Consumer Decision-Making in Supplementation: A Systematic Review Using the Health Belief Model

The growing consumer interest in preventive health and wellness products has intensified the importance of understanding the psychological and behavioural factors influencing consumer decision-making in supplementation. This study systematically reviews existing research on dietary and health supplement consumption through the lens of the Health Belief Model (HBM), with a specific focus on its relevance to consumer decision-making. The systematic review followed PRISMA guidelines. Database searches of Scopus and PubMed (2014-2024) identified 407 articles, of which 21 met the inclusion criteria and were narratively synthesized. The findings indicate that supplementation behaviour is best understood as a value–risk evaluation process, in which consumers assess perceived benefits against perceived barriers under varying levels of perceived risk and behavioural capability. Perceived benefits emerge as the most dominant driver, suggesting that consumers approach supplementation as a value-seeking behaviour rather than purely a risk-avoidance response. In contrast, perceived barriers such as cost, accessibility, and uncertainty act as key inhibitors, reinforcing cost–benefit trade-offs in decision-making. Constructs such as perceived susceptibility and severity demonstrate context-specific effects, while self-efficacy and cues to action facilitate the translation of intention into behaviour. The study conceptualizes supplementation as a multi-stage consumer decision process involving risk perception, value evaluation, and behavioural execution, and highlights the enhanced explanatory power of integrating HBM with the Theory of Planned Behavior. The findings offer important implications for marketers and identify key directions for future research in preventive health consumption.