Amazon, Botany, Indigenous Worlds
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When and how was Ayahuasca discovered by the world outside the Amazon?

History of ethnobotanical research

The earliest Europeans to mention Ayahuasca were Jesuits travelling in the Amazon. One of the earliest such reports of this “diabolical potion,” written in 1737, describes it as: “an intoxicating potion ingested for divinatory and other purposes and called ayahuasca, which deprives one of his senses and, at times, of his life.”

Several early explorers of northwestern South America also referred to ayahuasca, yage and caapi. They all cited a forest liana but offered little detail.

The serious scientific study of ayahuasca began in the 1850s with the field investigations of the English botanist Richard Spruce, a one time British schoolteacher who was among the early explorers to make the perilous journey into the Amazon. Spruce almost died of dysentery and malaria but survived to become one of botany’s greatest collectors. In 1851, while exploring the upper Rio Negro of the Brazilian Amazon, he observed the use of yage among the Tukano Indians of the Rio Uapes in Brasil. He collected samples of Banisteriopsis and sent them home for chemical analysis. He came upon it twice in Peru in 1853. Seven years later, Spruce again encountered the same liana in use among the Guahibo Indians on the upper Orinoco of Colombia and Venezuela, and, later the same year, found it used the Záparo Indians in Peru near the Ecuador border. In his Notes of a Botanist on the Amazon and Andes, he described its sources, its preparation and its effects upon himself.

Spruce suspected that additives were responsible for the psychoactivity of this beverage, although he noted that Banisteriopsis by itself was considered active. The samples he sent to England for chemical analysis were not located and assayed until more than a century later. They were still psychoactive when examined in 1966.

One of Spruce’s greatest contributions was his precise identification of the source of caapi as a new species of the Malpighiaceae. The species was described and called Banisteria Caapi. Subsequent botanical studies showed showed that it belonged to not to the genus Banisteria but to the allied genus Banisteriopsis. The correct name now is, accordingly, Banisteriopsis Caapi.

Although Spruce’s discovery predates any other published accounts, it was not published until 1873, when it was mentioned in a popular account of his Amazon explorations, and his notes were not published in full until 1908. Credit for the earliest published reports of Ayahuasca usage belongs to the Ecuadorian geographer Manuel Villavicencio, who in 1858 wrote of the use of Ayahuasca in sorcery and divination on the upper Rio Napo. The experience made him feel he was “flying” to most marvelous places. He reported that natives using this drink were able “to foresee and answer accurately in difficult cases, be it to reply opportunely to ambassadors from other tribes in a question of war; to decipher plans of the enemy through the medium of this magic drink and take proper steps for attack and defense; to ascertain, when a relative is sick, what sorcerer has put on the hex to carry out a friendly visit to other tribes to welcome foreign travelers or, at least to make sure of the love of their womenfolk.”

In the early twentieth century, it was learned that the use of Banisteriopsis vines for healing, initiatory and shamanic rites extended from Colombia to the Amazon of Peru and Bolivia and even to the rain-forested Pacific coastal region of Colombia and Ecuador.

Throughout the remainder of the 19th century, various ethnographers and explorers continued to report on their encounters of the use of an intoxicating beverage prepared by various indigenous Amazonian tribes, and purportedly prepared from the “roots” of various “shrubs” or “lianas.” They rarely collected specimens of the plants they observed. But the fact that diverse admixtures were being used was established.

In 1939 it was established that caapi, yagé, and ayahuasca were all different names for the same beverage, and that their source plant was identical: Banisteriopsis caapi or B. inebriens.

In 1905 an alkaloid named “telepathine” was obtained from unvouchered botanical material called “yajé” In 1923, an alkaloid was again isolated from unvouchered botanical materials and again named telepathine; another Colombian team isolated an alkaloid which they called yageine.

Between 1926 and 1928, several different scientists isolated an alkaloid from the B. caapi vine, which they variously named yageine, telepathine and banisterine. These were all shown to be the same alkaloid and to be identical with harmine, which had been isolated from (and named for) Peganum harmala in 1847. Samples of “banisterine” were used in a clinical study of 15 post-encephalitic Parkinson’s patients, with dramatic positive effects reported. This was the first time that a reversible MAO inhibitor had been review for the treatment of Parkinson’s Disease, though harmine’s activity as a reversible MAOI was not discovered until nearly 30 years later. This represents one of the few instances where a hallucinogenic drug has been clinically evaluated for the treatment of any disease.

