Listerine Class Action: Does Mouthwash Increase Cancer Risk?

Case Overview: A class action lawsuit has been filed against Johnson & Johnson and Kenvue, alleging that Listerine mouthwash can promote the growth of cancer-causing bacteria and that the companies failed to warn consumers.

Consumers Affected: Individuals who purchased and used Listerine Cool Mint Antiseptic mouthwash.

Court: U.S. District Court for the Central District of California

Johnson & Johnson Consumer, Inc. and Kenvue Inc., the makers of Listerine Cool Mint Antiseptic mouthwash, are facing a class action lawsuit alleging that they failed to warn consumers about a potential link between regular Listerine use and the growth of cancer-causing bacteria.

Filed by Paige Vasseur in a California federal court, the lawsuit claims that while Listerine is marketed as a product that kills harmful germs, its regular use can actually lead to the proliferation of certain bacteria associated with various types of cancer.

Vasseur contends that Johnson & Johnson and Kenvue were aware of this potential risk but did not disclose it to consumers. She argues that the companies' marketing and labeling of Listerine are deceptive because they fail to warn of this potential health risk.

Listerine Use Linked to Cancer-Causing Bacteria, Lawsuit Claims

Listerine is widely advertised as a mouthwash that "kills 99% of germs that cause bad breath, plaque & gingivitis." However, the class action alleges that regular use of Listerine as directed can lead to the growth of bacteria such as Streptococcus anginosus and Fusobacterium nucleatum. These bacteria have been linked to severe infections and various types of cancer, including oral, head and neck, colorectal, esophageal, and breast cancer.

Vasseur claims that the companies' instructions to use Listerine twice daily for 30 seconds, along with the warnings against swallowing and use by children under 12, mislead consumers into believing that the product is safe for daily use as directed. She argues that the absence of any warnings about the potential link to cancer-causing bacteria is deceptive and misleading.

“Unfortunately for consumers, Defendants’ advertising and marketing campaign is false, deceptive, and misleading because nowhere on the Product’s packaging or labeling do Defendants disclose that the Product leads to the proliferation of cancer-causing bacteria,” the lawsuit states.

Study Finds Listerine Can Disrupt Oral Microbiome, Increase Cancer Risk

A recent study published in the Journal of Medical Microbiology found that Listerine use, after three months of normal use, "greatly affected the microbiome composition." The study found that Streptococcus anginosus and Fusobacterium nucleatum were "significantly more abundant" after Listerine use compared to baseline measurements.

Fusobacterium nucleatum has been closely associated with various cancers, including oral, head and neck, colorectal, pancreatic, esophageal, and breast cancer. Streptococcus anginosus has also been linked to gastrointestinal and colorectal cancers.

The class action emphasizes the role of the oral and gastrointestinal microbiomes in the development of various cancers and argues that imbalances in these microbiomes, potentially caused by Listerine use, can contribute to cancer risk.

“Fusobacterium nucleatum is a bacteria that is closely associated with oral cancer, head & neck cancer, colorectal cancer, pancreatic cancer, esophageal cancer, and breast cancer. Studies have been conducted that closely link this particular bacteria with colorectal cancers, but also link oral concentration of this bacteria with prediction of colon cancer prognosis. Additionally, these bacteria have been shown to survive longer than other bacteria under acidic conditions, like those found in the gut, which suggests that they may travel from the mouth to the gut through the digestive tract,” the complaint says.

Lawsuit Seeks to Hold Listerine Manufacturers Accountable for Misleading Consumers

The case claims that Listerine, under the Federal Food, Drug, and Cosmetics Act, is a misbranded and/or adulterated drug because it does not meet the general requirements for nonprescription drugs to be marketed without an approved FDA application. It argues that the companies' failure to disclose the potential risk of cancer-causing bacteria renders Listerine misbranded and unsafe for human use.

In the Listerine class action lawsuit, Vasseur seeks to represent all consumers in the United States who purchased Listerine Cool Mint Antiseptic mouthwash for personal or household use within the applicable statute of limitations period.

She is seeking various forms of relief, including a declaration that Listerine is misbranded and unsafe; an injunction prohibiting the companies from continuing their allegedly deceptive marketing and labeling practices; restitution and damages to compensate consumers for their losses; and corrective advertising to inform the public about the potential risks associated with Listerine use.

Case Details

• Lawsuit: Vasseur v. Johnson & Johnson Consumer, Inc., et al.
• Case Number: 2:24-cv-07487 
• Court: U.S. District Court for the Central District of California 

Plaintiffs' Attorneys

• Trenton R. Kashima (Milberg Coleman bryson Phillips Grossman PLLC)
• Jonathan Shub (Shub & Johns LLC)

Have you used Listerine Cool Mint Antiseptic mouthwash? Share your experiences and thoughts in the comments below.