WAY-163,909 is a drug which acts as a potent and reasonably selective agonist for the serotonin 5-HT<sub>2C</sub> receptor. It has antipsychotic-like effects in animal models, and has been used to study the role of the 5-HT<sub>2C</sub> receptor subtype in the action of addictive drugs such as nicotine and methamphetamine.