CGRP is primarily produced in nervous tissue, however, its receptors are expressed throughout the body. CGRP is also strongly implicated in the vasodilatory effect of endogenous cannabinoid anandamide in the brain. This effect was found to be antagonised by capsazepine. CGRP is also currently a major target of research in regards to factors effecting the onset of migraine headaches. Merck has announced promising results in Phase III trials with Telcagepant, a CGRP antagonist.