Ethicisation refers to the tendency to frame issues in ethical terms and can be observed in different areas of society, particularly in relation to policy-making on emerging technologies. The turn to ethics implies increased use of ethics expertise, or at least an expectation that this is the case. Calling for experts on ethics when ethically complicated questions need to be handled helps us to uphold central virtues, but there are also problems connected with ethicisation. In policy-making processes, the turn to ethics may not always be a sign of a sincere aspiration to moral performance, but a strategic move to gain acceptance for controversial or sensitive activities, and ethicisation may depoliticise questions and constrain room for democratic participation. Nevertheless, ethicisation, and the ensuing call for ethics experts, suggests an expectation of confidence in ethics and ethics expertise, and that ethical guidance is an effective way of governing people’s behaviour in a morally desirable way. The purpose of this article is to explore democratic and epistemic challenges of ethicisation in the context of emerging technologies, with a specific focus on how the notions of under-reliance and over-reliance of ethics expertise can unpack the processes at play. By using biotechnology and the EU process of bio-patents and the publication of ethical guidelines for AI development as illustrations, it is demonstrated how ethicisation may give rise to democratic and epistemic challenges that are not explicitly addressed in discussions on the political use of ethics expertise.