Ahsan Ahmad is a Research Associate at the Department of Medicine, Section of Infectious Diseases, AIDS Program at the Yale School of Medicine and a visiting Research Associate at the Centre of Excellence for Research in AIDS (CERiA), at University Malaya, Faculty of Medicine, in Kuala Lumpur, Malaysia. Currently, he is managing a 5-year grant from the National Institute on Drug Abuse (Grant#: 1R01DA041271) examining addiction, HIV, and tuberculosis in the Malaysian criminal justice setting. His current work is on the nexus of infectious disease epidemiology, substance use and addiction, prison and detention health, migrant health, human rights, and drug policy in Southeast Asia. Serving as the Program Director for the All-Party Parliamentary Group for the Reform of Prisons and All Places of Detention (APPG) Secretariat, and the founding Secretariat for the Malaysian Alliance for Drug Policy Reform at CERiA, a think tank of multi-sector leaders and influencers researching and advocating for evidence-based drug policy—funded by Open Society Foundations, and supported by national and international agencies—his work demonstrates strategic investment in data-driven, evidence-based health policymaking in the region. Ahsan also explores disproportionate sentencing in relation to drug crimes in the wider area of criminal justice policies on drugs, with particular focus on drug threshold quantities, prisons, and the death penalty in Southeast Asia at the Death Penalty Research Unit, at the Faculty of Law, at Oxford University.