The dose makes the poison

For the book, see The Dose Makes the Poison.

Alle Dinge sind Gift, und nichts ist ohne Gift; allein die Dosis macht, dass ein Ding kein Gift ist.
All things are poison, and nothing is without poison; the dosage alone makes it so a thing is not a poison.

—Paracelsus, 1538[1]

"The dose makes the poison" (Latin: dosis sola facit venenum 'only the dose makes the poison') is an adage intended to indicate a basic principle of toxicology. It is credited to Paracelsus who expressed the classic toxicology maxim "All things are poison, and nothing is without poison; the dosage alone makes it so a thing is not a poison." This is often condensed to: "The dose makes the poison" or in Latin, "Sola dosis facit venenum". It means that a substance can produce the harmful effect associated with its toxic properties only if it reaches a susceptible biological system within the body in a high enough concentration (i.e., dose).[2]

The principle relies on the finding that all chemicals—even water and oxygen—can be toxic if too much is eaten, drunk, or absorbed. "The toxicity of any particular chemical depends on many factors, including the extent to which it enters an individual’s body."[3] This finding also provides the basis for public health standards, which specify maximum acceptable concentrations of various contaminants in food, public drinking water, and the environment.[3]

The idea also describes the phenomenon in which poisonous substances can be medicinal in small doses.

  1. ^ "Die dritte Defension wegen des Schreibens der neuen Rezepte," Septem Defensiones 1538. Werke Bd. 2, Darmstadt 1965, p. 510 (full text)
  2. ^ "The Dose Makes the Poison". Chemistry. Chemsafe. Yale University. Archived from the original on 2011-02-02. Retrieved 2022-08-13. A substance can produce the harmful effect associated with its toxic properties only if it reaches a susceptible biological system within your body in a sufficient concentration
  3. ^ a b Trautmann, Nancy (September 2005). "The Dose Makes the Poison-Or Does It?". BioScience. 55 (9). American Institute of Biological Sciences: 809–810. Archived from the original on 2005-11-17. Retrieved 3 August 2023.