Pharmahuasca: Human Pharmacology of Oral DMT Plus Harmine
Journal of Psychoactive Drugs April 1, 1999 DOI: 10.1080/02791072.1999.10471741 via OpenAlex
Summary
AI-generated from the abstractEight self-experimenters confirmed the 1967 Holmstedt-Lindgren hypothesis: oral N,N-dimethyltryptamine (DMT) becomes psychoactive when ingested alongside beta-carbolines like harmine because the beta-carbolines inhibit monoamine oxidase (MAO). The report summarizes roughly 70 bioassays of pharmahuasca—capsules containing crystalline DMT plus harmine, and other tryptamine–beta-carboline combinations—and reviews the relevant literature. The findings support the mechanism underlying the ayahuasca effect, where MAO inhibition enables DMT's oral activity.
Study at a glance
| Characteristics | Review Peer reviewed |
|---|---|
| Sample size | 8 |
| Population | Human self-experimenters |
| Topics | Ayahuasca |
| Keywords | Harmine Tryptamines Hallucinogen Pharmacology |
| Citations | 136 |
| Key finding | The Holmstedt-Lindgren hypothesis—that oral DMT is psychoactive due to MAO inhibition from co-ingested beta-carbolines—was confirmed by eight self-experimenters across roughly 70 bioassays. |
Abstract
A summary is presented of human self-experiments or psychonautic bioassays of pharmahuasca--capsules containing crystalline N,N-dimethyltryptamine (DMT) plus harmine, as well as combinations of other psychoactive tryptamines with other beta-carbolines. The 1967 Holmstedt-Lindgren hypothesis of the ayahuasca effect--oral psychoactivity of DMT consequent to monoamine-oxidase (MAO) inhibition from simultaneous ingestion of beta-carbolines--has been confirmed by eight self-experimenters. Results of a total of some 70 bioassays are summarized and the literature on this subject is reviewed (with 66 references and one table).