Dreaming Arts winged sun Dreaming Arts
← Back to Blog

Ceremonial Ayahuasca - The Scientific and Legal picture

Lore Solaris
Ceremonial Ayahuasca and global resaerch
What does science and research tell us about ceremonial Ayahuasca? Digitial illustration by Lore Solaris - Ai assisted
Ceremonial Ayahuasca - The Scientific and the Legal picture

A reference guide to the research, the legal decisions, and the growing global evidence base — including Australian research you may not know exists


By the Grace of Great Spirit,

If you have found this page, you are probably looking for something specific — evidence, not opinion. You may be a researcher, a journalist, a legal professional, a policy maker, or someone who has encountered ayahuasca in your own life and wants to understand what the science actually shows. You may have read headlines that told one story and wondered whether there was more to it. There is.

This post exists to share that record directly and without embellishment. What follows is a curated collection of peer-reviewed scientific research, legal decisions from the highest courts, and government regulatory frameworks from around the world — all bearing on the safety, the therapeutic potential, and the legal standing of ayahuasca as a ceremonial sacrament and as a subject of serious scientific inquiry.

I have long been studying and researching this topic as a practitioner and for the protection and deeper understanding of our Holy sacrament. I have gathered them here because they are the best available evidence, produced by credible institutions, published in peer-reviewed journals, and decided by courts whose authority is beyond dispute. They speak for themselves.

What you will find in this post:

- The landmark 2006 United States Supreme Court decision upholding the right of a religious community to use ayahuasca as a sacrament — a unanimous ruling that set the global legal benchmark.

- The Brazilian government's formal regulatory framework, in place since 1987 and strengthened in 2010, protecting ayahuasca use in religious and ceremonial contexts as a matter of constitutional religious freedom.

- Canada's Health Canada exemption framework, under which religious organisations have been granted formal legal protection for ceremonial ayahuasca use since 2017.

- The Hoasca Project — the foundational biomedical study of long-term UDV church members conducted by an international team from UCLA and the University of Campinas in the Brazilian Amazon, which found no evidence of toxicity, cognitive impairment or adverse health effects in long-term ceremonial users. This is the study that informed the US Supreme Court.

- The Spanish Santo Daime studies led by Dr José Carlos Bouso and the ICEERS Foundation — longitudinal research on long-term religious ayahuasca users in Spain, finding no evidence of psychological maladjustment, mental health deterioration or cognitive impairment. Users outperformed matched non-using controls on cognitive tests.

- The Global Ayahuasca Project — the largest scientific study of ayahuasca drinking ever conducted, led by Dr Daniel Perkins at the University of Melbourne, with over 10,800 participants from more than 50 countries. An Australian-led research programme producing ongoing peer-reviewed findings on safety, wellbeing, and therapeutic outcomes in naturalistic and ceremonial settings.

- Systematic reviews published in peer-reviewed journals covering the safety profile, adverse effects, and therapeutic potential of ayahuasca across multiple clinical conditions — including treatment-resistant depression, anxiety, and substance use disorders.

- The 2023 ICEERS report on global ayahuasca consumption and media-attributed deaths — which estimated over four million lifetime users across the Americas, Europe, Australia and New Zealand, and found that no media-reported deaths had been corroborated by independent forensic analysis.

This is not a complete picture of a simple story. The science is evolving, the legal landscape differs by jurisdiction, and there are genuine questions about context, safety protocols, and appropriate frameworks that researchers and communities are actively working through. Any honest account of this subject acknowledges that.

But the idea that there is no credible science, no serious legal precedent, and no legitimate framework for understanding Ayahuasca as anything other than a dangerous illegal drug — that idea is not supported by the evidence. It has not been for some time.

What follows is the evidence.

Note: The research and legal references in this post are drawn from publicly available sources including PubMed, PLOS, the United States Supreme Court, Health Canada, and the publications of the University of Melbourne's Psychedelics Research and Therapeutics Unit. All links are current as of the date of publication. This post is not legal advice and does not constitute advocacy for any illegal activity in any jurisdiction.

PART ONE — THE LEGAL RECORD


United States Supreme Court

Gonzales v. O Centro Espírita Beneficente União do Vegetal 546 U.S. 418 (2006)

Decided February 21, 2006. Unanimous 8–0 ruling.

The United States Supreme Court upheld the right of a Brazilian-American religious community — the União do Vegetal — to use Hoasca (Ayahuasca) as a sacramental tea in their religious ceremonies, notwithstanding its classification as a controlled substance under the Controlled Substances Act. The Court held that the government had failed to demonstrate a compelling interest sufficient to override the protections of the Religious Freedom Restoration Act 1993. The ruling was unanimous. Chief Justice Roberts delivered the opinion of the Court.

This decision is the global legal benchmark for the religious use of ayahuasca. It was the outcome of a legal process initiated after federal agents seized the church's sacramental tea. The scientific evidence presented during that process — including the findings of the Hoasca Project — was examined by the Court.

