Michael J. Mosley
В роли: Self - Presenter

Druin Burch
В роли: Self - Author 'Taking the Medicine' (как Dr Druin Burch)

Andrea Sella
В роли: Self - Department of Chemistry, University College London (как Prof Andrea Sella)

Walter Sneader
В роли: Self - Former Head of the School of Pharmacy, University of Strathclyde (как Dr Walter Sneader)

Stephanie Snow
В роли: Self - Centre for History of Science, Technology and Medicine, University of Manchester (как Dr Stephanie Snow)

David Wilkinson
В роли: Self - Emeritus Consultant Anaesthetist, St. Bartholomew's Hospital, London (как Dr David Wilkinson)

Austin Leach
В роли: Self - Consultant Anaesthetist (как Dr Austin Leach)

Dr. Michael Hayden
В роли: Self - Centre for Molecular Medicine and Therapeutics, University of British Columbia (как Dr Michael Hayden)