Pharmacology
Agonist
An agonist is a molecule that binds to a receptor and activates it, producing a biological response similar to the natural ligand.
Detailed Explanation
Agonists can be full (producing the maximal response) or partial (producing a submaximal response). Many therapeutic peptides are receptor agonists — for example, Semaglutide is a GLP-1 receptor agonist, Ipamorelin is a ghrelin receptor agonist, and Tesamorelin is a GHRH receptor agonist. Agonists are distinct from antagonists, which block receptor activity.