This article reviews and critiques the International Narcotic Control Board’s (INCB) 2010 Annual Report’s recommendation about plant materials containing psychoactive substances. It first provides an overview of the United Nations drug control system, then contextualises the INCB’s role in the UN system. Through a reading of the text of the INCB’s 2010 Report and references to contemporary practices of ayahuasca drinking based in fieldwork, the article shows how this Report fits into the international paradigm of the war on drugs and its conflicts with human rights. It is argued that the Board’s recommendation demonstrates an unwarranted attempt to extend the scope of its powers, conflates and thus misrepresents widely diverse plant materials and their effects, fails to distinguish between ‘use’ and ‘abuse’ of psychoactive substances and appears to assume that particular elements of culture — specifically, traditions involving psychoactive substance use — are, or should be, static, eternally frozen in time and place.