From 1941 to 1953, Richard Evans Schultes explored the Amazon (especially the Colombian Amazon), researching the plant knowledge of Amazonian peoples. Schultes, later a professor at Harvard and author of many books, is regarded as the “father of modern ethnobotany.” He documented the use of over 2,000 medicinal plants in the Amazon, and dozens of species are named for him. He observed the use importance of Ayahuasca in indigenous cultures throughout the Upper Amazon. He recorded the fact that admixture plants varied widely, but observed the B. caapi vine or a close relative was the one constant in the brews.

In 1957 harmine, harmaline, and tetrahydroharmine were isolated from the B. Caapi vine. By 1965, the active alkaloids of Banisteriopsis caapi and related species were firmly established as harmine, tetrahydroharmine, and harmaline.

In the late 1960’s, the first detailed reports began to emerge of the use of admixtures as a frequent component of the brew. At least two of these admixtures, Diplopterys cabrerana (then called Banisteriopsis rusbyana) and Psychotria species, particularly P. viridis, were often added to the brew to “strengthen and extend” the visions.

A further surprise came when the alkaloid obtained from these species proved to be the potent short-acting (but orally inactive) hallucinogen N,N-dimethyltryptamine (DMT).

DMT had been known as synthetic since 1931, but its occurrence in nature and its hallucinogenic properties had only come to light in 1955, when it was established as the active ingredient in the hallucinogenic snuff Anadenanthera peregrina, used by Indians of the Caribbean and the Orinoco basin of South America. In 1957, the first reports were published of DMT’s profound, though short-lasting, hallucinogenic effect on humans, and of the fact that DMT was orally inactive.

In 1958, it was demonstrated that ß-carbolines were potent, reversible inhibitors of MAO, and it was suggested that Ayahuasca depended for its activity on a synergistic interaction between the MAO-inhibiting ß-carbolines in Banisteriopsis with the psychoactive but peripherally inactivated tryptamine. By the late 1960s, this was confirmed. Until then, the prevailing assumption had been that the psychoactivity of Ayahuasca was due primarily if not entirely to the ß-carbolines.

Schultes and his students Pinkley and der Marderosian published their initial findings on the DMT-containing admixture plants in 1968 and 1969, fueling speculation that DMT, orally activated by ß-carbolines, was responsible for much of the activity of the brew. This notion, although plausible, would not be scientifically confirmed for another decade.

In 1972, Rivier and Lindgren (1972) published one of the first interdisciplinary papers on ayahuasca, reporting on the alkaloid profiles of ayahuasca brews and source plants collected among the Shuar people of the upper Rio Purús in Peru. It discussed numerous admixture plants besides the Psychotria species and Diplopteris cabrerana, and for the first time provided evidence indicating that Ayahuasca admixture technology was complex, and that many species were on occasion used as admixtures.

In 1984, McKenna et al., published the results of their chemical, ethnobotanical, and pharmacological investigations which confirmed the theory that the active principle of Ayahuasca was DMT, rendered orally active by ß-carboline-mediated blockade of peripheral MAO. Experiments on rats showed that the brews were extremely potent MAO inhibitors even when diluted many orders of magnitude; in other words, the B. caapi content of typical brews in the Amazon was orders of magnitude stronger than what was necessary to potentiate the DMT.

In the 1980s, Luis Eduardo Luna began working among mestizo ayahuasqueros near the cities of Iquitos and Pucallpa in Peru. Luna was the first to articulate the importance of the strict diet followed by apprentice shamans, as well as the specific uses of some of the more unusual admixture plants . He was also the first to report on the concept of “plant teachers,” (plantas que enseñan), which is how many of the admixture plants are viewed by the mestizo ayahuasqueros.

Note: this article draws from a number of sources [citations] but primarily from “Ayahuasca: An Ethnopharmacologic History” by Dennis McKenna

© 1998 Dennis J. McKenna, Ph.D. For full citations, names of the scientists who made discoveries, more details, and publication information for their research, see that article, which may be found at

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