N-Arachidonoyl dopamine-d8 is intended for use as an internal standard for the quantification of N-arachidonoyl dopamine by GC- or LC-MS. Several different arachidonoyl amino acids, including NADA, have been isolated and characterized from bovine brain.¹ NADA is the amide of the neurotransmitter dopamine and arachidonic acid. NADA is a CB1-selective cannabinoid agonist, inducing the typical tetrad of hypothermia, analgesia, catalepsy, and hypomotility in rats which exceeds that of anandamide (AEA).² NADA is a full agonist at the vanilloid receptor 1, but is inactive on the dopaminergic D1 and D2 receptors. NADA is also a potent inhibitor (IC50 = 0.25 µM) of the proliferation of MCF-7 breast carcinoma cells. Recent reports of NADA’s endothelium-dependent vasodilation indicate that some of its cannabinergic activities antagonized by SR141716A may be non-CB1/CB2 dependent.³