N-Methylanhalinine, also known as O-methylanhalidine, is a tetrahydroisoquinoline alkaloid found in various Turbinicarpus cactus species. It has been found to act as a potent inverse agonist of the serotonin 5-HT<sub>7</sub> receptor. The compound is several-fold more potent as a serotonin 5-HT<sub>7</sub> receptor inverse agonist than its parent compound anhalinine.