Self-care, advocated by the WHO, promotes the use of over-the-counter (OTC) medications for self-medication particularly in regions like Indonesia with inadequate healthcare infrastructure. Fierce competition in the OTC drug category arises due to numerous companies and similar products, driven by limited patent durations and strict regulations. This study investigates the high involvement nature of the OTC drug category, where consumers rely on trust and knowledge in brand selection, influenced by pharmacist recommendation, word of mouth (WOM), brand popularity, and perceived effectiveness.

Conducted in the Jabodetabek area with 230 respondents, data analysis utilized SEM-PLS. Findings revealed WOM's positive impact on brand popularity and perceived effectiveness, which subsequently influenced attitude toward the brand with trust as mediating variable. Interestingly, pharmacist recommendation, despite its significance in other contexts, did not affect attitude toward the brand in this study.

Marketing strategies should focus on increasing product awareness through effective information dissemination, leveraging both traditional and digital channels. Moreover, cultivating community opinions is crucial, as WOM plays a pivotal role in enhancing brand popularity and perceived effectiveness. These insights underscore the importance of tailored marketing strategies in promoting OTC drugs effectively and improving public health standards swiftly