 The World Medical Association has adopted the Declaration of Helsinki to protect human subjects and maintain ethical standards in medical research. The latest revision, adopted in 2013, made four substantial changes, compensation for trial-related injuries, approval of placebo's, protection of vulnerable groups, and post-trial provisions. These amendments have implications for clinical research involving human subjects, including the need for informed consent and the importance of protecting vulnerable populations. This article was authored by Badri Shrestha and Louise Dunne.