Pharmacology
Receptor Agonist
Definition
A receptor agonist is a molecule that binds to a biological receptor and activates it, mimicking the effect of the endogenous ligand to produce a biological response. Agonists can be classified as full agonists (producing maximal receptor activation), partial agonists (producing submaximal activation even at saturating concentrations), or superagonists (producing a greater response than the natural ligand). Many research peptides function as receptor agonists, such as GLP-1 receptor agonists like semaglutide, melanocortin receptor agonists like PT-141, and growth hormone secretagogue receptor agonists like ipamorelin.