Ad description
A TV ad for Listerine mouthwash shown on 28 January 2025 depicted a woman in a bathroom facing a mirror about to floss her teeth. An animated donkey appeared behind her in the bath, pulling back the shower curtain. The donkey said, “Good on you. Flossing helps but why not add Listerine.” A picture of the product was then shown and the donkey and on-screen text stated, “PROVEN TO BE 5X MORE EFFECTIVE THAN FLOSS AT REDUCING PLAQUE*”. Superimposed text stated. “*Germ kill provides sustained plaque reduction above the gumline after a dental cleaning”. The woman was then shown gargling mouthwash. Then an animated image of the inside of a person’s mouth was displayed. Mouthwash was shown entering the mouth through the teeth and removing bacteria which were represented by green particles. The voiceover continued, “Listerine gets into the nooks. Into the crannies. Fight the good fight with a swish and a zing.” The woman was then shown with the mouthwash in her mouth, visibly surprised, as her cheeks expanded. Superimposed text stated, “Complete your routine – use alongside brushing and flossing”. The voiceover continued, “When you are taking on plaque, add Listerine.” The donkey appeared behind an image of the product. Superimposed text stated, “PROVEN TO BE 5X MORE EFFECTIVE THAN FLOSS AT REDUCING PLAQUE*”. Qualifying text said, “Complete your routine – use alongside brushing and flossing”.
Issue
The complainants, who believed the ad suggested mouthwash as an alternative to flossing was five times more effective, challenged whether the ad was misleading.
Response
Kenvue UK Ltd t/a Listerine said the claim “proven to be 5x more effective than floss at reducing plaque”, which was supported by two published studies, was qualified with text that stated, “*Germ kill provides sustained plaque reduction above the gumline after a dental cleaning”.
Therefore, it indicated to the viewer that the effect was on the teeth above the gumline and the ad as a whole would have been seen in that context. In contrast, floss or interdental brushes were recommended between the teeth to clean below the gumline before brushing. They said the ad did not suggest the product had an effect below the gumline and so did not suggest the product should replace floss, but encouraged people to use mouthwash alongside brushing and flossing. They explained further that tooth decay was one of the most common non-contagious diseases in the United Kingdom. It was therefore a contributing factor as to why the ad focused on germ kill and subsequent plaque reduction above the gumline.
They said use of floss was also encouraged in the opening frame of the ad where the woman was shown flossing and the voiceover said, “Good on you, flossing helps but why not add Listerine?”. The ad therefore praised the woman for using floss, confirmed flossing was useful and encouraged viewers to add Listerine to their oral health routine. After that a bottle of Listerine was also shown side by side with dental floss, which was clearly labelled, reinforcing the idea that the two products should be complementary. Later on in the ad, superimposed text stated, “Complete your routine – use alongside brushing and flossing”, which they believed was prominent and held long enough for viewers to read, and the final voiceover said, “When you are taking on plaque, add Listerine”. Both again reiterated the message that Listerine should be added as part of an oral health routine, rather than replacing flossing or brushing. They said therefore multiple references were made to flossing and using Listerine alongside flossing and brushing in the 20 seconds the ad ran for, and for that reason the ad did not exaggerate the capability or performance of Listerine.
They further stated that the animation of the mouth and Listerine filtering through the teeth demonstrated how mouthwash, due to it being a liquid, could reach all surfaces, including between the teeth. It further demonstrated the anti-bacterial effect of Listerine, which was proven to be 99.9%. The animation did not show food particles being dislodged from the teeth but instead showed bacteria being destroyed from the surface of the teeth and gums. They said that was clear from the green colour and spherical or rod-shaped forms, often associated with bacteria, that would not be mistaken for food or plaque, which was a film. That was especially the case because the qualifying text “*Germ kill provides sustained plaque reduction above the gumline after a dental cleaning” appeared for the duration of the scene. They also explained that the animation clearly showed the mouthwash reaching all the surfaces in the oral cavity. It would therefore not be seen as acting in the same way as floss which was used between the teeth and below the gumline.
They stated that overall, the primary message of the ad was to highlight the effectiveness of Listerine in reducing plaque above the gumline. To provide context as to the extent of that benefit, a comparison versus flossing was provided. That was a specific benefit that complemented, rather than replaced, the use of dental floss. The ad emphasised the additional benefit of using Listerine as part of a comprehensive oral health routine, which included brushing and flossing. That would be understood by watching the ad in its entirety and considering it overall, rather than in isolated frames or sections.
They confirmed the ad was no longer being broadcast.
