Overcoming epistemic injustices in the biomedical study of ayahuasca: Towards ethical and sustainable regulation

This commentary (2022) questions the epistemic authority of western science and medicine in over 30 years of research on ayahuasca. Ayahuasca has long been used by indigenous peoples in countries like Brazil, Peru and Colombia, and the researchers propose new approaches to maintain epistemically fair research and ensure these peoples traditional knowledge and biocultural heritage is maintained. Without adequate regulation, the rights of indigenous people, as well as the sustainability of the Amazon itself, face threat.


“After decades of biomedical research on ayahuasca’s molecular compounds and their physiological effects, recent clinical trials show evidence of therapeutic potential for depression. However, indigenous peoples have been using ayahuasca therapeutically for a very long time, and thus we question the epistemic authority attributed to scientific studies, proposing that epistemic injustices were committed with practical, cultural, social, and legal consequences. We question epistemic authority based on the double-blind design, the molecularization discourse, and contextual issues about safety. We propose a new approach to foster epistemically fair research, outlining how to enforce indigenous rights, considering the Brazilian, Peruvian, and Colombian cases. Indigenous peoples have the right to maintain, control, protect, and develop their biocultural heritage, traditional knowledge, and cultural expressions, including traditional medicine practices. New regulations about ayahuasca must respect the free, prior, and informed consent of indigenous peoples according to the International Labor Organization Indigenous and Tribal Peoples Convention no. 169. The declaration of the ayahuasca complex as a national cultural heritage may prevent patenting from third parties, fostering the development of traditional medicine. When involving isolated compounds derived from traditional knowledge, benefit-sharing agreements are mandatory according to the United Nations’ Convention on Biological Diversity. Considering the extremely high demand to treat millions of depressed patients, the medicalization of ayahuasca without adequate regulation respectful of indigenous rights can be detrimental to indigenous peoples and their management of local environments, potentially harming the sustainability of the plants and of the Amazon itself, which is approaching its dieback tipping point.”

Authors: Eduardo E. Schenberg & Konstantin Gerber


Recent clinical trials show evidence of therapeutic potential for depression, but indigenous peoples have been using ayahuasca therapeutically for a very long time. We propose a new approach to foster epistemically fair research, outlining how to enforce indigenous rights.


Ayahuasca is a word from the Kichwa language that refers to an Amazonian vine and a brew. It is prepared with different recipes including combinations with 90 different potential plant additives, and is used in visionary preparations like Chicha, Cebil, Jurema, and Llampu.

There are several kinds of bamboo vines in the Amazon, including xawan huni (“big red macaw vine”), baka huni (“fish or shadow vine”), and xane huni (“little bird vine”). They are also called ninka wa kawa (“to make hear”).

Huni Kui plants have many different uses, including avoiding roasted meat before ingesting Nixi Pae, which can lead to visions. Nixi Pae songs control the “strength” of traditional medicine, and there are two phases of the Nixi Pae experience.

The Huni Kuin drink NixiPae to experience synesthetic perceptions, which are described by specific cultural concepts such as transformation. The yuxin live in plants and animals that recognize the Huni Kuin as the true people.

Current regulations

During the exploration of the Amazon in the 19th and 20th centuries, ayahuasca became the central sacrament of syncretic Brazilian religions. These practices have since expanded around the world.

During its cultural expansion around the globe, ayahuasca attracted the attention of health committees, medical associations, and drug control departments and agencies. However, traditional brews like ayahuasca are outside of international control according to International Narcotics Control Board Reports of 2010 and 2012.

In Colombia, Yagé has a code of ethics edited by the indigenous medicine yageceros union, and an environmental protection code that includes medicinal plants and the culture of Yagé.

In Peru, the traditional uses of ayahuasca were declared a national cultural heritage, and the Shipibo-Konibo-Xetebo karos (sacred healing songs) were declared national cultural heritage. The therapeutic properties of the plants are recognized as a matter of cultural continuity.

In Brazil, responsible religious use of B. caapi was introduced after a temporary prohibition in 1985. The Brazilian National Drug Policy Council Resolution no. 1 of 2010 consolidated previous decisions on the subject matter.

Biomedical epistemology

Although the Brazilian resolution encouraged biomedical research, it did not outline how such a research program should be conducted. However, many studies followed, notably in Spain.

The foundations and objectives of this biomedical research program were outlined about 10 years later, with the main objectives being to evaluate the “tolerability” of ayahuasca in humans. Pharmacologists considered ayahuasca’s complex mechanism of action, which involves several active ingredients, an “unusual challenge to the pharmacologist”. To overcome this challenge, they proposed a standardization of the brew, which is made exclusively with B. caapi and P. viridis, followed by quantification of active compounds.

