What do dose-response curves tell about drugs?
The graph shows the dose-response curves of 2 drugs (blue and red) that elicit the same response (effect). The upper graph is displayed on a linear or arithmic scale; the lower uses a logarithmic scale for the dose on the x-axis.
The EC50 is a measure for the potency of a drug, which is equal to the dose (concentration) at which the drug elicits 50% of its maximal effect.
The blue drug is more potent, because it requires a lower dose in order to elicit 50% of the maximal response.
The following topics will give more information on dose-response curves. From now on, we will talk about drugs instead of ligand and about dose or concentration.
Switch from linear to log scale here and selecting linear vs. log scale (module 1).