Published March 2026

Hair Relaxers and Uterine Fibroids: The Research Explained

Last updated: June 2026

Uterine fibroids — noncancerous growths in the uterus — affect up to 80% of women by age 50, but the rates are significantly higher among Black women. A growing body of research suggests that one factor contributing to that disparity may be long-term use of chemical hair relaxers.

What Are Uterine Fibroids?

Uterine fibroids (also called leiomyomas or myomas) are benign tumors that grow in or around the uterus. While they are not cancerous, they can cause severe symptoms that profoundly affect quality of life: heavy menstrual bleeding, pelvic pressure and pain, frequent urination, difficulty getting pregnant, and complications during pregnancy. Severe cases often require surgical intervention — including myomectomy to remove fibroids or hysterectomy to remove the uterus entirely.

Black women develop fibroids at two to three times the rate of white women, develop them at younger ages, and experience more severe symptoms. Researchers have long sought to understand the causes of this disparity beyond genetics alone.

What the Research Shows About Hair Relaxers

Multiple studies have examined the relationship between hair relaxer use and uterine fibroids, with consistent findings suggesting an elevated risk for frequent, long-term users.

A landmark 2012 study published in the American Journal of Epidemiology followed over 23,000 Black women in the Black Women's Health Study and found that women who used hair relaxers at least seven times per year for more than two years were 17% more likely to develop uterine fibroids than those who didn't use relaxers. Women who experienced scalp burns from relaxer application — a common occurrence — had even higher rates.

More recent research has gone deeper into the mechanisms. Chemical hair relaxers contain endocrine-disrupting chemicals (EDCs) — primarily phthalates, parabens, and bisphenol A — that interfere with the body's hormone-signaling systems. Since uterine fibroid growth is strongly driven by estrogen and progesterone, chemicals that disrupt hormonal signaling are biologically plausible causes of fibroid development and growth.

The Role of Endocrine-Disrupting Chemicals

Endocrine disruptors work by mimicking natural hormones, blocking hormone receptors, or interfering with hormone synthesis and metabolism. In the context of uterine fibroids, the concern is that EDCs in hair relaxers may:

• Increase estrogen activity in uterine tissue, driving fibroid cell proliferation
• Reduce the body's ability to break down and eliminate estrogen normally
• Interact with progesterone pathways that regulate uterine cell growth
• Create cumulative effects from decades of repeated exposure starting in childhood

Hair relaxers are applied directly to the scalp and left on for extended periods — typically 20 to 45 minutes — allowing chemicals to be absorbed through the skin. Unlike food-borne EDC exposure, this is direct dermal absorption near a rich blood supply in the scalp, potentially delivering significant chemical loads systemically.

Why Childhood Use Matters

Many Black girls are introduced to chemical hair relaxers at a very young age — often before age 10, and sometimes as young as 4 or 5 years old. Extended use from childhood through adulthood means decades of chemical exposure during critical developmental periods. Endocrine-disrupting chemical exposure during childhood and adolescence, when hormonal systems are developing, may have particularly lasting effects on reproductive system function.

In the context of the hair relaxer lawsuit (MDL 3060), women who began using relaxers in childhood and continued into adulthood may have stronger causation arguments than those who used products only briefly as adults, because the cumulative exposure period is longer and began during a vulnerable developmental window.

Qualifying for a Claim: Fibroid Severity Matters

Not every uterine fibroid diagnosis will qualify for a claim in MDL 3060 or related state litigation. Courts and plaintiff legal teams have developed eligibility criteria that generally require significant, documented medical impact from fibroids. Cases most likely to qualify include:

• Fibroids requiring surgical treatment — myomectomy or hysterectomy
• Fibroids causing significant documented symptoms requiring ongoing medical management
• Fibroids resulting in fertility complications or pregnancy loss

Women with incidentally discovered fibroids that never caused symptoms or required treatment are less likely to meet the injury threshold. An attorney can help you assess whether your specific medical history meets the criteria.

Documenting Your History for a Fibroid Claim

If you believe your fibroid diagnosis may be connected to hair relaxer use, documentation is your most important asset. You'll want to gather medical records documenting the diagnosis, any imaging (ultrasound, MRI), treatment records including surgical reports, and records of how fibroids affected your daily function and quality of life. Pair this with as complete a hair relaxer use history as possible — brands, frequency, years of use, and how early you started.