Research suggests people who frequently use chemical hair straightening products are more likely to develop uterine cancer than those who do not use the products.

Some hair straightening products contain chemicals that may act as carcinogens, which can increase the risk of cancer.

Various studies have linked the use of several hair products to hormone-sensitive cancers, including ovarian and breast cancers.

Recent research has found a link between chemicals in hair straightening products and uterine cancer.

Uterine cancer, which doctors also call endometrial cancer, usually starts in the cells of the endometrium, or the lining of the uterus.

This article looks at the link between chemical hair straighteners and uterine cancer, the rates of uterine cancer, how to reduce the risk of uterine cancer, and when to contact a doctor.

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Uterine cancer is one of the most commonly occurring cancers in females in the United States. It begins in the uterus, the female reproductive organ that people also call the womb.

A 2022 study suggests that people who frequently use chemical hair straightening products could have a higher risk of uterine cancer than those who do not use the products.

The study included 33,497 women whom the researchers observed over 11 years. Researchers found the risk of uterine cancer was more than two times higher for participants who used hair straightening products more than four times a year.

Researchers highlighted that Black women may face a higher risk of uterine cancer because they tend to use relaxer and straightening hair products more frequently and from a younger age.

Hair straightening products contain various chemicals that may act as carcinogens. These are substances that can cause cancer.

Which hair straightening products increase the risk of uterine cancer?

Chemical hair straightening, smoothing, and relaxer products that release fumes or gases, such as formaldehyde, upon heating may increase the risk of uterine cancer.

As well as causing the release of formaldehyde in combination with heat, hair straightening products may contain potentially cancer-causing chemicals, such as:

Using heated hair straightening tools combined with chemical straightening products could also increase the risk of exposure due to burns and lesions on the scalp.

Uterine cancer and other types of hair products

According to the 2022 study mentioned above, previous research also found links between various hair products and hormone-sensitive cancers, including ovarian and breast cancer.

This is because the body may absorb carcinogenic chemicals from the products through the scalp, which may result in effects similar to those that the hormone estrogen produces.

However, researchers in the 2022 study found negligible, or statistically insignificant, links between uterine cancer and other hair products, including:

  • bleach
  • temporary dyes
  • highlights
  • permanent dyes
  • semipermanent dyes

According to the Centers for Disease Control and Prevention (CDC), there were 54,744 new cases of uterine cancer in the United States in 2020.

According to the National Institutes of Health, there were 65,950 new cases in 2022.

Research has found that cases of uterine cancer have increased worldwide between 1990 and 2019.

According to the 2022 study mentioned earlier, an estimated 1.64% of participants who did not use chemical hair straightening products would develop uterine cancer by 70 years old. The risk increased to 4.05% for those who frequently used hair straighteners.

Other factors that may increase the risk of uterine cancer include:

  • taking estrogen for hormone replacement therapy
  • having a family history of uterine, ovarian, or colon cancer
  • having the BRCA1 or BRCA2 gene mutation or other gene mutations that increase the risk of uterine cancer
  • having fewer than five periods in 1 year before the onset of menopause
  • having had difficulty becoming pregnant
  • being older than 50 years
  • having obesity
  • taking tamoxifen, a medication for the treatment and prevention of certain types of breast cancer

There is no definitive way to prevent uterine cancer, but researchers believe a person can take certain steps to reduce their risk.

According to the CDC, the following may help reduce the risk of developing uterine cancer:

Not all of the above measures are appropriate for everyone. A person can speak with a doctor about tailored steps they can take to reduce their risk of uterine cancer.

Avoiding the use of chemical hair straightening products may also help reduce a person’s risk of uterine cancer.

A person can contact a doctor if they experience any symptoms of uterine cancer. These can include:

The above symptoms can also occur due to other causes and may not always indicate uterine cancer.

However, any delay in treatment may reduce the likelihood of successful treatment. Receiving a diagnosis as early as possible can help improve outcomes.

According to recent research, people who regularly use chemical hair straightening products may have a significantly higher risk of uterine cancer than the larger population.

Other risk factors for uterine cancer include age, obesity, certain inherited gene mutations, and the use of estrogen in hormone replacement therapy.

Avoiding chemical hair straightening products, taking progesterone with estrogen, and using birth control pills may help reduce the risk of uterine cancer.