Placebo use in research with commercial purposes: legal restrictions in the light of the Brazilian legal system

There are many ethical discussions about the use of placebo in research with humans. These discussions often occur from a bioethical standpoint, particularly in the light of the bioethical principles of autonomy, justice and equity. However, and without disregarding the importance of these discussions, the legal aspect should also be considered, particularly concerning medical research with commercial purposes. This article, from a literature interdisciplinary review, aims to discuss, in the light of the Brazilian legal system, how research using placebo and financed by laboratories and pharmaceutical companies should be tackled and how to assess the liability arising from this research in case of damage caused to the participants.