A chemical that binds to a receptor and increases its activity. Agonists are classified by the way they interact with their receptor. There are direct (orthosteric) agonists, indirect (allosteric) agonists, and biased agonists, for example.
A chemical that binds to a receptor and increases its activity.
Summary from Wikipedia:
An agonist is a chemical that binds to a receptor and activates the receptor to produce a biological response. Whereas an agonist causes an action, an antagonist blocks the action of the agonist, and an inverse agonist causes an action opposite to that of the agonist.Read more