The relationship between the compound dose plotted on the X-axis and the effect on the biological function plotted on the Y-axis.

Graphing dose-response curves is broadly used in pharmacology and helps determine the dose necessary to achieve the desired effect. In pharmacokinetics (PK)/ pharmacodynamics (PD)-modelling, the dose-response relationship describes the change in effect on a microbe caused by differing levels of drug doses after a certain exposure time. It provides information such as the maximal efficacy (Emax) and the effective dose in 50% of the population (ED50). Dose-response curves are based on pharmacokinetics and pharmacodynamics principles and are vitally important for determining appropriate dosages for drugs.