This publication examines the effective regulation and governance practices of the pharmaceutical sector in the Greater Mekong Subregion. Disease control and prevention, already a challenging task in resource-constrained environments, is adversely affected by weak regulation. For example, in Asia and the Pacific as a whole, and the Greater Mekong Subregion (GMS) in particular, National Regulatory Agencies are not yet well equipped to support the elimination of malaria, a goal that governments across the region are committed to achieving by 2030. Unregulated medicines in the supply chain, including fake and substandard medicines, are fueling resistance to artemisinin combination therapies, the key and most effective treatment for malaria. This is undermining the region’s drive to achieve elimination of malaria as a public health threat by 2030.