This paper reimagines drug policy – specifically psychedelic drug policy – through the prism of human rights. Challenges to the incumbent prohibitionist paradigm that have been brought from this perspective to date – namely by calling for exemptions from criminalisation on therapeutic or religious grounds – are considered, before the assertion is made that there is a need to go beyond such reified constructs, calling for an end to psychedelic drug prohibitions on the basis of the more fundamental right to cognitive liberty. This central concept is explicated, asserted as being a crucial component of freedom of thought, as enshrined within Article 9 of the European Convention on Human Rights (ECHR). It is argued that the right to cognitive liberty is routinely breached by the existence of the system of drug prohibition in the United Kingdom (UK), as encoded within the Misuse of Drugs Act 1971 (MDA). On this basis, it is proposed that Article 9 could be wielded to challenge the prohibitive system in the courts. This legal argument is supported by a parallel and entwined argument grounded in the political philosophy of classical liberalism: namely, that the state should only deploy the criminal law where an individual’s actions demonstrably run a high risk of causing harm to others.