Warnings against addictive products inform the public about potential health and behavioral risks caused by the use and abuse of such products, in order to minimize such risks. This paper analyzes the aspects of information processing, emotional responses, and possible changes of attitude due to variations in two important conditions for such communications: the threat in the message contents and the nature of the issuer. To do so, this paper offers a conceptual review of diverse aspects that affect the efficacy of the warnings, it examines the persuasive role of the threat in the communication and of the issuer of the message and, finally, it discusses the weight of some personal variables that affect information processing. Such arguments give rise to a set of propositions for research on the cognitive process of interiorization that such messages have and on how a person’s attitude may be affected. The conceptual basis for this paper is a combination of the elaboration likelihood model (ELM) and of the protection motivation theory (PMT).