• Full decision (Justia): Ful US Supreme Court decision re: Ayahuasca

• Full decision (Cornell Law): Full US Suprme Court Decision re: Ayahuasca

• Case summary (First Amendment Encyclopedia): Case Summary - First Ammendment Encyclopedia

• UDV official case page including oral argument transcript: UDV Official case page


Church of the Holy Light of the Queen v. Mukasey — Oregon Federal District Court (2009)

The case: Following a government seizure of ayahuasca sacrament from the home of a spiritual leader in Ashland, Oregon, two Santo Daime churches — the Church of the Holy Light of the Queen and the Céu da Divina Rosa (Church of the Divine Rose) in Portland — brought suit in federal court seeking an injunction protecting their religious use of ayahuasca.

The decision: On 18 March 2009, US District Court Judge Owen Panner ruled that the Religious Freedom Restoration Act protects the Santo Daime's use of Ayahuasca as part of their sincere religious practices. The court closely followed the Supreme Court's reasoning in the UDV case and found that the government had failed to establish either a compelling state interest in forbidding the church's use of ayahuasca, or that outright prohibition was the least restrictive means of furthering its interests. The ruling was confirmed and simplified in January 2012 — the federal government was enjoined from prohibiting the churches' importation, storage, distribution, and use of ayahuasca for religious ceremonies.

The judge concluded that the Religious Freedom Restoration Act requires that the plaintiffs be allowed to import and drink the sacramental tea for their religious ceremonies, subject to reasonable restrictions. The Oregon Board of Pharmacy had already separately exempted the church from state DMT restrictions.

This was the second major US legal victory for ayahuasca religious communities, building directly on the UDV Supreme Court precedent three years earlier.


Church of the Celestial Heart v. Garland - DEA Settlement (2025)

The case: The Church of the Celestial Heart is a Santo Daime-inspired Ayahuasca church based in Tulare, California, founded by Kai Karel. Following the arrest of a pastor, the church filed suit in April 2023 against the federal government under the Religious Freedom Restoration Act, seeking legal protection for their ceremonial use of Ayahuasca. Attorneys Sean McAllister and Jack Silver represented the church.

In January 2024, the court made an important procedural ruling — rejecting the federal government's argument that the Drug Enforcement Administration, rather than the courts, should perform the balancing-of-interests analysis under the Religious Freedom Restoration Act. This was a significant win for religious freedom advocates, affirming that it is the courts — not a law enforcement agency — that have the authority to weigh religious freedom claims against government interest.

The settlement: As of 5 May 2025, the Church of the Celestial Heart is officially protected by US law. Their sacramental use of Ayahuasca within sacred ceremony is authorised and acknowledged by both the Drug Enforcement Administration and the Department of Justice. Their sacred work and sacrament are now protected by the same constitutional and regulatory protections afforded to all recognised religious practices in the United States.

This settlement followed a similar settlement between the Church of the Eagle and the Condor and the DEA in 2024 — the first time religious rights to ayahuasca were won via settlement rather than court ruling. Together these cases represent a significant acceleration in the legal recognition of ayahuasca religious communities in the United States.

The Church of the Celestial Heart's statement on their legal victory reads: "May this moment of triumph and this celebration of freedom ripple far beyond our circle to all those who walk this path with sacredness and devotion. May our journey be an example and a guiding light to others who choose to serve Ayahuasca with integrity, sincerity, truth, and authentic service to humanity."

  
Brazil — Government Regulatory Framework

Brazil has formally authorised the religious and ceremonial use of Ayahuasca since 1987, when the National Council on Drug Policy (CONAD) first issued regulations protecting ritual use. This protection has been reinforced and expanded in the decades since.

In 2010, CONAD Resolution 01/10 established a detailed regulatory framework — a "deontology of use" — setting out the conditions and ethical principles governing religious and ceremonial ayahuasca practice. This regulation confirmed the legitimacy of Ayahuasca use within the context of religious practice under Brazil's Constitutional protections for freedom of belief and worship.

• ICEERS Brazil legal overview: https://www.iceers.org/en/legal-info/brazil/

• Academic analysis of Brazilian regulation (PubMed): https://pubmed.ncbi.nlm.nih.gov/21856141/

• Reassessment of Brazilian regulation (academic journal): https://www.tandfonline.com/doi/full/10.1080/09687637.2024.2415319


CONFEN — The Federal Council of Narcotics (1987 and 1992)

The Government Investigation That Started It All

In 1985, Brazil temporarily added Ayahuasca's plant ingredients to its prohibited substances list. Religious communities immediately petitioned for reversal on freedom of religion grounds. The Federal Council of Narcotics (CONFEN) responded by forming a dedicated multidisciplinary working group that spent two years investigating — visiting communities across the Amazon, observing ceremonies, and conducting comprehensive research.

