Effects of misleading online advertisements on the purchase intention of mature Chinese consumers for dietary supplements

Purpose Advertisements for dietary supplements (DS) often include misleading claims regarding their health benefits. In this study, the authors designed an online advertisement for plant-based DS featuring misleading claims and investigated its effects on mature Chinese consumers before and after revealing the false claims. A consumer involvement framework was developed to evaluate the mediating effect of advertising involvement (AI) on the correlation between product involvement (PI), situational involvement (SI) and purchase intention (PI). Design/methodology/approach A total of 467 mature adults aged over 40 years who resided in China's Yangtze River Delta region and had experience in purchasing DS online were recruited. Relevant data were collected through an online survey and analysed through structural equation modelling. Findings Cognitive PI was positively correlated with both SI and PI and SI was positively correlated with PI. AI negatively moderated the correlation between affective PI and SI. Both cognitive PI and AI were positively correlated with PI and the correlation was mediated through SI. Originality/value DS consumption is a rational decision-making process driven by utilitarian motives. Consumers who are aware of the misleading claims adopt a cautious evaluation approach and place themselves in specific purchase situations before making a purchase decision. This study advances the literature by incorporating the consideration of misleading advertisements into the consumer involvement model within the context of online DS consumption. The study's findings provide insights to intensify monitoring of false advertisements in the DS industry and design effective consumer education programmes.