A method for identifying test substances that selectively inhibit or activate only a restricted number of transduction pathways of a G-protein-coupled receptor (GPCR) the method comprising the steps of: a) selecting at least one test compound; b) exposing a cell culture, preferably a mammalian cell culture, to the test compound and incubating the culture under suitable conditions; c) selecting at least two distinct intracellular events which are controlled, at least partially, by the G-protein-coupled receptor; d) testing for the ability of said test compound to modulate one of the selected intracellular event; and selecting the test compound which selectively modulates at least one of the pre-selected intracellular event and does not modulate at least another preselected intracellular event.
