Major Defendants Kept in 12,000-Case Hair Relaxer Cancer Lawsuit as Arizona Files State Claim

More than 12,129 individual lawsuits have now been filed against major cosmetics manufacturers over chemical hair relaxers, a volume of litigation that represents one of the largest active mass torts in the United States. That federal multidistrict litigation will now proceed toward trial, after U.S. District Judge Mary M. Rowland denied the defendants' motions to dismiss the core claims. The ruling keeps industry giants like L'Oréal and Revlon on the hook for allegations that their hair-straightening products cause uterine and ovarian cancer. As the federal cases advance in Chicago, the legal battle has also expanded to the state level, with Arizona becoming the first state to sue L'Oréal for consumer fraud.[4][5]

Arizona Attorney General Kris Mayes filed the state's 25-page lawsuit in Maricopa County on September 10, 2026, targeting L'Oréal USA and SoftSheen-Carson. Unlike the federal cases—which focus on personal injury claims from women who developed cancer—Arizona's lawsuit centers on deceptive marketing. The state alleges that the companies knew about the potential carcinogenic risks of products like Dark and Lovely and Optimum, but concealed that information from consumers to protect a $718 million industry. "Instead of warning their consumers, they put profits over the safety of women and children," Mayes said in a statement. "That is unacceptable and we will hold them accountable for it."[1][2][4]

The foundation for both the federal and state lawsuits rests heavily on a 2022 study published by the National Institutes of Health. That research tracked more than 33,000 women and found that those who used chemical hair straighteners more than four times a year were more than twice as likely to develop uterine cancer compared to non-users. The products rely on alkaline and hydroxide-based formulas to break down the proteins that give hair its shape, and plaintiffs argue these formulas contain endocrine-disrupting chemicals that absorb into the scalp.[4][5]

L'Oréal has consistently disputed the allegations across all jurisdictions. A spokesperson for the company stated that its products undergo rigorous safety reviews and that the claims lack both legal and scientific merit. The company argues that the 2022 NIH study did not establish a definitive causal connection between the use of its specific products and the cancers alleged by the plaintiffs.[3][4][5]

Despite those defenses, Judge Rowland's recent rulings in the federal multidistrict litigation have cleared the path for discovery and bellwether trials. The court rejected the defendants' arguments that federal law preempted the state-level product liability claims, allowing allegations of negligence, design defect, and failure to warn to survive. The judge also permitted claims for economic losses and medical monitoring costs to proceed, ensuring that consumers who have not yet developed cancer but require ongoing screening can remain part of the litigation.[4]

Arizona's entry into the fray introduces a new layer of financial exposure for the cosmetics industry. The state is seeking civil penalties of up to $10,000 for each willful violation of the Arizona Consumer Fraud Act, arguing that every individual sale or misleading advertisement could constitute a separate offense. Furthermore, the state is asking the court to mandate explicit cancer warning labels on the products, which are still sold on store shelves today.[4][5]

The marketing of these products has also become a central issue in the legal arguments. Arizona's complaint contends that L'Oréal perpetuated "Eurocentric beauty standards" since the 1970s, aggressively marketing chemical relaxers to Black and Brown women and children while prioritizing profits over safety. Plaintiffs in the federal cases have echoed similar arguments, pointing to the disproportionate impact the products have had on women of African descent.[1][4][5]

With the motions to dismiss denied, the federal litigation is now moving into a critical evidentiary phase. The court has scheduled a dedicated science hearing and set firm deadlines for expert discovery, where both sides will debate the epidemiological data linking relaxer chemicals to hormone-sensitive cancers. The first bellwether test trials are currently scheduled for September 2027. Those initial verdicts will determine how juries weigh the scientific evidence and establish the financial baseline for any potential global settlement across the 12,000 pending claims.[4][5]