Harmaline is a fluorescent psychoactive indole alkaloid from the group of harmala alkaloids and beta-carbolines. It is the reduced hydrated form of harmine.

Occurrence in nature

Various plants contain harmaline including Banisteriopsis caapi (a jungle vine) and Peganum harmala (Syrian Rue) as well as the hallucinogenic drink ayahuasca, which is traditionally brewed using Banisteriopsis caapi. Also passionflower (Passiflora incarnata) and tobacco.[1]


Harmaline is a central nervous system stimulant and a "reversible inhibitor of MAO-A (RIMA)."[2] It being a reversible MAO-A inhibitor means that it competes with tyramine for binding to MAO-A, so foods containing some tyramine can be safely consumed (wine and aged cheese should probably be avoided for twelve hours prior to consuming harmaline containing plants). The reversibility means that, instead of binding permanently to MAO-A for weeks until the body replaces the MAO-A enzyme molecules, harmaline binds only transiently, so tyramine can be metabolized as well by competing with harmaline for the binding site on the enzyme.[3] This means that the risk of a hypertensive crisis, a dangerous high blood pressure crisis from eating tyramine-rich foods such as cheese, is potentially lower with harmaline than with non-reversible MAOI's, especially after 24 hours following ingestion.

Depending upon the dosage, harmaline induces temporary oneirophrenia and ataxia. Harmaline, on the higher end of its safe dosage range, has hallucinogenic properties, but it differentiates itself significantly from the "classical" hallucinogens in its pharmacology. Since harmaline is a reversible monoamine oxidase inhibitor, it could increase the effect of some drugs problematically. Harmaline causes no known physical or psychological dependence.

United States Patent Number 5591738 describes a method for treating various chemical dependencies via the administration of harmaline and or other beta-carbolines.[4]

Claudio Naranjo has studied potential applications of harmal alkaloids in psychotherapy.

Harmaline has also been shown to induce "vasorelaxant effects" in "isolated rat aorta."[5]

Harmaline has both protective and toxic effects on neurons.[4]

Harmaline is known to act as a histamine N-methyltransferase inhibitor.


In the year 1841 harmaline was isolated from Peganum harmala by Goegel.[4] It was first synthesized in 1930 by Hasenfratz.[4]


  2. Massaro, Edward J. (2002). Handbook of neurotoxicology. Totowa, NJ: Humana Press. p. 237. ISBN 0-89603-796-7. 
  3. Youdim MB, Weinstock M (January 2004). "Therapeutic applications of selective and non-selective inhibitors of monoamine oxidase A and B that do not cause significant tyramine potentiation". Neurotoxicology 25 (1-2): 243–50. 
  4. 4.0 4.1 4.2 4.3 Method of treating chemical dependency using .beta.-carboline alkaloids, derivatives and salts thereof
  5. Berrougui H, Martin-Cordero C, Khalil A, Hmamouchi M, Ettaib A, Marhuenda E, Herrera MD (August 2006). "Vasorelaxant effects of harmine and harmaline extracted from Peganum harmala L. seeds in isolated rat aorta". Pharmacol Res. 54 (2): 150–7. 

External links

This page uses content from the English Wikipedia. The original article was at Harmaline. The list of authors can be seen in the page history.

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