In a double-blind, placebo-controlled study over a 3-day meditation retreat, 40 experienced meditators received either DMT-harmine or a placebo. Those who took DMT-harmine reported greater mystical-type experiences, non-dual awareness, and emotional breakthrough during the acute substance effects, and greater psychological insight one day later after adjusting for baseline differences. Mindfulness and compassion did not differ significantly between groups. At one-month follow-up, the DMT-harmine group rated their experience as more personally meaningful, spiritually significant, and well-being-enhancing than the placebo group. The findings suggest specific synergistic effects of DMT-harmine during meditation.
Ayahuasca contains DMT and harmine, but their interactions are not fully understood. In a single-blind, randomized, two-arm, factorial dose-finding study with 16 healthy participants, each received six dose combinations of DMT (0-120 mg) and harmine (0-180 mg) via a transmucosal delivery system. All combinations produced dose-dependent subjective effects lasting 4-5 hours, with peak DMT and harmine levels reaching 33 ng/mL and 49 ng/mL, respectively. The interaction was bidirectional: harmine reduced DMT metabolism, while DMT altered harmine pharmacokinetics. The formulation had a favorable safety profile, supporting further testing for affective disorders.