Background: The 2016 United Nations General Assembly's Special Session on the World Drug Problem (UNGASS) was a â€˜critical momentâ€™ in recent global drug policy history. Methods: This study examines the dynamics and consequences of UNGASS 2016 using documentary analysis and interviews with ten leading international drug reform experts. Results: International consensus relating to the global drug problem remains heavily fractured. This is evident from: the increasingly diverse positions adopted by Member States during the negotiation period leading up to UNGASS; conflicting agendas within and between different United Nations agencies; and the content of the UNGASS Outcome Document. Our interviews further revealed key obstacles facing the international drug policy reform community following this event. Conclusion: Global governance in the sphere of drug policy has reached an impasse but this should have limited impact on the ongoing efforts of reformers to shift the debate so long as civil society actors have access to funding and opportunities to participate in key future global drug policy events.