Dyfrig graduated in pharmacy at Cardiff University before undertaking a PhD in cardiovascular pharmacology at the University of Liverpool. He subsequently re-trained in health economics, and is currently Professor of Pharmacoeconomics and co-director of the Centre for Health Economics and Medicines Evaluation at Bangor University. He is also academic lead for Pharmacy at the Betsi Cadwaladr University Health Board, and is honorary professor at the Department of Molecular and Clinical Pharmacology, University of Liverpool. He has led the pharmacoeconomic activities of the All Wales Therapeutics and Toxicology Centre, contributing to over 200 substantive HTA reports. He was inaugural president of the European Society for Patient Adherence, Compliance and Persistence (ESPACOMP) and was elected fellow of: the Learned Society of Wales, the British Pharmacological Society, and the Faculty of the Royal Pharmaceutical Society. Dyfrig's main research activities, which have led to over 120 publications, concern pharmaceutical economics and policy, health technology assessment and medication adherence. He is an editorial board member of the journals PharmacoEconomics and Clinical Pharmacology & Therapeutics.