In this opinion piece, Sir Richard Branson and Maria Cattaui highlight the need for an effective regulatory framework for the growing international medical cannabis production and trade. Indeed, legalization is helping to end many of the harms related to decades-old prohibition; we must now ensure that we do not create new harms and instead provide a framework that furthers sustainable development goals, avoids over-commercialization, and is mutually beneficial to corporations and small-scale actors.