and 74, of various races and ethnicities, who self-reported their use of hair products (hair dyes, straighteners, relaxers, pressing products, and permanents or body waves) in the previous year.

Over an average follow-up of 10.9 years, the researchers identified 262 medically confirmed uterine cancer cases among the participants (94.7% of which were classified as endometrial cancers).

Women who reported no use of hair straightening products in the year prior to baseline formed the comparator group. Nearly 1.64% of these women were predicted to develop uterine cancer by the time they turned 70.

The results of the analysis showed that the estimated risk of uterine cancer among women who reported some use of hair straightening products was 1.18% higher than the risk among women who didn’t use them at all.

Frequent use raised the risk further: Women who reported using the products more than four times per year had a 2.41% increased risk of uterine cancer vs those who reported no use.

These findings, therefore, are the first to provide evidence of a potential association between the use of hair straightening products and uterine cancer—although the evidence is distinctly limited.

As noted in the study, future research is required not only to replicate the findings, but also to pinpoint the specific chemicals that may have produced the perceived association.

Other experts have also voiced concerns about the thoroughness of the study.

In a published response, one researcher, Mahyar Etminan, PharmD, MSc, highlights three additional limitations: the lack of a lag-time analysis, the potential influence of residual confounding on the results, and the exclusion of data pertaining to cardiovascular disease, which may have produced bias.[]

The authors of the study acknowledge that further research in this area is needed before researchers can draw any concrete conclusions regarding this potential link.

“More research is warranted,” they wrote, “to confirm our novel findings in different populations, particularly in African American and/or Black women because of the high prevalence of straightener use, and to evaluate the potential contribution of hair products to health disparities in uterine cancer.” 

Reducing the risk of uterine cancer

Avoiding hair straightening and similar products may be one way that women can reduce their risk of uterine cancer, but there are other ways that physicians can suggest to their patients,  based on studies.  

The CDC acknowledges that there is no sure-fire way to prevent uterine cancer. However, patients who want to cut down their risk of developing it, they say, can do so by exercising regularly and maintaining a healthy weight.[]

The use of birth control pills can help as well, as can taking progesterone, when taking estrogen.

Other sources echo and expand on these tips.

A review article published by Current Oncology Reports covered many issues related to the occurrence of uterine cancer.[]

Obesity and weight cycling in middle age, for example, are notable risk factors for endometrial cancer. In individuals with obesity, bariatric surgery, followed by maintaining a healthy, stable weight, can mitigate risk by up to 81%. 

Certain forms of contraception may play a role in prevention. 

The use of combined oral contraceptives may provide durable protection against endometrial cancer for at least 30 years. Similarly, the use of the levonorgestrel intrauterine system (LNG-IUS) and inert intrauterine devices also reduces the risk.

Bisphosphonates have been shown to reduce the risk of endometrial cancers by 56% with at least 3 years of use.

Finally, even coffee has entered the picture. Patients may be happy to know that one cup of caffeinated coffee per day has been shown to decrease the risk of endometrial cancer by up to 7% (4% for decaffeinated). A cup of green tea per day has been linked with an 11% reduction in risk.

Overall, the research on the relationship between certain hair products and hormone-sensitive cancers is still underway. For now, you may help patients take their health into their own hands by running them through the strategies they can employ to reduce their risk of uterine cancer.

What this means for you

Past studies have clearly linked the endocrine-disrupting and carcinogenic properties of hair products—specifically, hair straighteners and relaxers and pressing products—to breast cancer and ovarian cancer. Researchers have now discovered an association between the use of hair straightening products and the development of uterine cancer. In order to help patients reduce their risk of uterine cancer, you may make them aware of this research, as well as recommend regular exercise and the use of birth control or hormonal medications as needed.

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