Harmaline (HL)

Harmaline is a fluorescent psychoactive indole alkaloid from the group of harmala alkaloids and beta-carbolines. It is the reduced hydrogenated form of harmine. Harmaline is a central nervous system stimulant and a "reversible inhibitor of MAO-A (RIMA)". This means that the risk of a hypertensive crisis, a dangerous high blood pressure crisis from eating tyramine-rich foods such as cheese, is likely lower with harmaline than with irreversible MAOIs such as phenelzine. The harmala alkaloids are psychoactive in humans. Harmaline is shown to act as an acetylcholinesterase inhibitor. Harmaline also stimulates striatal dopamine release in rat at very high dose levels. Since harmaline is a reversible inhibitor of monoamine oxidase A, it could, in theory, induce both serotonin syndrome and hypertensive crises in combination with serotonergic and catecholaminergic drugs respectively.