the time required for 50 percent of an administered drug, xenobiotic, chemical or radionuclide to be cleared from a tissue, organ or body.
This is the amount of time it takes for the human body to eliminate 50 percent of a radioactive substance through natural excretory functions: urination, defecation, exhalation, and perspiration.
the time required for one half of the amount of a substance, such as a radionuclide, to be expelled from the body by natural metabolic processes, not counting radioactive decay, once it has been taken in through inhalation, ingestion, or absorption. See also radioactive half-life, effective half-life.
The time required for the body to eliminate by biological processes one-half of the amount of a substance which has entered it.
The time required for a biological system, such as that of a human, to eliminate by natural process half of the amount of a substance (such as a chemical substance or radioactive material) that has entered it.
The time required for a biological system (such as a human or animal) to eliminate, by natural processes, half the amount of a substance (such as a radioactive material) that has been absorbed into that system.
t1/2): Time required for the amount of a substance in a biological system to be reduced to one-half, predominantly by biological processes, when the rate of removal is approximately exponential. Gold, Loening, McNaught and Sehmi, 1987
The biological half-life of a substance is the time required for half of that substance to be removed from an organism by either a physical or a chemical process. Biological half-life is an important pharmacokinetic parameter and is usually denoted by the abbreviation t1/2.
