Informed consent, as an expression of self-determination, forms an elementary shield against foreign domination and exploitation. That is why it has become the central condition for the admissibility of medical research involving human beings for all subjects protection systems. But are these subjects protection systems compatible with the idea of informed consent, if it is essential to conduct research with subjects, who may not or can not decide for themselves? How does this comply with the right of these persons to self-determination? This book seeks to answer these questions, in particular through the analysis of the relation between the legally required consent for the participation in a clinical trial on medicinal products and the real or the presumed will of the test person. Involved in the study is the applicable International, European, German and Polish law, as well as the EU Regulation No 536/2014, which will soon unify the drug testing laws of the EU Member States.