European Health Data Space Regulation: Users' Free Choice or Maximum Harmonisation?

The European Health Data Space (EHDS) Regulation establishes a governance framework for secondary health data use, yet its material scope remains contested. A dichotomy has emerged between 'dualists', who interpret Article 1(8) as granting health data users a permanent choice between the EHDS and national regimes, and 'monists', who view the Regulation as exhaustive maximum harmonisation. This research collects and groups the arguments supporting the two interpretations, in line with the textual, systemic, and teleological methods of the EU Court of Justice. As a result, the article analyses legislative evolution, the implications of the introduced 'permit power', and the effet utile of the Regulation. While legal ambiguity persists pending CJEU clarification, the article recommends pragmatic implementation strategies to prevent administrative bottlenecks and ensure future-proof compliance.