The International Narcotics Control Board (INCB) is the independent and quasi-judicial control organ for the implementation of the United Nations drug conventions. It plays an important role in monitoring enforcement of restrictions on narcotics and psychotropics and in deciding which precursors should be regulated.
The Board has predecessors since the League of Nations. It all started in 1909 in Shanghai with the International Opium Commission, the first international drug control conference. The International Opium Convention of 1925 established the Permanent Central Board (first known as the Permanent Central Opium Board and then as the Permanent Central Narcotics Board). That Board started its work in 1929. After the dissolution of the League, the 1946 Protocol Amending the Agreements, Conventions and Protocols on Narcotic Drugs concluded at The Hague on 23 January 1912, at Geneva on 11 February 1925 and 19 February 1925, and 13 July 1931, at Bangkok on 27 November 1931 and at Geneva on 26 June 1936, created a Supervisory Body to administer the estimate system. The functions of both bodies were merged into the Board by the 1961 Single Convention on Narcotic Drugs. The composition of the Board under the Single Convention was strongly influenced by the 1946 treaty.
The drug control treaties divide power between the Board and the Commission on Narcotic Drugs. The Commission has power to influence drug control policy by advising other bodies and deciding how various substances will be controlled. However, enforcement power is reserved to the Board.
Article 9 of the Single Convention provides that the Board shall endeavour to:
Thus, the Single Convention seeks to allow medical and scientific use of psychoactive drugs while preventing recreational use. Accordingly, Article 12 gives the Board the responsibility of allocating quotas among Parties concerning licit cultivation, production, manufacture, export, import, distribution and trade in an attempt to prevent leakage of drugs from licit sources into the illicit traffic. The Board establishes estimates for all nations, including non-Parties to the Single Convention.
Article 18 of the Convention on Psychotropic Substances requires the Board to issue annual reports on its work.
Article 12 of the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances requires the Board to report annually to the Commission on the implementation of the Convention's restrictions on chemicals in Table I and Table II, the treaty's two categories of precursor substances in illicit drug manufacture. In the case of a precursor substance not yet regulated, the Convention also requires the Board to communicate to the Commission on Narcotic Drugs an assessment of the substance if it finds that:
The Convention requires the Board to notify the United Nations Secretary-General whenever it has information which, in its opinion, may justify adding a substance to, deleting a substance from, or transferring a substance between, the Tables. The Secretary-General then transmits that information to the Parties and the Commission, and the Commission makes the decision, "taking into account the comments submitted by the Parties and the comments and recommendations of the Board, whose assessment shall be determinative as to scientific matters, and also taking into due consideration any other relevant factors".
Article 14 of the Single Convention, Article 19 of the Convention on Psychotropic Drugs, and Article 22 of the Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances give the Board the authority to investigate the failure of any country or region to carry out the Convention's provisions. This includes countries that are not Parties to the Conventions. The Board can ask for explanations from the Government in question, propose that a study of the matter be carried out in its territory, and call upon the Government to adopt remedial measures.
If the Board finds that the Government has failed to give satisfactory explanations, or has failed to adopt remedial measures that it has been called upon to take, the Board can call the attention of the Parties, the Council, and the Commission to the matter. The Board can also publish a report on the matter for communication to all Parties. Under some circumstances, it can penalize a violator by reducing its export quota of opium, under the provisions of Article 21 bis. The Board can even "recommend to the Parties that they stop the export, import, or both, of particular psychotropic substances, from or to the country or region concerned, either for a designated period or until the Board shall be satisfied as to the situation in that country or region." The Commentary to the Convention on Narcotic Drugs points out, "This is a very serious measure, and it cannot be assumed that the Board has that authority except in very grave situations". Decisions under Article 19 require a two-thirds vote of the Board.
The Commentary to the Convention on Psychotropic Substances notes, "Since the Board is not in continuous session and in fact meets only a few weeks each year, it has to delegate to its secretariat the required authority in order to maintain between its sessions 'the mechanism for a continuing dialogue' with Governments".
