• 
  Saleyha Ahsan

   Presenter (unknown episodes)
• 
  Michael Mosley

  2 episodes, 2017-2018
• 
  Angela Rippon

  2 episodes, 2016-2019
• 
  Mehreen Baig

  Self - Presenter
• 
  Javid Abdelmoneim

   Himself - Host (1 episode, 2016)
• 
  Fiona Phillips

   Herself - Presenter (2 episodes, 2015-2016)
• 
  Chris van Tulleken

   Himself - Presenter (4 episodes, 2015-2017)
• 
  Serpil Djemal

  Self - Restorative Dentistry

• 
  Jasmine Harman

  Self - Presenter
• 
  Chris Bavin

  Self - Presenter
• 
  Alexander van Tulleken

  Self - Presenter
• 
  Tanya Byron

  Self - Presenter
• 
  Matthew Mitchell

  Self - U.K. Country Manager, Alcohol Monitoring Systems
• 
  Alex Scott

  Self - Presenter
• 
  Gautam Mehta

  Self - Liver Specialist, Royal Free Hospital

• 
  Antony Moss

  Self - M.D., London South Bank University
• 
  Paul Huff

  Self - Sports Scientist
• 
  Celia Morgan

  Self - Professor of Psychopharmacology, University of Exeter