N-Desmethyl Pimavanserin is the active metabolite of Pimavanserin. Pimavanserin is a selective inverse agonist of the 5-HT2A receptor with pIC 50 and pK d of 8.73 and 9.3, respectively. In Vitro The mean plasma half-lives for Pimavanserin and its metabolite N-Desmethyl Pimavanserin (AC-279) are 57 hours and 200 hours, respectively. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Form:Solid