The dose makes the poison

"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.

• Dose concentration – Ratio of part of a mixture to the wholePages displaying short descriptions of redirect targets
• Forensic toxicology – Use of toxicology for investigations
• Homeopathy – Pseudoscientific system of alternative medicine
• Hormesis – Characteristic of biological processes
• Median lethal dose – Measurement of lethal dose of substance
• Therapeutic index – Quantitative measurement of the relative safety of a drug