Human multidrug and toxic compounds extrusion transporter 1 (hMATE1/ SLC47A1 ) is a H⁺-coupled organic cation exporter responsible for the final step of excretion of various xenobiotics at the kidney and liver. In this study, effects of dietary constituents on hMATE1 mediated drug transport were examined to evaluate possible food–drug interactions. Bergamottin inhibited hMATE1 mediated tetraethyl ammonium transport activity, with a K _i of 98.7 µ M . Coumarins, flavonols, and catechin inhibited hMATE1 activity. Among 23 compounds tested, isorhamnetin was the strongest inhibitor of hMATE1 with the K _i of 0.32 µ M in a competitive manner. Since isorhamnetin is abundant in Ginkgo biloba that is widely used for herbal supplements, the findings suggest the potential hMATE1 related food–drug interactions.