Mexico’s Supreme Court Paves the Way for Cannabis Legalization

Five Rulings, One Outcome: Mexico’s Judiciary Forces Cannabis Reform

Published June 28, 2020 — By Ann Karim, Senior Cannabis Editor

How Mexico’s Judiciary Ran Ahead of Its Legislature

Mexico’s cannabis reform story is one of judicial leadership in the face of legislative inaction — a pattern that has produced cannabis reform in several countries where courts moved before parliaments. The story begins in 2015, when the organization SMART (Sociedad Mexicana de Autoconsumo Responsable y Tolerante) filed the first constitutional challenge to cannabis prohibition. The SCJN ruled in SMART’s favor in 2015, but that single ruling was not enough to create jurisprudencia.

Under Mexico’s legal system, the mechanism of jurisprudencia requires five consistent rulings from the full bench of the Supreme Court or ten from specific chamber panels. Once established, jurisprudencia is binding on all lower courts — meaning any individual could file an amparo (constitutional protection) petition and receive personal legal relief from cannabis prohibition. More importantly, jurisprudencia creates an obligation on the legislature to amend the unconstitutional law.

The SCJN’s series of rulings through 2018-2021 built this jurisprudencia methodically. Each ruling reinforced the constitutional analysis: that decisions about adult recreational cannabis use fall within the constitutionally protected right to the free development of personality, that prohibition is a disproportionate means of achieving public health goals, and that the criminal penalties imposed on personal users are incompatible with Mexico’s constitutional framework. For context on the global legal landscape, Mexico’s judicial route to reform represents a third pathway alongside legislative reform and popular referendum.

“The prohibition of cannabis use is disproportionate, because it violates the right to the free development of personality without justification in terms of harm to third parties.” — Mexico Supreme Court (SCJN), 2020

The Constitutional Analysis: What Rights Did Prohibition Violate?

The SCJN’s constitutional analysis focused primarily on the right to the free development of personality (libre desarrollo de la personalidad) — a broad autonomy right derived from Mexico’s constitutional dignity protections. The court reasoned that recreational cannabis use, when it affects primarily the individual user, is the type of personal lifestyle decision that falls within the protected sphere of individual autonomy. Criminalizing such decisions requires the state to demonstrate that prohibition is a necessary and proportionate means of protecting compelling interests.

The court found that prohibition failed this proportionality test. Cannabis use does not harm third parties in the way that criminal prohibition requires to be constitutionally justified. The public health harms of cannabis, while real, are not of a severity that justifies criminal enforcement against adult users making personal choices. The availability of less restrictive alternatives — regulation rather than prohibition — further undermined the proportionality of the criminal approach.

This rights-based analysis closely paralleled South Africa’s 2018 Constitutional Court ruling on South African cannabis privacy rights, Canada’s political framing of legalization as a public health measure, and Portugal’s 2001 decriminalization. The convergence of constitutional and rights-based arguments across multiple legal systems in multiple countries provided a coherent international jurisprudential framework for cannabis reform that transcended any single national context. The medical dimension also featured in the Mexican analysis, as evidence of cannabis’ therapeutic applications undermined the “no legitimate use” premise underlying Schedule IV prohibition.

Congressional Delays and the Jurisprudencia Deadline

Once the SCJN’s rulings created jurisprudencia, the Mexican Congress faced a constitutional obligation to amend the Health Law and Federal Penal Code to bring them into compliance. The court set deadlines for Congress to act — and Congress repeatedly missed them. The first deadline passed in April 2020. The second passed in December 2020. The third passed in April 2021. Each missed deadline drew formal disapproval from the Supreme Court but no immediate enforcement mechanism that could compel legislative action.

The delays reflected the genuine complexity of cannabis legislation in a country with Mexico’s security dynamics. Mexico had been fighting a devastating drug war for over a decade, with cannabis trafficking a significant revenue source for organized crime groups. Legalization supporters argued that a regulated market would cut criminal revenue; opponents worried about implementation challenges and the diplomatic signals legalization would send to the United States, which had long pressured Mexico on drug enforcement.

Congress eventually passed the Cannabis Institute Act in 2021, establishing a legal framework for cultivation, processing, and personal use, with a regulatory agency (CANNA) to oversee the market. Implementation of a retail licensing system remained ongoing as of 2024. Mexico’s legalization process demonstrated that judicial mandates accelerate reform but do not guarantee smooth or rapid implementation — a lesson applicable to cannabis reform in every jurisdiction.

Geopolitical Impact: What Mexico’s Reform Means for the US and Latin America

Mexico’s movement toward cannabis legalization created significant pressure on US federal policy. With both of the United States’ land-border neighbors — Canada to the north and Mexico to the south — having reformed cannabis law, the US federal prohibition position became increasingly anomalous and diplomatically awkward. The US had historically pressured Mexico heavily on drug enforcement; Mexico’s domestic judicial reform of cannabis law represented a degree of policy sovereignty that was difficult for Washington to openly oppose.

For Latin America, Mexico’s Supreme Court jurisprudencia was as significant as Canada’s national legalization had been for global policy. Mexico is the largest Spanish-speaking country in the world and the most populous country in Latin America. Its constitutional court declaring cannabis prohibition a rights violation provided a model and precedent for reform advocates in Colombia, Argentina, Chile, and Brazil, all of which had their own domestic reform conversations underway.

For drug testing implications at the US-Mexico border, Mexico’s legal shift did not affect US customs enforcement: cannabis remains a federally prohibited substance for US border crossing purposes regardless of Mexico’s domestic law. Travelers need to understand that cannabis purchased or used legally in Mexico cannot be transported across the border. Our travel guide covers what you need to know for North American cannabis travel in the evolving regulatory landscape that Mexico’s reform created.