Published Articles

January 16th, 2005

Do You Have Proof for Your Claims? And Do You Floss?

Like many Americans, I have had some awkward conversations with my dental hygienist trying to explain why I hadn’t flossed. So when I saw Listerine’s recent advertising campaign promoting mouthwash that is "as effective as floss," I put aside the jaded skepticism of an advertising lawyer and rushed out to buy a bottle of Cool Mint Listerine. As I left for the office the next morning, I thought, not only will I have fresh breath, but never again will I have to feel guilty about not flossing.

Listerine launched its "as effective as floss" consumer advertising campaign in June 2004. One television commercial claimed that "Listerine’s as effective as floss at fighting plaque and gingivitis. Clinical studies prove it." Almost like liquid floss, the commercial also showed a stream of blue liquid swirling around and between teeth. The spot does warn, however, that "there’s no replacement for flossing."

Last fall, McNeil-PPC, Inc., the market leader in dental floss sales, sued Pfizer Inc., the maker of Listerine, alleging that Pfizer’s advertising was false and misleading. McNeil argued that Pfizer was falsely claiming that clinical studies showed that Listerine is as effective as floss against plaque and gingivitis and that Listerine can serve as a replacement for floss. Earlier this month, a federal court in New York found that McNeil was likely to win the lawsuit and granted McNeil a preliminary injunction barring Pfizer from making these claims, at least until the lawsuit is concluded.

Lessons from Listerine?

The effect of the preliminary injunction will be dramatic. While the lawsuit is pending, McNeil will have to pull advertising, which will include putting a sticker over affected Listerine labels. If you want to avoid being forced to scrap your advertising campaign, there are some important lessons to be learned.

Even though Listerine’s advertising did not mention any of McNeil’s products by name, McNeil still sued. Competitors can sue you for false advertising, even if you don’t mention them or their products.

If you claim in a commercial that "studies prove" something, you must actually have the studies that you say you have. In the Listerine case, the court found that Pfizer’s claim that "Listerine is as effective as floss against plaque and gingivitis" was overly broad, since the studies only tested people with mild to moderate gingivitis – not people with severe gingivitis or periodontitis. When citing a clinical study in your advertising, you also have to ensure that the study is sufficiently reliable. Here, the court found that the studies didn’t prove that Listerine is "as effective as floss," but only proved that Listerine is as effective as floss when flossing is not done properly.

When illustrating the performance of a product – even in a fanciful way – you may be held responsible for any unintended claims that are communicated. For example, the court found that, by showing a stream of a blue liquid tracking floss as it is removed from the floss container and then showing the mouthwash swirling between and around teeth, Pfizer had implied that Listerine is a replacement for floss.

If you’re worried that someone may be confused by your ad, disclaimers may not solve your problem. Although Pfizer included disclaimers such as "floss daily" and "there’s no replacement for flossing," the court found that the disclaimers didn’t adequately correct any misimpression when the ads were considered as a whole.

If you want to avoid trouble with your advertising, make sure you have proper substantiation for your claims. And if you want to avoid trouble with your teeth (at least until we see more research), it seems like you’d better floss.

- Jeffrey A. Greenbaum

This article first appeared in the January 2005 issue of SHOOT magazine. It presents a general discussion of legal issues, but is not legal advice, and may not be applicable in all situations. Consult your attorney for legal advice.