Arguments grounded on separation of powers and contextual expertise suggest that courts should refrain from undertaking searching inquiries into complex factual backgrounds. Measures that are the result of expert-intensive decision making have therefore traditionally been subject to a light-touch judicial review by the European Courts. Interestingly, things may be changing, as the CJEU has been developing a more proactive approach to the review of expert-based measures, especially in the field of risk regulation. The paper will undertake a cross-sectoral judicial analysis to try and understand how the CJEU frames and applies principles, such as participation, transparency and rational administrative decision making, when reviewing expert-based measures. In so doing, it will explore the hypothesis according to which judicial interpretation of such principles can act as a trigger for more legitimate and democratically sound involvement of experts in EU regulatory decision making.