Dr Rachel Barry is internationally recognised for her research on cannabis regulation and its implications for health (and broader agendas such as crime and finance) and on cannabis and related industries. This work has stimulated extensive policy and academic discussions on the health implications of commercial cannabis markets.

Background Several jurisdictions are considering legalising cannabis and developing new regulatory frameworks to deliver on this agenda. Simultaneously, a complex and increasingly profitable industry is rapidly emerging, with major tobacco and alcohol companies having made recent investments in this nascent market. Despite these developments, no studies have investigated the structure and tactics of the global cannabis industry, and the role of transnational corporations, notably those that produce harmful products, is poorly understood. This study aims to map and analyse the key corporations operating within the global cannabis market, examining their links to other industries and discussing the implications for public health policy.

Methods We identified and ranked the top 10 cannabis companies by size using 2023 sales revenue data. Drawing on corporate websites, annual reports and investor presentations, we analysed the nature, reach and investment strategies of these companies using qualitative content analysis. Data on the characteristics of structural links across major cannabis, tobacco, alcohol, food and pharmaceutical companies were further extracted for analysis, including investment year, deal type, amount and rationale.

Results Despite offering diverse portfolios, the world’s leading cannabis companies are increasingly operating as recreational cannabis firms, with a majority of their brands, products and sales generated from non-medical cannabis markets at national level. While cannabis companies have diverse industry representation on their directorates, tobacco and alcohol companies demonstrate the most significant depth of integration, holding majority ownership stakes and serving on cannabis company boards or within management. Investment by transnational corporations seemingly enabled Canadian cannabis firms to expand internationally into European medical cannabis markets and the US alcohol sector.

Conclusion These findings lend weight to concerns about the potential risk of corporate domination of the global cannabis market. This highlights a need to examine the role of transnational corporations in shaping new systems of cannabis governance.