Arizona L’Oréal Hair Relaxer Lawsuit Explained

Arizona has sued cosmetics giant L’Oréal over chemical hair relaxers, accusing the company of selling products primarily used by Black women and girls without adequately disclosing research linking frequent use to increased risks of uterine, ovarian and other cancers.

Attorney General Kris Mayes filed the consumer-fraud lawsuit in September 2026 against L’Oréal USA, related L’Oréal entities and SoftSheen-Carson. Arizona alleges the companies knew or should have known about potentially dangerous chemicals and emerging cancer research but continued marketing their relaxers without adequate warnings.

L’Oréal denies that its products cause cancer, says its products undergo rigorous safety testing and argues that the scientific studies cited in hair-relaxer litigation identify associations rather than proving that relaxers cause individual cancers.

Why Is Arizona Suing L’Oréal?

Arizona accuses L’Oréal of violating the Arizona Consumer Fraud Act by selling chemical hair relaxers without adequately warning customers about alleged cancer risks. Attorney General Kris Mayes announced the lawsuit on September 11, 2026. The state says the products contained chemicals it characterizes as potentially toxic or carcinogenic and that epidemiological studies have linked relaxer use with increased rates of several cancers. [Arizona Attorney General]

Mayes alleges L’Oréal knew or should have known about those potential risks and failed to disclose them to consumers. The attorney general says many of the products were marketed primarily to African American women and that some were marketed to children. [Arizona Attorney General]

The allegations have not been proven. L’Oréal disputes the underlying claims about its products.

What Does Arizona Want L’Oréal To Do?

Arizona is seeking civil penalties, monetary relief and changes to how L’Oréal markets hair relaxers. Reuters reported that the state is asking a court to require cancer-risk warnings if the company continues selling the products and is also seeking damages and penalties under Arizona consumer-protection law. [Reuters]

The case differs from many individual hair-relaxer lawsuits because Arizona is not suing over a particular woman’s cancer diagnosis. The state is pursuing a consumer-fraud theory centered on what L’Oréal allegedly knew, what it told customers and whether consumers received sufficient warnings.

Which L’Oréal Hair Relaxer Brands Are Involved?

The lawsuit concerns chemical hair relaxers sold through L’Oréal and its SoftSheen-Carson business. Allure reported that the products at issue include relaxers sold under brands such as Dark & Lovely, Optimum and Mizani. [Allure]

SoftSheen-Carson has long marketed hair-care products specifically toward Black consumers, making the racial demographics of relaxer use an important part of both the litigation and the public-health debate.

Arizona says some relaxer products were also promoted for use by children. [Arizona Attorney General]

What Chemicals Does Arizona Say Are A Problem?

Arizona alleges chemical relaxers can expose users to endocrine-disrupting chemicals and compounds associated with cancer risk. The attorney general specifically references categories including phthalates, parabens and other substances that may interfere with hormones or have been classified as known or probable carcinogens. [Arizona Attorney General]

Hair relaxers work by chemically breaking and reforming bonds that produce the natural curl structure of hair. The state argues that applying powerful alkaline products directly to the scalp can increase opportunities for chemical exposure. [Arizona Attorney General]

The presence of a potentially hazardous chemical does not by itself establish that a finished cosmetic product causes cancer at normal levels of use. That distinction is one of the central scientific issues disputed in the litigation.

What Did The NIH Study Find About Uterine Cancer?

A major 2022 National Institutes of Health study found an association between frequent use of chemical hair straighteners and uterine cancer. Researchers followed 33,497 women ages 35 to 74 for nearly 11 years and identified 378 uterine cancer cases. [NIH]

Women who reported using straightening products more than four times during the previous year were more than twice as likely to develop uterine cancer as women who reported no use. The published analysis calculated a hazard ratio of 2.55 for frequent users compared with nonusers. [Journal Of The National Cancer Institute]

Researchers estimated that approximately 1.64% of women who never used hair straighteners would develop uterine cancer by age 70, compared with approximately 4.05% of frequent users. [NIH]

Does That Mean Hair Relaxers Cause Uterine Cancer?

No study cited in the controversy proves by itself that a particular hair relaxer causes cancer. The 2022 NIH research found an epidemiological association, meaning uterine cancer occurred more frequently among women reporting straightener use after researchers adjusted for other factors. [NIH]

The researchers themselves said more research was necessary to confirm the findings in additional populations and determine which chemicals, if any, were responsible for the observed association. They also did not collect specific information about the brands or ingredients used by participants. [NIEHS]

That limitation is central to L’Oréal’s defense.

What Does L’Oréal Say About The Cancer Claims?

L’Oréal says its hair products are safe and argues that lawsuits attempting to connect its relaxers to cancer lack scientific and legal merit. The company says its products undergo scientific safety evaluations and must comply with applicable regulations. [L’Oréal]

L’Oréal specifically argues that the NIH study did not prove a causal relationship between its products and cancer and notes that the researchers themselves called for additional research. [L’Oréal]

The company says health and consumer safety are among its highest priorities and maintains that SoftSheen-Carson products are safe. [L’Oréal]

What Did Researchers Find About Ovarian Cancer?

Separate NIH-supported research has found an association between frequent hair-straightener use and ovarian cancer. The NIH Sister Study summarizes research finding that women who reported using straighteners or relaxers at least four times per year had approximately twice the ovarian cancer risk of women who did not use them. [NIH Sister Study]

As with the uterine-cancer findings, this research demonstrates an association rather than proving that relaxers directly caused individual cases.

Arizona cites ovarian cancer as one of the potential risks it says consumers should have been told about. [Arizona Attorney General]

What Did The Black Women’s Health Study Find?

