The plant known commonly as Chacruna, or scientifically as Psychotria viridis, is a perennial shrub native to the humid, tropical lowlands of the Amazon basin. This member of the coffee family (Rubiaceae) is recognized for its unique chemical composition. For centuries, Indigenous communities have cultivated and utilized the leaves in traditional preparations. This significance stems from the plant’s ability to interact with human neurochemistry, making it a central component in spiritual and healing practices across the region.
Botanical Profile and Native Range
Psychotria viridis thrives as an understory shrub across a wide native range that includes Peru, Brazil, Colombia, and Ecuador, often growing up to five meters tall. As an evergreen species, it is adapted to the filtered light and high humidity found beneath the dense canopy of the Amazon rainforest. The plant is most easily identified by its distinctive leaves, which are dark green, glossy, and elliptic in shape.
The leaves feature a notable characteristic called foveolae, which are tiny pockets found on the underside of the leaf where the secondary veins meet the midrib. These small structures are often used by botanists to distinguish P. viridis from similar species in the large Psychotria genus. The plant’s ability to propagate easily from leaf or stem cuttings has allowed Indigenous groups to cultivate it reliably in their forest gardens.
The Active Compounds
The significance of Psychotria viridis lies in the psychoactive compound concentrated within its leaves: N,N-Dimethyltryptamine, or DMT. As a tryptamine alkaloid, DMT is chemically related to the neurotransmitter serotonin and is present in the dried leaves at concentrations that typically range between 0.1% and 0.6% by mass. Once in the brain, DMT acts primarily by binding to serotonin receptors, particularly the 5-HT2A receptor, which mediates the compound’s profound perceptual and visionary effects.
However, DMT is not orally active on its own because the human body possesses a highly efficient defense mechanism against it. In the digestive system, a powerful enzyme called Monoamine Oxidase A (MAO-A) rapidly metabolizes the DMT. This enzyme quickly converts the compound into inactive metabolites, preventing a significant amount from reaching the bloodstream and crossing the blood-brain barrier. Without a mechanism to bypass this enzymatic breakdown, consuming the leaves alone would produce little to no effect.
Ethnobotanical Role in Traditional Brews
The use of Chacruna by Amazonian groups is centered on its role as a necessary ingredient in the ceremonial decoction known as Ayahuasca. Traditional healers understood the chemical barrier to DMT’s activity and solved it by combining the leaves with another specific plant, the vine Banisteriopsis caapi. This vine contains a separate group of compounds called harmala alkaloids, which include harmine, harmaline, and tetrahydroharmine.
These harmala alkaloids function as Monoamine Oxidase Inhibitors (MAOIs) that temporarily deactivate the MAO-A enzyme in the gut. By inhibiting the enzyme’s activity, the MAOIs allow the DMT from the Chacruna leaves to survive the digestive process, enter the bloodstream, and travel to the central nervous system. This synergistic interaction is what makes the Ayahuasca brew orally active, with the effects lasting for several hours.
The preparation of Ayahuasca is a meticulous, multi-day process involving the maceration and prolonged boiling of the B. caapi vine and the P. viridis leaves. This process is often a ritual itself, accompanied by specific prayers and intentions, and is conducted by a trained shaman or curandero. The resulting brew is used in ceremonial contexts for healing, divination, and spiritual insight, with the plant often revered as a “plant teacher.” Indigenous traditions also emphasize a strict preparatory diet, or dieta, involving abstinence from certain foods and activities, which is believed to enhance the spiritual and physical cleansing aspects of the experience.
Legal Status and Conservation
The legal status of Psychotria viridis and its preparations is complex and varies significantly across international borders, largely due to the presence of DMT. Under the 1971 United Nations Convention on Psychotropic Substances, DMT is classified as a Schedule I controlled substance, which has formed the basis for its prohibition in many countries. However, the Convention explicitly states that plants containing controlled substances are not themselves subject to international control, creating a legal gray area for the raw Chacruna plant.
In the United States, the plant itself is not scheduled, but the final Ayahuasca brew that contains the Schedule I compound DMT is generally prohibited. This legal complexity has been challenged by religious organizations, most notably the União do Vegetal (UDV) and Santo Daime, which have successfully secured limited exemptions for the sacramental use of the brew in their religious ceremonies. These court decisions recognize the traditional and religious context of the use, but they do not extend to the general public.
Increased global interest and demand for Ayahuasca have raised concerns about the ecological impact and sustainability of wild harvesting for both P. viridis and B. caapi. Fortunately, P. viridis is categorized as “Least Concern” by the IUCN, and it is relatively easy to cultivate. Many of the religious and retreat centers that utilize the plant now cultivate it in managed forest gardens, often using traditional agroforestry systems. This cultivation method ensures a more reliable and sustainable supply and helps preserve the genetic diversity and traditional knowledge surrounding the plant.