Consumer Perceptions Influence Supplement Choice: A Narrative Review of Clinically Studied Weight-Management Supplements in Obesity

Obesity is a major public health problem with a continuously increasing global prevalence and is associated with various chronic diseases and substantial social and economic burdens. As dietary modification and physical activity alone often have limited effectiveness in achieving sustained weight loss, dietary supplements intended for weight reduction are widely used. However, evidence on the efficacy and safety of these supplements is inconsistent, and consumer use intentions tend to be driven by subjective beliefs and insurance-like perceptions. Accordingly, this study reviewed recent evidence on L-carnitine, green tea extract, glucomannan, and Garcinia cambogia, supplements for which weight loss effects have been proposed, to assess their efficacy and safety and to highlight the importance of supplement selection aligned with consumer use contexts. PubMed, MEDLINE, and Google Scholar databases were searched for studies published between 1 January 2020 and 10 October 2025. Although some studies have reported improvements in weight and metabolic indicators, consistent scientific evidence has not yet been established. This review emphasized the need for purpose-driven supplement selection that integrates efficacy, safety, usage context, and evidence level, and the importance of consumers’ critical information appraisal capacity, supported by structured information provision and education.