High affinity histamine H3 receptor ligand (pKi = 8.62) that acts as a protean agonist at recombinant and native receptors. In functional studies, activity ranges from full agonist to inverse agonist depending on system used. Displays partial agonist effects on cAMP inhibition and MAPK activity, neutral antagonist activity on histamine release and partial inverse agonism of [3H]-arachidonic acid release. Purity 98%. MW (observed): 306.32