This study explores the neuropsychological effect of how a customer becomes trustworthy for a brand. The study investigates human neuropsychology and various components of the brain and its chemicals that play a behaviour-generating and behaviour-driving role in making a brand successful or fail in the market. Digging into the psychological sphere, the study explores and finds out how the consumer’s brain reacts when it experiences the right product and the right communication and service. The results establish how effective and creative marketing moves secrete favorable brain chemicals like serotonin and oxytocin and how these chemicals have a significant positive influence on the satisfaction of consumers’ basic needs, and the perceived value of the products. The study further demonstrates how trust-building chemicals like serotonin and oxytocin contribute significantly to consumers’ anticipation and excitement and how the surge of the chemicals results in positive emotion. The findings expand the literature by providing a better understanding of the core mechanisms of the brain. The study applies the conceptual framework and the mode of research is qualitative research, but it also takes into account quantitative data. It figures out the complex link between the secretions of brain chemicals and consumers’ buying behaviour. I use and build hypotheses based on secondary data about perceived quality, brand awareness, brand association and brand loyalty.