harmine

Harmine is a naturally occurring beta-carboline alkaloid, chemically described as 7-hydroxy-1-methyl-9H-pyrido[3,4-b]indole. It occurs in several plant species, most notably in the seeds of Peganum harmala (Syrian rue) and in the leaves of Banisteriopsis caapi, a key component of ayahuasca preparations. Along with harmaline and tetrahydroharmine, harmine is one of the major harmala alkaloids that contribute to the pharmacological effects of these brews.

Chemically, harmine is a planar indole-based heterocycle with a hydroxy group at position 7 and a methyl group at the N-1 position. In plants, it is biosynthesized from tryptophan-derived pathways as part of the secondary metabolite repertoire.

Pharmacologically, harmine is best known as a reversible inhibitor of monoamine oxidase A (RIMA). In ayahasca, MAO-A inhibition allows orally administered DMT to reach the brain, producing psychedelic effects. Harmine and related beta-carbolines may also contribute to antidepressant-like activity in preclinical studies and interact with other neurotransmitter systems.

Historically, harmine has been used in traditional medicine and as a constituent of ayahuasca brews for ritual and therapeutic contexts. In modern pharmacology, it is studied for its MAOI properties and its potential to modulate mood and cognition, but it can cause adverse reactions when combined with serotonergic drugs or tyramine-containing foods.

Legally, harmine’s status varies by jurisdiction. As a chemical with MAO-inhibiting activity, it is regulated in some countries and can be a controlled substance precursor in others, while in many places it is not scheduled but may occur in plant materials that are regulated.