N-Arachidonoylserotonin (Arachidonyl serotonin; AA-5-HT) is a potent fatty acid amide hydrolase (FAAH) inhibitor with an IC50 value of 1~12 µM. N-Arachidonoylserotonin acts also as an antagonist of transient receptor potential vanilloid-type 1 (TRPV1) channels (IC50=70~100 nM) . N-Arachidonoylserotonin is analgesic in rodents [1].