Pharmacology & Biology
Pharmacodynamics (PD)
Also called: PD
Definition
The study of what a drug or compound does to a biological system, including target engagement and measurable effects.
What Pharmacodynamics (PD) means
Pharmacodynamic evidence can include receptor effects, biomarkers, physiological changes, and clinical outcomes depending on the study.
Why the distinction matters
PD is related to but distinct from pharmacokinetics: a measured concentration does not automatically translate into a particular biological or clinical effect.
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Related glossary terms
Pharmacology & Biology
Pharmacokinetics (PK)
The study of how a drug or compound moves through the body over time, including absorption, distribution, metabolism, and elimination.
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Receptor
A biological molecule, often a protein, that can respond when a signaling molecule or drug binds to it.
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Agonist
A molecule that binds to a receptor and activates signaling through that receptor.
Published September 6, 2026. BACToBasics glossary pages are educational definitions only and do not provide medical, dosing, preparation, treatment, or product-selection advice.