Biomedical research still had to employ the gold standard, the double-blind design, to achieve objective assessments of a drug’s safety and efficacy without subjective biases. Therefore, a method for freeze drying and encapsulating ayahuasca samples was developed.

This objective and reductionist biomedical research program with ayahuasca is currently on the rise, with many therapeutic indications under scrutiny. Three publications have reported on the safety and efficacy of ayahuasca administered in psychiatric research settings for patients with depression. If confirmed by future studies with a larger number of participants, ayahuasca can become the first plant medicine treatment in psychiatry. Given the high prevalence of depression, which is estimated to affect 300 million people worldwide by 2030, this Amazonian-based indigenous plant medicine could have significant market potential.

An epistemic injustice

The use of ayahuasca for therapeutic purposes is not new, but has been noted by many scholars since the 19th century. When some Western industrialized nations allowed the religious use of ayahuasca, but postponed the therapeutic, a testimonial epistemic injustice was committed.

As biomedical studies approach the conclusion that ayahuasca and its molecular compounds indeed have therapeutic potentials, the vicious cycle of epistemic injustice tends to break up, revealing the original prejudice of biomedicine.

Consequences of the epistemic injustice for indigenous peoples

The Brazilian regulation of ayahuasca postponed any medicinal use to a future moment when biomedical studies can eventually conclude that ayahuasca indeed has such properties. However, indigenous people already use ayahuasca according to their own therapeutic epistemology.

Indigenous peoples in the Cuenca Amazonica demanded reparation for losses due to a patent, which was nullified in 1999, but a new patent was conferred for the years 2001 to 2003.

Currently, start-ups are developing DMT-based therapies, including a medicalized and controlled version of DMT by Ko and Entheon. DMT was first reported in the chemical literature in 1931, but was first discovered a decade earlier by a Brazilian scientist who worked with the Pancar indigenous people and their Jurema (Ajucá) wine. His nigerine was later identified as being the same as Manske’s DMT. Current attempts to develop DMT through large-scale synthesis for therapeutic purposes should not disrespect indigenous knowledge and rights.

Consequences for biomedical research

Biomedicine has appropriated the ayahuasca brew, its plants, and constituents, at the risk of losing critical and important information with practical, cultural, social, and even legal consequences.

Ayahuasca has been studied for about two decades, but it is doubtful that the standardization of ayahuasca for pharmacological studies was ever achieved. Therefore, biomedicine cannot establish the appropriate preparation method or plant proportions and doses for each disorder.

The biomedical community is blind to the potential of numerous distinct products with different safety profiles and therapeutic properties due to the different proportions of various chemical compounds. This is evident in one trial for depression, where a high DMT concentration was mistaken for a very low one.

The disregard for plant variability and the diversity of preparation methods resulting in the chemical complexity of different ayahuasca samples is another negative epistemic consequence. In ayahuasca studies, the molecularization discourse appears as it does in general biomedical writings, with general disagreement between the three studies. Disregard for patients’ subjective reports and interpretations of their own experiences is common in psychiatry, but can be detrimental to treatment outcomes. Patients’ qualitative reports about ayahuasca treatment for depression revealed issues related to spirituality and the experience of the divine, and it may be the case that including more carefully included accounts of patients’ subjective experiences will improve our understanding of ayahuasca’s therapeutic properties.

Pharmacology attributes its highest epistemic authority to double-blind designs, but the nature of the drug’s effects may unblind subjects and researchers, making it doubtful if objectivity can ever be achieved in such trials. Although unblinding is not a new limitation to the double-blind design, its underreporting became pervasive in pharmacological studies. Thus, it is important to assess if the blind design has been broken or not. Unblinding was not reported in the biomedical literature about ayahuasca for more than a decade, until the only double-blind clinical study with ayahuasca to date. Although it was mentioned that five out of 18 participants in the placebo group misclassified the placebo drink as ayahuasca, the authors did not report the rates of correct guesses in the ayahuasca group or among researchers in the study for both ayahuasca and placebo groups, nor levels of confidence for both patients and researchers.

The epistemic injustice to biomedicine’s own knowledge about ayahuasca as a therapeutic tool involves the issue of vomiting. In early studies, data from participants who vomited were discarded, and the use of antiemetic drugs was suggested, but the possibility that emesis may function as a safety mechanism was ignored.

