December/January 2021/2022 (vol. 18/4)

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The dose (for anything) makes the poison

Why Paracelsus’s famous axiom works for OH


The 16th century toxicologist, Paracelsus, was famous for saying, ‘the dose makes the poison.’ Dr Greg Couser explains why this is generally true not just for toxicology but for anything in life, including work.

Phillipus Aureolus Theophrastus Bombastus von Hohenheim (1493–1541), better known as Paracelsus, was often considered as the father of toxicology. He was a Renaissance physician, well known for his views regarding the dose–response concept, summarised by maxim: ‘the dose makes the poison’. His thoughts paved the way for the modern threshold concept of dose. Paracelsus’s thinking was novel as he emphasised that lower doses – ie below a threshold – could cause otherwise poisonous substances to become harmless.

Although Paracelsus studied chemicals and their health impact, his ‘dose makes the poison’ concept applies well beyond toxicology. Finding the right balance for anything we do in life and at work requires the right dose titrated by gathering applicable facts…


Greg P Couser, MD, MPH, is a consultant at Mayo Clinic in Rochester, Minnesota, US, where he is the medical director of the employee assistance programme. He has formal residency training and board certification both in psychiatry and in occupational medicine.

Author: Couser G


Occupational Health at Work December/January 2021/2022 (vol. 18/4) pp17-21

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