Pharmahuasca is a pharmaceutical version of ayahuasca, a psychoactive decoction used by indigenous cultures in South America as part of traditional medicine and shamanism. Traditional ayahuasca is made by brewing the monoamine oxidase inhibitor (MAOI)-containing Banisteriopsis caapi vine with a dimethyltryptamine (DMT)-containing plant, such as Psychotria viridis. Pharmahuasca refers to a similar combination that uses a synthetically produced or pharmaceutical MAOI, such as moclobemide, instead of a plant.
DMT and harmaline or harmine are typically used as components of pharmahuasca. One study tested a formulation of 100 mg buccal harmine with 100 mg intranasal DMT, which produced an effect lasting 2 to 3hours. As a rule, the fewer the ò-carbolines, the less nausea; the more DMT, the more spectacular the visions. The constituents are put into separate gelatin capsules. The capsules with harmaline/harmine are swallowed first and the capsules containing DMT are taken 15 to 20 minutes later. A synthetic MAOI can be used in place of harmaline and harmine, although caution must be taken when choosing an MAOI. The use of moclobemide, a reversible inhibitor of monoamine oxidase-A (RIMA), has been recorded and is safer than older irreversible MAOIs (such as isocarboxazid) due to its significantly shorter and more selective effects (although it still exhibits a wide range of dangerous drug-drug interactions).