Nuremberg Code

The Nuremberg Code is a ten-point statement of ethical principles for research involving human subjects, articulated in the verdict of the U.S. military tribunal in United States v. Karl Brandt et al. — the “Doctors’ Trial” — delivered on August 19, 1947, in Nuremberg, Germany. It is widely recognized as the first internationally established code of research ethics, and its foundational principle — that the voluntary, informed consent of the human subject is “absolutely essential” — remains the conceptual origin point for informed-consent requirements in every research-ethics framework that followed it, including the Belmont Report and the Common Rule (45 CFR 46).

Origin: the Doctors’ Trial

The Code emerged directly from a war-crimes prosecution, not from a standards body or professional association. Between December 1946 and August 1947, an American military tribunal at Nuremberg tried 23 defendants, most of them physicians, on charges including the conduct of involuntary, often fatal, medical experiments on concentration-camp prisoners — among them high-altitude and hypothermia experiments, forced infection studies, and induced-injury experiments, carried out without the subjects’ consent and frequently causing death, permanent injury, or severe suffering. Dr. Leo Alexander, an American physician assisting the prosecution, submitted a memorandum in April 1947 setting out six proposed points on the ethics of legitimate human experimentation. The tribunal’s final judgment, in a section titled “Permissible Medical Experiments,” expanded these into ten points, which have since been known as the Nuremberg Code. Unlike the Declaration of Geneva adopted the following year by the newly formed World Medical Association, the Code was not written as a professional charter; it was written as the legal standard the tribunal used to distinguish permissible research from the criminal conduct it had just adjudicated.

The ten principles

1. Voluntary consent is absolutely essential. The subject must have legal capacity to consent, must be able to exercise free power of choice without force, fraud, deceit, duress, or other constraint, and must have sufficient knowledge and comprehension of the experiment’s nature, duration, purpose, methods, and foreseeable risks to make an informed decision. The Code places responsibility for ensuring this squarely on the individual who initiates, directs, or engages in the experiment — a personal, non-delegable duty.
2. The experiment should be designed to yield results for the good of society that are unprocurable by other methods of study, and not random or unnecessary in nature.
3. The experiment should be based on results of prior animal experimentation and knowledge of the natural history of the disease or problem under study, such that anticipated results justify performing the experiment.
4. The experiment should be conducted so as to avoid all unnecessary physical and mental suffering and injury.
5. No experiment should be conducted where there is a prior reason to believe death or disabling injury will occur, except perhaps where the experimenting physicians also serve as subjects.
6. The degree of risk to be taken should never exceed that determined by the humanitarian importance of the problem to be solved by the experiment.
7. Proper preparations and adequate facilities should be provided to protect the subject against even remote possibilities of injury, disability, or death.
8. The experiment should be conducted only by scientifically qualified persons, exercising the highest degree of skill and care throughout.
9. The human subject should be free to bring the experiment to an end at any point if they have reached a physical or mental state where continuation seems impossible.
10. The scientist in charge must be prepared to terminate the experiment at any stage if there is probable cause to believe that continuation is likely to result in injury, disability, or death to the subject.

Taken together, the ten points establish three things that had no prior codified statement in international law: that consent must be voluntary and informed rather than assumed or coerced; that a study’s scientific justification and expected value must be weighed against its risk to the people bearing that risk; and that the obligation to protect the subject, including by stopping the study, continues for the entire duration of the research rather than ending once it begins.

Legal status and immediate impact

The Code was not enacted as binding legislation in any country, including the United States and Germany, and had no direct enforcement mechanism of its own. Its immediate practical effect was narrow: it served as the standard the Nuremberg tribunal itself used to convict several of the defendant physicians and to distinguish their conduct from legitimate research. For roughly two decades afterward, it functioned mainly as a moral reference point rather than an operative rule that oversight bodies applied — a gap now widely cited (including in retrospective accounts of the Belmont Report’s own origins) as part of the reason abuses such as the Tuskegee Syphilis Study were able to continue for years after the Code existed.

Influence on later frameworks

The Nuremberg Code’s principles were carried forward, elaborated, and in some cases modified by every major research-ethics document that followed it:

• Declaration of Helsinki (1964, World Medical Association). Adopted as a professional ethical statement specifically for physicians conducting medical research, it retained the Code’s emphasis on consent and risk-benefit justification but introduced a distinction between therapeutic and non-therapeutic research and allowed, under specified safeguards, consent by a legally authorized representative for subjects who cannot themselves consent — a departure from the Nuremberg Code’s near-absolute individual-consent requirement. It has been revised repeatedly since, most recently in October 2024, and remains the primary international ethical statement for physician-led medical research, though it is a professional-association statement rather than binding law in most jurisdictions.
• The Belmont Report (1979). Issued by the U.S. National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research following the Tuskegee revelations, it distilled research ethics into three principles — respect for persons, beneficence, and justice — each linked to a concrete application (informed consent, risk/benefit assessment, and equitable subject selection). Belmont’s respect-for-persons principle is a direct descendant of the Nuremberg Code’s first point, generalized from an absolute rule into a principle applied case-by-case, including to subjects who lack full autonomy to consent for themselves.
• The Common Rule (45 CFR 46) and Institutional Review Board (IRB) review. The U.S. federal regulation that operationalizes Belmont’s principles — and therefore, at two removes, the Nuremberg Code’s — into binding procedural requirements: informed-consent documentation, IRB risk/benefit determinations, and additional safeguards for subjects likely to be vulnerable to coercion.

Every one of these later frameworks preserves the Nuremberg Code’s central claim — that voluntary, informed consent is a precondition for legitimate human research — while relaxing its most absolute features (in particular, its near-total exclusion of subjects who cannot personally consent) to accommodate research such as pediatric or emergency medicine that the Code’s original ten points did not contemplate.

Why it still matters to research administrators

Research administrators, IRB coordinators, and investigators rarely cite the Nuremberg Code directly in a protocol review today — the operative standard is the Common Rule, FDA human-subjects regulations, or an equivalent national framework. But the Code remains the reference point taught in every human-subjects research-ethics training curriculum, because it is the document that first established, in a legally binding context, that scientific value and researcher intent do not by themselves justify research on a person who has not voluntarily and knowingly agreed to take part. Understanding the Code is understanding why informed consent, risk/benefit review, and the right to withdraw are treated as non-negotiable minimums rather than best practices, in every framework that came after it.

References

• Trials of War Criminals before the Nuernberg Military Tribunals under Control Council Law No. 10, Vol. 2, “The Medical Case” (verdict of August 19, 1947), section “Permissible Medical Experiments.”
• United States Holocaust Memorial Museum, Holocaust Encyclopedia, “The Nuremberg Code” (encyclopedia.ushmm.org).
• World Medical Association, Declaration of Helsinki (1964, as revised, most recently October 2024).
• National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research, The Belmont Report (1979).