From Wikipedia, the free encyclopedia
(R)-Tetrahydroharmine Structural Formula V.1.svg
Clinical data
Other namesTHH; 1,2,3,4-Tetrahydroharmine; Leptaflorine; 2,3,4,9-Tetrahydro-7-methoxy-1-methyl-1H-pyrido(3,4-b)indole
Legal status
Legal status
  • AU: S9 (Prohibited substance)
  • 7-methoxy-1-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole
CAS Number
PubChem CID
Chemical and physical data
Molar mass216.284 g·mol−1
3D model (JSmol)
  • CC1C2=C(CCN1)C3=C(N2)C=C(C=C3)OC
  • InChI=1S/C13H16N2O/c1-8-13-11(5-6-14-8)10-4-3-9(16-2)7-12(10)15-13/h3-4,7-8,14-15H,5-6H2,1-2H3

Tetrahydroharmine (THH) is a fluorescent indole alkaloid that occurs in the tropical liana species Banisteriopsis caapi.[1]

THH, like other harmala alkaloids in B. caapi, namely harmaline and harmine, is a reversible inhibitor of monoamine oxidase A (RIMA),[2] but it also inhibits the reuptake of serotonin.[3]

THH contributes to B. caapi's psychoactivity as a serotonin reuptake inhibitor.[4]

Legal Status[edit]


Harmala alkaloids are considered Schedule 9 prohibited substances under the Poisons Standard (October 2015).[5] A Schedule 9 substance is a substance which may be abused or misused, the manufacture, possession, sale or use of which should be prohibited by law except when required for medical or scientific research, or for analytical, teaching or training purposes with approval of Commonwealth and/or State or Territory Health Authorities.[5]

See also[edit]


  1. ^ Callaway JC (June 2005). "Various alkaloid profiles in decoctions of Banisteriopsis caapi". Journal of Psychoactive Drugs. 37 (2): 151–155. doi:10.1080/02791072.2005.10399796. PMID 16149328. S2CID 1420203.
  2. ^ Buckholtz NS, Boggan WO (November 1977). "Monoamine oxidase inhibition in brain and liver produced by beta-carbolines: structure-activity relationships and substrate specificity". Biochemical Pharmacology. Elsevier BV. 26 (21): 1991–1996. doi:10.1016/0006-2952(77)90007-7. PMID 921812.
  3. ^ Morales-García JA, de la Fuente Revenga M, Alonso-Gil S, Rodríguez-Franco MI, Feilding A, Perez-Castillo A, Riba J (July 2017). "The alkaloids of Banisteriopsis caapi, the plant source of the Amazonian hallucinogen Ayahuasca, stimulate adult neurogenesis in vitro". Scientific Reports. Springer Science and Business Media LLC. 7 (1): 5309. doi:10.1038/s41598-017-05407-9. PMID 28706205.
  4. ^ Callaway JC, McKenna DJ, Grob CS, Brito GS, Raymon LP, Poland RE, et al. (June 1999). "Pharmacokinetics of Hoasca alkaloids in healthy humans". Journal of Ethnopharmacology. 65 (3): 243–256. doi:10.1016/S0378-8741(98)00168-8. PMID 10404423.
  5. ^ a b "Poisons Standard October 2015". Australian Government Department of Health. September 2015.

Further reading[edit]