Abstract: This study examined the mechanisms through which attitudes toward OTCA in general and OTCA prompted behaviors are formed based on a consumer socialization framework. An online survey was conducted using the Qualtrics online panel. Completed questionnaires were received from 539 individuals who had taken prescription medicine in the last six months. Of those, 304 were from U.S. adults who had taken an OTC medicine and had seen an advertisement for OTC medicines in the past six months were analyzed to test the proposed model. The results showed that consumers’ use of mass media and professional interpersonal channels directly influenced OTCA attitudes and prompted behaviors. On the other hand, consumers’ use of non-professional interpersonal channels indirectly influenced OTCA outcomes through their use of mass media and professional interpersonal channels. Younger respondents were more likely to obtain OTC medicine information from non-professional interpersonal and mass media sources whereas older respondents were more likely to obtain OTC medicine information from physicians and pharmacists. The findings of this study provide implications for pharmaceutical marketers, health professionals, and consumers of OTC medicines.