Hair relaxing chemically restructures the keratin in afro-textured hair. Burns, breakage, fragility: the immediate risks are well established. Recent studies have also observed statistical associations with fibroids and a possible increased risk of uterine cancer, without proving any causal relationship. Here is what science confirms — and what it still cannot say.
Between cultural heritage, personal choices, and scientific warnings, an investigation into a practice deeply rooted in the intimacy of Black women.
A (too) familiar gesture…
Few gestures are as common — and yet as emotionally charged in the lived experience of many Black women — as hair relaxing. For some, it recalls weekend afternoons when the kitchen turned into an improvised hair salon. For others, it means regular appointments with a neighborhood hairstylist whose experienced hands could transform tightly coiled textures into straight strands within minutes.
The sharp smell of the product, the slow heat rising on the scalp, the careful wait in front of the mirror, the moment when the texture changed beneath the fingers: all sensations engraved in memory. At a time when very few products respected the health of afro-textured hair, relaxing represented for many a practical — almost unavoidable — solution to manage a texture perceived as “difficult,” “unruly,” or “unprofessional.”
For decades, this gesture was presented as self-evident. It accompanied major milestones in life: the start of the school year, job interviews, family events, ceremonies. The idea that straight hair symbolized seriousness, cleanliness, or even beauty profoundly shaped several generations. Hair relaxing thus became an often necessary act for navigating environments where natural textures were misunderstood, infantilized, or poorly perceived.
But behind this normalized, almost silent practice, one essential question long remained unresolved: what does this gesture truly do to the hair — and potentially to the body? What once belonged to private conversations between friends, mothers, and daughters now lies at the center of public discussion, in light of new scientific data.
Altering keratin: what a relaxer really does
Contrary to the idea that relaxing is simply a hairstyling technique, it is in reality a profound chemical transformation. The product does not merely smooth the surface of the hair: it alters the internal structure of keratin, the protein that makes up the hair fiber and determines its shape.
There are two major categories of products. The first includes alkaline relaxers, which rely on highly basic agents. Their mechanism is now well documented: the hair cuticle opens, the agents penetrate deep into the fiber, and break fundamental bonds known as “cystine” bonds. These bonds are responsible for the hair’s natural curl pattern; when weakened or broken, the fiber elongates and loses its original form.
The second family, thio relaxers, works in two stages: internal bonds are broken through a reducing agent, then a new shape is fixed through oxidation. The principle is similar to that of perms, but with denser products designed to precisely guide the fiber during restructuring.
In both cases, the transformation is irreversible for treated lengths. Once the keratin has been modified, the hair never becomes kinky again. Only new growth regains its original texture. This deep chemical alteration explains the effectiveness of relaxing — but also the risks that come with it.
Hair risks: what research clearly establishes
The immediate effects of hair relaxing on the hair and scalp are now well known. Burns are among the most common risks. They occur when a product applied for too long, or in excessive amounts, comes into direct contact with the skin. Some highly alkaline products can cause tingling, tightness, and in the most severe cases, skin lesions.
Scalp irritation is also common. It may appear as redness, persistent sensitivity, itching, or even small wounds. Skin already weakened, or a scalp irritated by other hair practices, increases the likelihood of adverse reactions.
But beyond these immediate effects, it is the impact on the hair fiber itself that raises the greatest concern. Relaxing weakens the hair’s internal bonds, leading to a gradual fragilization of the fiber. Over repeated applications, the hair becomes thinner, less resistant, and more prone to breakage. Everyday actions — brushing, styling, friction — can then trigger significant breakage, sometimes visible within the very first centimeters of the hair lengths.
In some cases, localized hair loss appears, particularly when a scalp burn leaves an area deprived of active follicles. When applications overlap, when overly strong products are used, or when processing times exceed recommendations, these effects may worsen. A cross-sectional study conducted among dozens of users notably reported thinning fibers, significant shedding, recurrent dandruff, and a loss of elasticity in the hair fiber.
These findings, recurrent both in personal testimonies and clinical observations, establish one reality: hair relaxing predictably weakens the hair fiber, proportionally to the frequency of applications and the conditions under which the products are used.
Fibroids: statistical associations, not causation
Two major epidemiological studies conducted several years apart observed a statistical association between the use of hair relaxing products and the risk of developing uterine fibroids. The first, published in 2012, identified a higher risk of fibroids among women who reported regularly using relaxers. The second, published in 2025, expanded the analysis to adolescence — a period of hormonal vulnerability — and identified an increased risk among those exposed at an early age.
In both cases, the results attracted the attention of researchers and the general public alike. A consistent statistical link, especially when observed across multiple studies, calls for vigilance. However, these studies also present several methodological limitations: reliance on self-reported data, lack of precise measurement of products used, variability in formulations between brands, and the possible influence of other environmental factors.
This leads to one precise conclusion: the studies do not demonstrate that relaxers cause fibroids, but they do show that the two phenomena appear together more often than expected. It is a signal, not proof. An element that calls for further research, but should not be overinterpreted.
Uterine cancer: the NIH study raising concerns
In 2022, a study conducted by a major American health institution, the National Institutes of Health (NIH), revealed a notable finding: women who regularly used chemical hair-straightening products showed a higher risk of uterine cancer than those who did not use them. The study immediately drew attention, particularly because the analysis revealed a proportional trend: the more frequent the use, the higher the observed risk.
Here again, the study does not allow for causal conclusions. The biological mechanisms that could explain this link remain unestablished, the exact formulations of the products used are unknown, and the data rely largely on personal declarations.
The authors therefore insist on caution: this is a warning signal, not a verdict.
This distinction is crucial to avoid fueling unjustified fears while still recognizing the importance of continuing research.
Between freedom and information… A personal choice
Hair relaxing is not a trivial gesture. But neither is it a fault, a taboo, or a sign of ignorance. It is a choice, often shaped by history, social environment, persistent beauty standards, and personal preferences.
What matters today is that this choice can be made with full awareness. Scientific data impose nothing: they illuminate. They make it possible to understand immediate hair-related risks, to integrate the statistical signals observed in epidemiological research, and to gain perspective on longstanding practices.
For some, this may mean abandoning relaxers altogether. For others, it may involve more spaced-out or better-supervised use. For still others, it may mean consciously maintaining the practice because it aligns with their reality, style, or needs.
What matters now is that information be transparent, accessible, and honest — freed from the silence that long surrounded this gesture. Hair is an intimate and political part of identity. It tells stories of history, struggle, and desire. Whatever each person’s decision may be, it deserves to be based on facts rather than injunctions or unspoken assumptions.
