What the Science Really Says About Chemical Relaxers

Chemical relaxers have been part of textured hair culture for generations, and the conversation around them has usually focused on strand damage: breakage, thinning, and scalp burns. In recent years, large-scale research has expanded that conversation into territory that deserves clear, calm attention: systemic health effects tied to frequent use.

What the Research Found

A widely cited study published in the Journal of the National Cancer Institute (2022) followed a large cohort of women over more than a decade and found that frequent use of chemical hair straighteners was associated with a meaningfully higher incidence of uterine cancer compared to non-users; researchers estimated roughly a 4% cumulative incidence by age 70 among frequent users, compared to about 1.6% among non-users. The study did not prove causation, but the association was strong enough, and the products' hormone-disrupting ingredient profiles plausible enough, that researchers called for further investigation and consumer awareness.

Why This Disproportionately Affects Black Women

The same research base, including data from the long-running Sister Study cohort, has repeatedly found that Black women use chemical relaxers at significantly higher rates and often starting at younger ages than other groups, a pattern shaped as much by decades of professional and social pressure around hair texture as by personal preference. That usage pattern means any health risk tied to frequent relaxer use lands disproportionately on Black women, making this a hair health issue and a broader health equity issue at once.

What This Means for Your Routine

This isn't a call to panic or to shame anyone's styling choices; relaxers remain a personal decision. It is a case for informed decision-making: understanding ingredient lists, reducing frequency where possible, ensuring proper scalp protection during application, and treating relaxer use as a decision worth revisiting periodically as new research emerges, rather than a permanent, unquestioned routine.

Go Deeper: The Science in Rooted

Rooted covers this research in full, including the chemistry of how relaxers alter the hair fiber and the broader health literature every textured-hair woman deserves to know. Dr. Olusola Idowu presents the evidence clearly, without judgment, so you can make the choice that's right for you. Get Rooted on Amazon →