Clearcast said the ad, including the voiceover, made it clear that Listerine should be used as part of a routine that also included brushing and flossing and that the benefits of all three went together. Therefore, the ad did not state that dental floss should not be used and instead showed it as an important part of teeth cleaning. That was supported by wording of the ad that stated, “Flossing helps but why not add Listerine”, “complete your routine – use alongside brushing and flossing” and “when you’re taking on plaque add Listerine”. In addition, the shot of the product said “use alongside brushing and flossing”.
Clearcast said they were happy with the visual representation of plaque removal in the ad, which was not shown as being below the gumline. They explained that the ad made clear that Listerine was to be used after both brushing and flossing, meaning plaque on and between the teeth had already been tackled. In addition, the ad included the claim “plaque reduction above the gumline” and at the beginning of the ad the actor was shown putting the dental floss down, therefore indicating plaque reduction below the gum line had already been completed.
They said their consultant had reviewed the evidence and was satisfied that the claim “proven to be 5x more effective than floss at reducing plaque” had been substantiated. In addition, the consultant and Listerine noted that the evidence actually showed that Listerine was nine times more effective than flossing at removing plaque and so the ad underclaimed and did not exaggerate the benefit of the product. Their consultant had said that as long as the mouthwash had been used as directed in the ad, it would access all parts of the mouth and exposed teeth surfaces.
Assessment
Upheld
The BCAP Code stated ads must not materially mislead or be likely to do so and must not mislead by exaggerating the capability or performance of a product or service.
The ASA acknowledged Listerine’s comments that the ad made frequent references to the product complementing floss, rather than replacing it, either in the voiceover or the visuals of the ad. However, some of those examples, such as the woman shown flossing and the floss shown side by side with Listerine, were fleeting, or in the case of the bottle of Listerine stating ”use alongside brushing and flossing” not clearly legible, and therefore they could have been easily missed by viewers. Other examples, such as when the voiceover stated, “… flossing helps but why not add Listerine?”, “When you are taking on plaque, add Listerine” and the on-screen text “… use alongside brushing and flossing”, were clearer. However, we noted that primary prominence was given to the claim “PROVEN TO BE 5X MORE EFFECTIVE THAN FLOSS AT REDUCING PLAQUE” in terms of the size of the text, as well as appearing in the voiceover. Therefore, we considered that the focus of the ad was on Listerine being five times more effective than floss in removing plaque and was likely to be understood by viewers as a substitute for floss, rather than as complementary.
We considered the claim “PROVEN TO BE 5X MORE EFFECTIVE THAN FLOSS AT REDUCING PLAQUE” was likely to be understood in isolation to relate to plaque removal in general. However, we understood the comparison was intended to relate to the removal of plaque only above the gumline. We understood rinsing primarily acted on the surface of the mouth, although some data indicated it had an antibacterial effect below the gums, and killed bacteria that could cause plaque to develop, but did not remove plaque. In contrast, flossing was used to dislodge food particles and also manually remove plaque both below and above the gumline. We considered the qualifying text, “*Germ kill provides sustained plaque reduction above the gumline after a dental cleaning”, was relatively small compared to the headline claim and therefore easily missed or overlooked in contrast to the headline claim. In addition, we considered the wording of the qualification, referencing “Germ kill … after a dental cleaning” did not make it clear that the claim was based on plaque reduction above the gumline using Listerine after brushing versus floss when used alone with brushing. We therefore considered the qualification was insufficient to clarify the impression given by the “5X MORE EFFECTIVE” claim.
The animation of Listerine entering the mouth and removing green particles was another prominent part of the ad. It showed Listerine cascading through the teeth and the voiceover stated, “Listerine gets into the nooks. Into the crannies”. We understood the green particles represented bacteria but considered the ad did not make that clear and that they could have been mistaken for plaque or food. We considered, in the context of the claim “PROVEN TO BE 5X MORE EFFECTIVE THAN FLOSS AT REDUCING PLAQUE”, the scene was likely to be understood as suggesting mouthwash acted in the same way as floss, and so was a five times more effective replacement, rather than as relating to complementary plaque removal above the gumline.
We considered the ad was ambiguous, but that it was overall likely to be seen as presenting rinsing with Listerine as a superior replacement for flossing. Because we understood that was not the case, we concluded that it misleadingly exaggerated the product’s performance and therefore breached the Code.
The ad breached BCAP rules 3.1 (Misleadingness), 3.10 (Qualification) and 3.12 (Exaggeration).
Action
The ad must not be broadcast again in the form complained of. We told Kenvue UK Ltd t/a Listerine to ensure future ads did not mislead by exaggerating the capability or performance of a product.
