A differentiation of research-based data protection regimes is proposed in light of the distinction between merely for profit and public interest-oriented research. This would support a differentiated level of data subjects’ control prerogatives and data controllers’ mobilization ease. The article demonstrates how the existence of differential data protection regimes in EU data protection law has a corresponding differentiated impact enabling data sharing practices of personal data and in particular of special categories of data. Differentiated data protection regimes impact differently on contractual freedom to share and aggregate personal data, which is the primary pillar of the creation of “common data spaces” under the latest European strategy for data and under the Data Governance Act.