The Connection Between Hair Relaxers and Cancer

When researchers discovered hair relaxer use was linked to elevated cancer risk, it raised urgent questions about what’s inside these products and what exposure might mean for women’s long-term health.

Studies on hair relaxers and cancer have suggested that frequent users of these products face a significantly higher risk of uterine, ovarian, and endometrial cancer. This information helped increase public awareness of potentially harmful consumer goods and provided attorneys with valuable insights for litigating against these cosmetic brands.

Read on to learn what studies found, which chemicals are involved, and how scientific evidence helps support the lawsuits against hair relaxer brands.

Relaxers can be divided into two main categories: lye and no-lye. Lye relaxers contain the active agents of sodium or potassium hydroxide, while no-lye formulas use calcium or lithium hydroxide for the straightening mechanism.

These variations change the formula slightly, and some users were led to believe that no-lye was safer due to how it was marketed, but neither formula removes the potential health risks. Both relaxer formulas can contain additives and ingredients used to stabilize the formula, preserve the product, or enhance the fragrance.

These compounds, including phthalates, parabens, and heavy metals, have been identified as Endocrine-Disrupting Chemicals (EDCs) and are known to interrupt hormone signaling and regulation, contributing to abnormal cell growth and hormone-sensitive cancers.

The strongest, most widely discussed risk that hair relaxers are linked to is uterine cancer. In a large NIH-supported study, using data from an earlier Sister Study, women who reported using relaxers had a higher risk of uterine cancer by more than double that of those who did not report using them. This is why a diagnosis of uterine cancer is a prime qualification for a hair relaxer lawsuit.

Scientists are continuing to examine possible links, particularly in individuals with long-term exposure. Because reproductive organs are strongly influenced by hormones, scientists continue to reveal connections between hair relaxers and ovarian cancer.

In product liability cases, attorneys often rely on scientific studies to demonstrate whether a product could plausibly contribute to an illness. Scientific research offers several possibilities for how chemical relaxers could contribute to cancer risk over time. This information strengthens causation—the link between hair relaxers and hormone-related cancer—and provides evidence to help these claims meet strict legal standards.

Assumptions that connect hair care compounds to cancer also consider the duration of exposure across hormone-sensitive pathways. The history of use, duration, and severity of harm are foundational to the litigation against hair care brands, and all of these factors rely on research to connect the dots.

Courts require plaintiffs to show that their specific illness was “more likely than not” caused by product use rather than genetics or lifestyle. Demonstrating material case facts and showing hair relaxers are linked to cancer may require multiple forms of research, including:

• Epidemiological studies examining cancer rates among relaxer users
• Toxicology research on chemical ingredients
• Endocrine disruption studies involving hormone-related cancers
• Medical expert testimony explaining biological mechanisms
• Healthcare records and diagnostics showing how plaintiffs have been harmed by cancer linked to hair relaxer use

While each case is evaluated individually, all claims rely on science to establish exposure patterns and outcomes between using hair relaxers and ovarian, uterine, and endometrial cancers.

Research into the health risks associated with chemical hair relaxers is still evolving, but existing studies have raised important questions about the safety of these products and the responsibilities of manufacturers.

If you or a loved one developed uterine, ovarian, or endometrial cancer after using hair relaxers, speak to our attorneys to learn about your options.