Over-the-counter (OTC) products are widely available healthcare products that consumers use without prescriptions. These products, along with nutritional supplements and consumer healthcare devices, are part of consumer healthcare products. This research aims to expand the literature by assessing the effects of promotional activities on consumers’ purchase intention and brand loyalty for OTC products. It also seeks to provide the pharmaceutical industry with a data-driven source for the ethical promotion of OTC products to enhance consumer satisfaction and trust. Although promotional activities significantly influence consumer decisions, their effectiveness varies due to regulatory differences across countries. This study investigates the impact of promotional activities on consumers’ purchase intention and brand loyalty, focusing on the mediating role of brand image in Turkey. Data were collected from 668 adult OTC consumers using purposive sampling and analyzed through structural equation modeling (SmartPLS). Results demonstrate that promotional activities positively affect purchase intention and brand loyalty, with brand image significantly mediating. These findings extend pharmaceutical marketing literature and provide practical insights for developing ethical and effective integrated marketing communication strategies in the OTC market.