Intrinsic activity is typically measured using in vitro assays that evaluate the biological response induced by a substance when it binds to its target receptor. The response is compared to that of a full agonist, which has a defined intrinsic activity of 1.0. Partial agonists have intrinsic activity values between 0 and 1, while antagonists have an intrinsic activity of 0 as they do not activate the receptor.
