Harmaline

Harmaline, also known as 7-methoxyharmalan or as 3,4-dihydro-7-methoxy-1-methyl-β-carboline, is a harmala alkaloid and β-carboline which has hallucinogenic effects and monoamine oxidase inhibitor (MAOI) activity. It is the partly hydrogenated form of harmine.

Plants containing harmaline are combined in ayahuasca to inhibit monoamine oxidase (MAO), allowing orally consumed dimethyltryptamine (DMT) to become orally active and produce psychoactive effects. Harmala alkaloids, including harmaline, are psychoactive on their own in humans, with harmaline being particularly hallucinogenic, although other compounds such as harmine and tetrahydroharmine (THH) have also been reported to produce hallucinogenic effects as well.

Harmaline is present in Peganum harmala (Syrian rue). Syrian rue seeds contain about 3% harmala alkaloids by dry weight. Harmaline was first isolated from plants in 1841, its chemical structure identified in 1919, and it was first synthesized in 1927.