Human enhancement products allow consumers to radically enhance their mental abilities. Focusing on cognitive enhancements, we introduce and study a novel factor dehumanization (i.e., denying a person emotional ability and likening them to a robot) which plays a key role in consumers' reluctance to use enhancement products. In study 1, consumers who enhance their mental abilities beyond normal levels were dehumanized, whereas consumers who use the same products to restore lost abilities were not. Moreover, dehumanization decreased prospective consumers' interest in using the enhancement products themselves. Study 2 shows that emphasizing how the motivation to use an enhancement product can be prosocial (i.e., helping other people) inoculates the consumer against dehumanization, and study 3 supports this positioning strategy in an online advertising campaign. Together, these studies uncover dehumanization as an important obstacle to consumer adoption of enhancement products and demonstrate how to overcome this obstacle with a prosocial positioning strategy.