[Analysis of the main ethical conflicts in the 2008 declaration of Helsinki and the proposed changes in the new version].

The Declaration of Helsinki (DoH) of the World Medical Association is the basis of the rules governing research on human beings. The latest version (enacted in Korea, 2008) has been a source of ethical discussions, particularly regarding the use of placebos, the measures to assure the access of study subjects to interventions identified as beneficial once the study has ended, and the need of a better protection of potentially vulnerable groups. These issues led to draft a revised version, that was approved in 2013. In this paper, we present an ethical analysis of the main changes contained in the DoH, including the proposed changes in the new version, referring, when appropriate, to relevant Chilean laws governing research on human subjects. In our opinion, the 2008 DoH contains significant imprecisions on some of these issues, making a new version of the declaration necessary to fully protect subjects participating in biomedical research, as stated by the new version approved in 2013.