A separate study focused specifically on Black women produced more nuanced findings. Researchers examining the Black Women’s Health Study found that long-term chemical hair-relaxer use was associated with higher uterine-cancer risk among postmenopausal women but not among premenopausal women. [PubMed]

Among postmenopausal women, moderate relaxer use was associated with a hazard ratio of 1.60 and heavy use with a hazard ratio of 1.64 compared with never or light use. Women reporting at least 20 years of use had a hazard ratio of 1.71. [PubMed]

The researchers concluded that long-term relaxer use could represent a modifiable uterine-cancer risk factor for postmenopausal women but emphasized that the evidence did not show the same result among premenopausal participants.

Have Hair Straighteners Been Linked To Breast Cancer?

Some studies have also reported associations between chemical straighteners and breast cancer. A 2019 NIH study involving 46,709 women found that women who used chemical straighteners at least every five to eight weeks had approximately a 30% higher breast-cancer risk than nonusers. [NIH]

Researchers cautioned that the result required replication and said it was too early to make a definitive recommendation based on that study alone. [NIH]

Earlier research has not always produced the same result. A previous Black Women’s Health Study analysis published in 2007 found no increase in breast-cancer incidence associated with hair-relaxer use. [PubMed]

That difference illustrates why scientists distinguish evidence of association from definitive proof of causation.

What About Thyroid And Pancreatic Cancer?

More recent research has expanded the questions beyond reproductive cancers. A study involving 46,287 participants in the NIH Sister Study found hair straightener and relaxer use was associated with higher incidences of thyroid and pancreatic cancers. [PubMed]

Researchers reported a hazard ratio of 1.71 for thyroid cancer and 2.66 for pancreatic cancer among users, although they found little evidence that risk consistently increased with greater frequency of use. [PubMed]

The study’s authors explicitly said additional research was needed to confirm those findings.

Arizona nevertheless references thyroid and pancreatic cancer among the hormonal or potentially related cancers discussed in its complaint. [Arizona Attorney General]

Why Are Black Women Central To The Hair Relaxer Lawsuits?

Chemical relaxer use has historically been much more prevalent among Black women than white women. In the 2022 NIH uterine-cancer study, approximately 60% of participants who reported using straighteners during the previous year identified as Black. [NIH]

Researchers did not find that the association between straightener use and uterine cancer was stronger because a woman was Black. Instead, they said the potential public-health impact could be greater for Black women because Black women are more likely to use relaxers and often begin using them at younger ages. [NIH]

Arizona makes the marketing of relaxers to Black women and girls an important part of its consumer-fraud allegations. [Arizona Attorney General]

Arizona Is The First State To File This Type Of Hair Relaxer Lawsuit

Reuters reported that Arizona’s case is the first state-level enforcement lawsuit accusing a hair-relaxer manufacturer of concealing cancer risks. Previously, the litigation had consisted primarily of lawsuits brought by individual consumers. [Reuters]

That distinction matters because a state attorney general can pursue alleged deceptive marketing practices affecting consumers broadly rather than having to prove that one specific plaintiff’s cancer was caused by one particular bottle of relaxer.

If Arizona succeeds with that theory, other state attorneys general could potentially examine similar claims under their own consumer-protection statutes.

More Than 12,000 Hair Relaxer Lawsuits Are Already Pending

The Arizona case arrives amid a much larger wave of private litigation. Reuters reported that more than 12,000 hair-relaxer lawsuits have been consolidated in federal court in Chicago. [Reuters]

The federal cases are organized as MDL No. 3060, formally titled In re: Hair Relaxer Marketing, Sales Practices, and Products Liability Litigation, in the U.S. District Court for the Northern District of Illinois. [U.S. District Court]

The Judicial Panel on Multidistrict Litigation created the consolidated proceeding in 2023 after finding that lawsuits around the country shared factual questions involving hair-relaxer marketing, ingredients and alleged cancer risks. [Federal Court Records]

L’Oréal is among several manufacturers named in those cases. Other companies have also faced hair-relaxer litigation.

Is Arizona Claiming Every Woman Who Used L’Oréal Relaxer Will Develop Cancer?

No. Neither Arizona’s case nor the scientific studies establish that every user will develop cancer.

Even the NIH study showing more than double the relative risk among frequent users estimated an absolute risk of approximately 4.05% for uterine cancer by age 70 compared with 1.64% among nonusers. [NIH]

That difference is scientifically meaningful, but it also means the large majority of women in both groups did not develop uterine cancer.

Cancer develops through many interacting factors, including age, genetics, hormones, lifestyle and environmental exposures. The litigation concerns whether chemical relaxers are one preventable contributor and whether manufacturers adequately disclosed what they knew about that potential risk.

Why The Arizona L’Oréal Lawsuit Matters

Arizona’s lawsuit shifts the hair-relaxer controversy from individual product-liability cases into government consumer-protection enforcement. The state does not need to prove at this stage that every L’Oréal relaxer caused a particular woman’s cancer. Its core accusation is that L’Oréal allegedly marketed products without appropriately disclosing significant emerging health-risk information.

L’Oréal’s defense is equally important: epidemiological studies can identify correlations without proving that a particular product or ingredient caused cancer, and the company says the existing evidence does not justify claims that its products are unsafe. [L’Oréal]

The legal fight will therefore revolve around two related but different questions: what the science actually establishes about cancer risk, and what L’Oréal knew or should have told consumers as that science developed.

With more than 12,000 private cases already consolidated in federal court and Arizona becoming the first state to bring its own enforcement action, the dispute over chemical hair relaxers has developed into one of the cosmetics industry’s largest current product-safety controversies. [Reuters]