This paper focuses on the problematic consequences related to the introduction of an advisory opinions procedure to the European Court of Human Rights as outlined by Protocol No. 16 to the European Convention on Human Rights. In particular, moving from the characteristics and the rationale underlying this new procedural mechanism of judicial protection, its possible interferences with other judicial instruments of rights protection involving national judges at the supranational (EU) and national level are examined, namely those with the reference for a preliminary ruling to the Court of Justice of the European Union, and the constitutional review of legislation (the incidental control of constitutionality in the Italian system of Constitutional Justice is taken into account). In this framework, examining the critical issues potentially arising from this innovation in view of the current balance concerning the three systems considered (national, supranational and regional international), the analysis seeks to answer the question of whether the latter may increase or, conversely, decrease an “overall” effectiveness of protection.