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IUPAC name 7-methoxy-1-methyl
CAS number 304-21-2
Molecular formula C13H14N2O[1]
Molar mass 214.263 g/mol[1]
Melting point

232–234 °C[2]

Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

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.


Harmaline is a central nervous system stimulant and a "reversible inhibitor of MAO-A (RIMA)."[3] It being selectively an MAO-A inhibitor means that it only binds to MAO-A and it leaves MAO-B free to metabolize tyrosine-containing foods that can be dangerous with MAO-B inhibitors. The reversibility means that, instead of binding permanently to MAO-A for weeks until the body replaces the MAO-A enzyme molecules, harmaline binds to the MAO-A enzyme for only up to 24 hours until it "reverses" its inhibition by separating from MAO-A. This means that the risk of a hypertensive crisis, a dangerous high blood pressure crisis from eating tyrosine-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]

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

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


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

  • Antileishmanial activity of harmaline and other tryptamine derivatives A. Tudor Evans, Simon L. Croft, Department of Medical Protozoology, London School of Hygiene and Tropical Medicine, Keppel Street, London WCIE 7HT, UK
  • Study Indicating that Harmaline is a Free Radical Scavenger


  1. ^ a b c d PubChem
  2. ^ Data from the Sigma Aldrich Catalog (German)
  3. ^ Edward J. Massaro, Handbook of Neurotoxicology
  4. ^ a b c d 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,-M-D. Vasorelaxant effects of harmine and harmaline extracted from Peganum harmala L. seeds in isolated rat aorta. Pharmacol-Res. 2006 Aug; 54(2): 150-7
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Harmaline". A list of authors is available in Wikipedia.
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