Lu AA-33810 is a drug developed by Lundbeck, which acts as a potent and highly selective antagonist for the neuropeptide Y receptor Y<sub>5</sub>, with a Ki of 1.5nM and around 3300x selectivity over the related Y<sub>1</sub>, Y<sub>2</sub> and Y<sub>4</sub> receptors. In animal studies it produced anorectic, antidepressant and anxiolytic effects, and further research is now being conducted into its possible medical application in the treatment of eating disorders.