Many current innovative medicinal products under research and development comprise active substances composing of nanoparticles as fundamental building blocks. Studies show that physicochemical and biological properties of materials can alter dramatically at nanoscopic scale, and therefore, the growing use of nanomaterials in medicinal products requires the application of suitable strategies in human health risk assessment processes. In this article, the paradigm of toxicology studies to assess the preclinical safety of medicinal nanoproducts is discussed. New goals and challenges in the field of nanotoxicological researches are also elucidated.