Listerine Class Action Lawsuit Says Regular Use Can Increase Cancer-Causing Bacteria

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A proposed class action lawsuit alleges the makers of Listerine Cool Mint Antiseptic mouthwash have failed to warn consumers that regular use of the product as intended can spark the production of certain bacteria known to cause severe infections and closely linked to various types of cancer.

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The 35-page Listerine lawsuit against Johnson & Johnson Consumer, Inc. and Kenvue Inc. states that although the ubiquitous mouthwash is touted as able to “kill 99% of germs that cause bad breath, plaque & gingivitis,” among other claims, regular, intended use of the product can result in the proliferation of bacteria including, but not limited to, Streptococcus anginosus and Fusobacterium nucleatum. These and other bacteria are known to cause “severe invasive infections” and have been “closely associated” with oral cancer, head and neck cancer, colorectal cancer, esophageal cancer, breast cancer and others, the complaint states.

Though Kenvue specifically instructs consumers to use Listerine twice per day for 30 seconds, and warns that the product should not be swallowed or used by children under 12, the company has not disclosed, on product labels or elsewhere, that the mouthwash can increase the risk of dangerous cancers, the suit emphasizes.

According to the complaint, consumers “lost the entire benefit of their bargain” when they bought Listerine mouthwash that posed a serious, undisclosed health risk. The case says the Listerine Cool Mint mouthwash at issue is “in no way safe for humans” and “entirely worthless.”

“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 case charges.

Instead of warning consumers of the possible health risks of using Listerine, the defendants’ labeling “suggests the opposite,” the case contends. Per the suit, the warnings against swallowing and usage by children lead reasonable consumers to believe that the product is safe to use daily as directed.

However, a recent study found that Listerine, after three months of normal use, “greatly affected the microbiome composition, with Streptococcus anginosus and Fusobacterium nucleatum found to be “significantly more abundant” after that time period than at patients’ measured baseline, the lawsuit states.

“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.”

Streptococcus anginosus has been tied to gastrointestinal cancer and, more rarely, colorectal cancer, the suit adds.

Per the class action suit, the general consensus in published scientific literature is that the oral and gastrointestinal microbiomes play a major part in an array of cancers that are “established, promoted, and protected by imbalances of bacteria.”

The case claims the defendants have intentionally concealed from the public the dangers of using Listerine Cool Mint Antiseptic mouthwash. Under the Federal Food, Drug, and Cosmetics Act, Listerine is a misbranded and/or adulterated drug that “does not meet the general requirements for nonprescription drugs to be marketed without an approved [FDA] application.”

The Listerine class action lawsuit looks to cover all consumers in the United States who bought Listerine Cool Mint Antiseptic mouthwash for personal or household use within the applicable statute of limitations period.

How do I join the Listerine lawsuit?

When a class action lawsuit is initially filed, there’s usually nothing you need to do to join or sign up for the case. It’s typically in the event of a class action settlement that the people covered by a lawsuit, called class members, need to act. This usually involves filling out and filing a class action settlement claim form online or by mail.

ClassAction.org will update this page in the event of a Listerine settlement, so be sure to check back often.

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