agonist

noun

ag·​o·​nist ˈa-gə-nist 

1

: one that is engaged in a struggle

2

[from antagonist]

a

: a muscle that is controlled by the action of an antagonist with which it is paired

b

: a chemical substance capable of combining with a specific receptor on a cell and initiating the same reaction or activity typically produced by the binding endogenous substance

dopaminergic agonists

compare antagonist sense 2b

Examples of agonist in a Sentence

Recent Examples on the Web

The family of medications called GLP-1 receptor agonists includes drugs like Wegovy, Zepbound, Ozempic, Mounjaro and Victoza. —Brenda Goodman, CNN Money, 9 Apr. 2025

The company’s medicines targeting obesity have gotten attention recently amid the public’s demand for injectable glucagon-like peptide 1 (GLP-1) agonists, some more commonly known as Ozempic and Wegovy. —Natallie Rocha, San Diego Union-Tribune, 25 Mar. 2025

Viking Therapeutics is developing a once-daily oral dual GLP-1/GIP receptor agonist. —Annika Kim Constantino, CNBC, 24 Mar. 2025

The entrance of more GLP-1 agonists into the market, especially generic ones, could eventually bring prices down. —Bruce Y. Lee, Forbes, 21 Mar. 2025

Word History

Etymology

borrowed from Late Latin agōnista, borrowed from Greek agōnistḗs, from agōnízesthai "to contend, fight" + -istēs -ist entry 1 — more at agonize

First Known Use

1658, in the meaning defined at sense 1

Rhymes for agonist

• antagonist
• protagonist

Medical Definition

agonist

noun

ag·​o·​nist ˈag-ə-nəst 

1

: a muscle that on contracting is automatically checked and controlled by the opposing simultaneous contraction of another muscle

called also agonist muscle, prime mover

compare antagonist sense a, synergist sense 2

2

: a chemical substance (as a drug) capable of combining with a receptor on a cell and initiating the same reaction or activity typically produced by the binding of an endogenous substance

binding of adrenergic agonists

compare antagonist sense b