 Biography (2004) (TV Series)-Self - Toxicology Expert, St. Mary's Hospital (1 episode, 2004) Self - Toxicology Expert, St. Mary's Hospital (1 episode, 2004) See fewerTchaikovsky (2004) Self - Toxicology Expert, St. Mary's Hospital Self - Toxicology Expert, St. Mary's Hospital See fewer |
 Ali G, Aiii (2000) (Video)-Self - Professor from NPIS Self - Professor from NPIS See fewer |
 Da Ali G Show (2000) (TV Series)-Self (1 episode, 2000) Self (1 episode, 2000) See fewerMohamed Al-Fayed (Apr 7, 2000) Season 1, Episode 2-Self (as Professor Jon Henry) Self (as Professor Jon Henry) See fewer |
 Equinox (1994–1999) (TV Series)-Self - St Mary's Hospital / Self - Cosultant Toxicologist, Guy's Hopsital / Self - Consultant Physician, National Poisons Unit (3 episodes, 1994) Self - St Mary's Hospital / Self - Cosultant Toxicologist, Guy's Hopsital / Self - Consultant Physician, National Poisons Unit (3 episodes, 1994) See fewerLiving Dangerously (Apr 12, 1999) Season 14, Episode 1-Self - St Mary's Hospital (as Prof John Henry) Self - St Mary's Hospital (as Prof John Henry) See fewer |
 Short Circuit (1996) (TV Series)-Self - Medical Toxicology Unit (1 episode, 1996) Self - Medical Toxicology Unit (1 episode, 1996) See fewerHomeostasis (Nov 1, 1996) Self - Medical Toxicology Unit (as Dr John Henry) Self - Medical Toxicology Unit (as Dr John Henry) See fewer |
 The London Programme (1994) (TV Series)-Self - National Poisons Unit (1 episode, 1994) Self - National Poisons Unit (1 episode, 1994) See fewerJust Say Yes (Mar 27, 1994) Self - National Poisons Unit (as Dr John Henry) Self - National Poisons Unit (as Dr John Henry) See fewer |
| E for Ecstasy (1993) (TV Special)-Self - National Poisons Unit (as Dr. John Henry) Self - National Poisons Unit (as Dr. John Henry) See fewer |
 The Cook Report (1992) (TV Series)-Self - National Poisons Unit (1 episode, 1992) Self - National Poisons Unit (1 episode, 1992) See fewerEcstacy Kills (Jun 3, 1992) Season 6, Episode 6-Self - National Poisons Unit (as Dr. John Henry) Self - National Poisons Unit (as Dr. John Henry) See fewer |
| Mushroom Magic (1989) (TV Series)-Self - National Poisons Information Service Self - National Poisons Information Service See fewer |