There is a possibility of developing specific preparations with less harmaline concentration to avoid emesis after ayahuasca intake. Some indigenous and religious cultures consider ayahuasca emesis as part of the effects, while others may find it displeasing. There is some biomedical evidence suggesting that ayahuasca compounds may have anti-parasitic properties, which may explain why some participants report gastrointestinal distress while others do not. Even if it seems unlikely, there is a growing biomedical literature about the impact of the gut microbiome in depression, which echoes testimonies of indigenous peoples about diet being an important factor in the effects of ayahuasca. Epistemic injustice may have negatively impacted on the safety of ayahuasca use in biomedical contexts. Four patients had to stay in the unit for an entire week because of “a more delicate condition”.

Claims that 14% of people attending an ayahuasca ritual required a week of hospitalization seem not to have been critically examined. It is doubtful that biomedical trials would have been approved by ethical review boards if this had been the case in traditional settings.

Overcoming epistemic injustice

In order to advance the understanding of ayahuasca, it is important to critically examine the limits of the standard pharmacological approach, which emphasizes objectivism and reductionism to the detriment of indigenous knowledges.

Ayahuasca research will require biomedicine to leave the clinical research laboratory and go into communities in the forest. Newer technologies make it possible to collect blood, sweat, brain waves, video and audio of entire sessions, in sync with brain data, and collect plant, brew, feces and vomit samples. Designing ayahuasca research together with indigenous cultures would allow the use of a rich variety of ayahuasca preparations, and would offer new insights into the biggest epistemic disagreement in ayahuasca research so far. Subjective reports can be audio recorded, transcribed, and analyzed with techniques from computational psychiatry. MRI and MEG are unlikely to ever be available in mobile forms.

Regarding unblinding, it may be better to use several different types of dependent variables, such as heart rate, plasma levels, and neuroimaging data, together with subjective responses to questionnaires. This would allow a better understanding of the phenomena under study on many different levels.

Epistemically fair approaches to indigenous knowledge have already resulted in important concepts such as plant teachers and a parallel between cellular biology and shamanic visions.

Biomedicine and psychiatry can learn from medical anthropology, and can also identify transcultural continuities and ontological equivocations. The initiative to bring biomedical science to the forest can be criticized as an attempt to medicalize shamanism, but can also constitute a possibility of intercultural dialogue centered on innovation and solving “problem nets”.

Conclusion: Towards ethical and sustainable regulation

The Brazilian National Heritage Institute has started a procedure to register the culture of ayahuasca, which should be conceived as a collective right of each community. This culture should be protected from patents by third parties or other kinds of cultural expropriation.

Indigenous people made a commitment to use their traditional medicine in a wise and responsible way, and to look after the knowledge and aspects of the original practices and knowledge transmission for the new generations. They also recommended the creation of an Indigenous Ethical Council on Traditional Medicine.

There are several ways to respect traditional indigenous medicine, including creating health services for indigenous people, taking into account their prevention methods, healing practices, and traditional medicines, and creating ethnobotany research centers to juxtapose Western botanical taxonomy with the indigenous taxonomy.

Indigenous peoples have the right to maintain, control, protect, and develop their cultural heritage, traditional knowledge, and traditional cultural expressions.

In Brazil, traditional knowledge is the information or practice by indigenous peoples, traditional communities, and traditional farmers concerning the direct or indirect properties and their use associated with a genetic heritage. A communal protocol is required to establish the procedures to access traditional knowledge and then celebrate a benefit-sharing agreement. In Brazil, indigenous peoples have the right to maintain their health practices, including the use of their traditional medicines. States and companies must observe the established structures of authority and representation within and outside the communities.

Similar norms can be applied in Colombia and Peru. Financial compensation cannot address the harm caused by epistemic injustices and unfair regulatory models.

Psilocybin, the active ingredient in ayahuasca, has entered biomedicine through interactions with Mazateca indigenous people in Mexico. However, there is still largely neglected discussion regarding indigenous rights and proper traditional medicine regulatory approaches.

The Amazon forest is rapidly approaching the dieback tipping point in its ecological equilibrium capacities. Regulation of ayahuasca use as a therapeutic tool in psychiatry in a fair manner with indigenous peoples is essential for the preservation of the Amazon forest and ayahuasca per se.

Study details

Compounds studied

Topics studied
Equity and Ethics

Study characteristics

0 Humans


Authors associated with this publication with profiles on Blossom

Eduardo Schenberg
Eduardo Ekman Schenberg is an entrepreneur and a neuroscientist who works to bring radical and disruptive innovations in psychiatry, developing safer and better treatments than currently available, focusing on severe cases of drug addiction, depression, and trauma, among others. After more than ten years treading a solid academic trajectory in the interface between psychology, neuroscience, and psychiatry, Eduardo is now developing initiatives to provide new psychiatric treatments. He also studies the many facets of the amazonian medicine ayahuasca, bridging science and traditional knowledge and practices.