SB-243213 is a research chemical which acts as a selective inverse agonist for the 5HT<sub>2C</sub> receptor and has anxiolytic effects. It has better than 100x selectivity for 5-HT<sub>2C</sub> over all other receptor subtypes tested, and a longer duration of action compared to older 5-HT<sub>2C</sub> antagonist ligands.