Pharmacology & Biology
Pharmacokinetics (PK)
Also called: PK
Definition
The study of how a drug or compound moves through the body over time, including absorption, distribution, metabolism, and elimination.
What Pharmacokinetics (PK) means
Pharmacokinetic measurements can include peak concentration, time to peak, overall exposure, clearance, and half-life.
Why the distinction matters
PK describes exposure over time. It does not by itself tell you whether the compound produces a beneficial clinical effect.
Common confusion
Pharmacokinetics is often paired with pharmacodynamics, but the two answer different questions: exposure versus biological effect.
Keep learning
Related glossary terms
Pharmacology & Biology
Half-Life
The time required for the amount or concentration of a substance in a defined system to fall to one-half of a reference value.
Pharmacology & Biology
Pharmacodynamics (PD)
The study of what a drug or compound does to a biological system, including target engagement and measurable effects.
Research & Regulation
Phase 1 Clinical Trial
An early stage of human clinical development that commonly emphasizes safety, tolerability, pharmacokinetics, and dose-ranging information.
Published September 6, 2026. BACToBasics glossary pages are educational definitions only and do not provide medical, dosing, preparation, treatment, or product-selection advice.