Article 9 of the Single Convention specifies that the Board shall be made up of thirteen members elected by the UN Economic and Social Council, including:
The Article requires the Council to make arrangements to ensure the Board's independence. Article 10 specifies that "[t]he members of the Board shall serve for a period of five years, and may be re-elected." The lengthy terms, and the fact that the Board is made up of individuals rather than nation-states, help buffer the Board from political pressure. The requirement that members with "medical, pharmacological or pharmaceutical experience" be placed on the Board was the result of lobbying by the pharmaceuticals industry. The provision that three members would be WHO nominees is similar to the 1946 treaty's provision that two of the four members of the Supervisory Body would be appointed by the WHO. The requirement that nominees be appointed by ECOSOC is similar to the 1946 treaty's provision that one of the four members of the Supervisory Body be appointed by ECOSOC's Commission on Narcotic Drugs.
The INCB is criticised for their behaviour in urging sovereign states to stay in bounds of the conventions. It is not their place to comment on matters that are the sole purview of national governments. The move to a more political role combined with a very rigid interpretation of the drug control conventions, passing judgement on states, is considered problematic.
The Board routinely draws the attention of the international community to interesting drug control developments. On the United Kingdom, the report of the Board for 2002 noted “ the announcement by the Government of the United Kingdom that cannabis would be placed in a different schedule, requiring less severe controls, and the worldwide repercussions caused by that announcement, including confusion and widespread misunderstanding. A survey undertaken in the United Kingdom found that as many as 94 per cent of children believed that cannabis was a legal substance or even some type of medicine. The survey also discovered that nearly 80 per cent of teachers in the United Kingdom believed that the recent reclassification of cannabis would make educating pupils about the dangers of drug abuse more challenging and difficult. Several opinion polls taken in July and August 2002 found that the majority of the population did not support that reclassification.” (Paragraph 499, ) Parliamentary Under Secretary of State Bob Ainsworth responded:The comments made in your report, your selective and inaccurate use of statistics, and failure to refer to the scientific basis on which the UK Government's decision was based all add up to an ill-informed and potentially damaging message. This was compounded by the way in which the Board presented the cannabis reclassification decision to the media at the launch of its annual report on 26 February. For example, the Board representative is quoted as having said that we might end up in the next 10 or 20 years with our psychiatric hospitals filled with people who have problems with cannabis, and that a recent study by the British Lung Foundation found smoking three cannabis joints caused the same damage to the linings of the airways as 20 cigarettes. These are totally misleading statements.
In 2008, the Home Secretary of the United Kingdom recommended that cannabis be reclassified as a class B drug. 
In April 2003, former United Nations Drug Control Programme Chief of Demand Reduction Cindy Fazey penned a scathing review of the Board, accusing it of overstepping its bounds:Unfortunately these individuals also see their role not only as the guardians of the conventions, but also the interpreters of them as well. In their annual report they have criticised many governments, such as Canada for permitting the medicinal use of cannabis, Australia for providing injecting rooms and the United Kingdom for proposing to downgrade the classification of cannabis, which would entail less serious penalties than at present. These criticisms go far beyond their remit, and indeed it is hubris to criticise the Canadian Supreme Court.
In the wake of the United States Supreme Court's decision in Gonzales v. Raich, the Board welcomed "the decision of the United States Supreme Court, made on 6 June, reaffirming that the cultivation and use of cannabis, even if it is for 'medical' use, should be prohibited." The Board's President, Hamid Ghodse, opined:INCB has for many years pointed out that the evidence that cannabis might be useful as a medicine is insufficient. Countries should not authorise the use of cannabis as a medicine until conclusive results based on research are available. Sound scientific evidence for its safety, efficacy and usefulness is required to justify its use in medical practice. Any research into cannabis as a medicine should involve the World Health Organization, as the responsible international health agency.
The Senlis Council has argued in March 2006 that the INCB is not taking seriously its responsibility vis-à-vis the global needs for medicines:The INCB is responsible for ensuring adequate supplies of drugs for medical use. Currently millions of people are suffering due to a mounting global shortage of opium-based painkillers such as morphine and codeine, especially in the developing world. The methods used by the INCB to calculate the amounts needed of these medicines are flawed and need to be reconsidered.
The INCB has published several special reports on the availability of opiates for medical needs, going back to 1989 and 1995  and has repeatedly called for urgent global action to address the situation .
In its most recent report, noting that millions of people around the world are suffering from acute and chronic pain, the INCB calls on Governments to support a new programme of the World Health Organization (WHO), which aims at improving access to those medicines.