Nuremberg Code:
①The voluntary consent of the human subject is absolutely essential.
②The experiment should be such as to yield fruitful results for the good of society, unprocurable by other methods or means of study,…not random…unnecessary in nature.
https://www.ushmm.org/information/exhibitions/online-exhibitions/special-focus/doctors-trial/nuremberg-code

③experiment should be so designed …natural history of the disease …that the anticipated results will justify the performance of the experiment.
④The experiment should be so conducted as to avoid all unnecessary physical and mental suffering and injury.

⑤No experiment should be conducted where there is an a priori reason to believe that death or disabling injury will occur; except, perhaps, in those experiments where the experimental physicians also serve as subjects.

⑥The degree of risk to be taken should never exceed that determined by the humanitarian importance of the problem to be solved by the experiment.

⑦Proper preparations should be made and adequate facilities provided to protect the experimental subject against even remote possibilities of injury, disability, or death.

⑧The experiment should be conducted only by scientifically qualified persons. The highest degree of skill and care should be required through all stages of the experiment of those who conduct or engage in the experiment.

⑨During the course of the experiment the human subject should be at liberty to bring the experiment to an end if he has reached the physical or mental state where continuation of the experiment seems to him to be impossible.

⑩During the course of the experiment the scientist in charge must be prepared to terminate the experiment at any stage, if he has probably cause to believe, it is…likely to result in injury, disability, or death to the experimental subject.