The claim: Listerine can prevent and cure colds and sore throats; rinsing with it is as effective as flossing in fighting tooth and gum decay.
The truth: Initially sold as a surgical antiseptic in the 19th century, Listerine was the first product marketed as a mouthwash starting in 1914. In a landmark 1976 case, the FTC declared that the health claims were bogus and forced Warner-Lambert, its manufacturer at the time, to spend $10 million on ads that read, “Contrary to prior advertising, Listerine will not help prevent colds or sore throats or lessen their severity.” More recently, in 2005, a federal judge ordered Pfizer, then maker of Listerine, to pull its commercials claiming that rinsing with Listerine is as effective as flossing in fighting tooth and gum decay.