agonist
n.n. a substance that causes a specific reaction in the body, like a drug that makes a muscle move or a heart beat faster.
n. a substance that binds to a receptor and triggers a biological response, typically mimicking the action of a naturally occurring neurotransmitter or hormone.
The drug acts as an agonist for the brain's pain receptors.
Researchers are developing a selective agonist that targets only the receptors responsible for reducing inflammation without affecting other parts of the nervous system.
In pharmacology, an agonist differs from an antagonist by its ability to activate a receptor, whereas an antagonist merely blocks the receptor from being activated by other substances.
Borrowed from Latin agōnista, from Ancient Greek ἀγωνιστής (agōnistḗs, “combatant, champion”). By surface analysis, agon or agony + -ist.