"
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.