NESS 0327

NESS-0327 is a drug used in scientific research which acts as an extremely potent and selective antagonist of the cannabinoid receptor CB₁. It is much more potent an antagonist, and more selective for the CB₁ receptor over CB₂, than the more commonly used ligand rimonabant, with a K_i at CB₁ of 350fM (i.e. 0.00035nM) and a selectivity of over 60,000x for CB₁ over CB₂. Independently, two other groups have described only modest nanomolar CB₁ affinity for this compound (125nM and 18.4nM). Also unlike rimonabant, NESS-0327 does not appear to act as an inverse agonist at higher doses, instead being a purely neutral antagonist which blocks the CB₁ receptor but does not produce any physiological effect of its own.