The makers of the Airborne dietary supplement have agreed to pay as much as $30 million to consumers to settle Federal Trade Commission charges that its makers made false and unsubstantiated cold prevention claims.

“There is no credible evidence that Airborne products, taken as directed, will reduce the severity or duration of colds, or provide any tangible benefit for people who are exposed to germs in crowded places,” said Lydia Parnes, Director of the FTC’s Bureau of Consumer Protection in a release.

In its complaint, the FTC cites Airborne advertisements in which speakers claimed the supplement cured their cold in an hour, was a “miracle cold buster,” and was created by a teacher who “was sick of catching colds in class.”

The supplement, which contains 17 herbs and nutrients, was widely sold by major retailers such as Wal-Mart, CVS, Walgreens and Costco; and was marketed on daytime television programming, and through magazines and celebrity endorsements.

Airborne’s label urges users to take the supplement at the first sign of a cold and before entering crowded situations. The label depicts a picture of someone sneezing into their handkerchief.

The FTC charged that the makers of Airborne, former teacher Victoria Knight-McDowell and her husband, made express or implied unsubstantiated claims that the product could reduce the risk of or prevent colds, protect against or help fight germs, reduce the severity or duration of a cold, and protect against colds, sickness and infection in crowded places.

The FTC’s complaint and agreed-upon settlement follows a class-action lawsuit, pending in the U.S. District Court for the Central District of California. The defendants already agreed in that case to pay $23.5 million for consumer refunds. To settle the follow-on FTC action, the defendants agreed to pay an additional $6.5 million in funds for consumer redress if needed to settle consumer claims.

Nonetheless, Airborne is hardly in retreat.

In a feisty release, the company vigorously denied any wrongdoing or illegal conduct in both the class and FTC actions. The settlement involves older advertising, the company noted, but it stood behind its product’s efficacy.

“Consumers can feel confident that the advertising and labeling going into the marketplace accurately reflects what Airborne products do,” said Airborne CEO Elise Donahue. “Our products help support the immune system. In fact the key ingredients in Airborne have been studied in scientific research and reported in medical journals. Airborne is the same product that millions of consumers swear by. Airborne, meanwhile, continues to be the #1-selling immune support dietary supplement, and we’re very proud of this fact.”

Why This Matters:  There is no known cure for the common cold, and any claims to the contrary are likely to catch the attention of regulators—or plaintiffs’ attorneys.