The dose makes the poison

"The dose makes the poison" (Latin:''sola dosis facit venenum'') 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; only the dose makes a thing 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).