Harmaline

As a reversible MAO-A inhibitor, harmaline shares the interaction dangers of that class, and combining it with SSRIs, other serotonergic drugs, other MAO inhibitors, or tyramine-rich foods can trigger serotonin syndrome or hypertensive reactions. Even without such combinations it commonly produces nausea, vomiting, dizziness, and its hallmark tremor, and higher doses can cause pronounced neuromuscular and cardiovascular effects. Its tremorgenic and serotonergic actions make it unsuitable for anyone with neurological or cardiovascular conditions or on interacting medication. Not medical advice.

Harmaline is a psychoactive beta-carboline indole alkaloid, the dihydro (reduced) counterpart of harmine, and it was first isolated from the seeds of Syrian rue (Peganum harmala) in the 1840s, with early synthetic work by Hasenfratz reported around 1930. Peganum harmala had long been used across Central Asia, Persia, and the Middle East as a folk medicine and dye source, while in the Amazon the same class of alkaloids occurs in the vine Banisteriopsis caapi, the monoamine-oxidase-inhibiting component of the ayahuasca brew.

In the early twentieth century researchers isolating alkaloids from Banisteriopsis briefly named the active principle "telepathine" and "banisterine" before it was recognized as identical to the harmala alkaloids already known from Syrian rue; Chen and Chen confirmed harmine's presence in authenticated B. caapi in 1939. Harmaline and harmine were investigated in the early twentieth century, including trials of banisterine for post-encephalitic Parkinsonism. Harmaline remains largely a research chemical and a constituent of traditional botanical preparations rather than an approved drug.