The mechanism{2} by which a pharmacologically active substance produces an effect on a living organism or in a biochemical system; as, the mechanism of action of actinomycin involves its binding to DNA. The mechanism of action is usually considered to include an identification of the specific molecular targets to which a pharmacologically active substance binds or whose biochemical action it influences; a general recognition of the broad biochemical pathways (such as DNA synthesis, protein synthesis, cholesterol synthesis) which are inhibited or affected by a substance is termed its mode of action.

Used to describe the ways pharmacologic agents achieve their effects

The way by which a procedure or product works to produce an intended effect.

The fundamental physical or chemical processes involved in or responsible for an action or reaction.

How a drug or physical process works in the body.