In September 1987, the working group delivered its final report to CONFEN, led by counsellor Dr Domingos Bernardo Gialluisi da Silva Sá. The conclusion: the religious rituals conducted with Ayahuasca did not bring injuries to social life. On the contrary, they contributed to better social integration. CONFEN's plenary approved the report unanimously and the plant species were permanently removed from Brazil's prohibited substances list.

In 1992, following an anonymous complaint, the question was re-examined. The same counsellor conducted a fresh review. The conclusion was again approved unanimously: there were no reasons to modify the 1987 finding. The 1992 decision settled the matter definitively. CONFEN's successor body CONAD has maintained and expanded this protection ever since, culminating in the comprehensive regulatory framework of 2010.

The investigation was notable for its rigour — the working group's lead counsellor, Dr Domingos Bernardo Gialluisi da Silva Sá, personally participated in a ceremony as part of his research, a detail that speaks to the seriousness with which the Brazilian government approached the question.

The CONFEN process is significant not only for its conclusion but for its method — a government body that took the question seriously, went into the field, participated in the process it was investigating, and reached a conclusion grounded in evidence rather than assumption. That process and its outcome remain the foundation of Brazilian law on this subject to this day.

• Spirit Vine — Full English description of CONFEN proceedings and translated official text: https://spiritvineretreats.com/ayahuasca/brazilian-law-regarding-ayahuasca/

• Erowid — Notes on Brazilian Ayahuasca Law including 1987 CONFEN conclusion in direct quotation: https://www.erowid.org/chemicals/ayahuasca/ayahuasca_law6.shtml

• Chacruna — Controversies on Environmental Legislation on Ayahuasca in Brazil: https://chacruna.net/ayahuasca_conservation_laws_brazil/

• MAPS — Contemporary account of the 1992 CONFEN definitive decision: https://maps.org/news-letters/v03n4/03429aya.html

• ICEERS — Brazil legal overview: https://www.iceers.org/en/legal-info/brazil/

• Taylor and Francis — Peer-reviewed analysis of the full CONFEN to CONAD regulatory history (2024): https://www.tandfonline.com/doi/full/10.1080/09687637.2024.2415319


Canada — Health Canada Religious Exemptions

On 5 June 2017, Health Canada granted Section 56 exemptions to the Controlled Drugs and Substances Act to the Santo Daime Church Céu do Montréal and the União do Vegetal, formally protecting their ceremonial use of ayahuasca as a religious sacrament. Three additional churches received exemptions in May 2019. As of 2020, six religious organisations held formal legal exemptions.

Health Canada's basis for granting the exemptions included balancing the health and safety of Canadians with respect for the religious freedoms of these communities protected under the Canadian Charter of Rights and Freedoms.

• ICEERS Canada legal overview: https://www.iceers.org/en/legal-info/canada/

• Céu do Montréal official legal process account: https://santodaime.ca/legal-process/

• Canadian Public Health Association discussion document: https://www.cpha.ca/discussion-document-public-health-perspectives-future-psychedelics


Global Legal Status Overview

• Wikipedia — Legal status of ayahuasca by country: https://en.wikipedia.org/wiki/Legal_status_of_ayahuasca_by_country

• ICEERS international legal map: [https://www.iceers.org/ayahuasca/](https://www.iceers.org/ayahuasca/)

AUSTRALIA — HOW DMT BECAME ILLEGAL AND WHAT THE LAW CURRENTLY SAYS

The story of how Ayahuasca became illegal in Australia is one of the least examined aspects of this entire public conversation. It was never specifically criminalised through a deliberate, evidence-based legislative process. It became illegal as a downstream consequence of a United Nations treaty adopted in 1971 — a treaty that was itself primarily a political response to the counterculture of the 1960s, driven by the United States' domestic panic about LSD, rather than a product of considered research into specific substances.

On 21 February 1971, a conference in Vienna produced the Convention on Psychotropic Substances — a treaty designed to bring psychoactive substances under international control. DMT was included in Schedule I of this Convention, alongside LSD and other psychedelics. Australia, like most UN member states, ratified the Convention and implemented it through domestic scheduling law.

There is a critical detail about this Convention that is almost never discussed. The official Commentary on the Convention on Psychotropic Substances makes clear that psychedelic plants — and any plants — were not included in the Schedules and are not covered by the Convention at all. No plants or plant products are internationally scheduled under the 1971 Convention. The ayahuasca vine and the chacruna leaf — the two plants from which Ayahuasca is brewed — have never been internationally controlled. What is controlled is the isolated synthetic compound DMT. Australia applied that scheduling to the naturally occurring compound as it exists in plants and in the Ayahuasca brew — a choice that goes beyond what the Convention technically required.

In Australian law, DMT is a Schedule 9 prohibited substance under the Standard for the Uniform Scheduling of Medicines and Poisons — the highest level of restriction — making the possession, use, manufacture, supply, importation, or exportation of Ayahuasca illegal in every state and territory. Unlike the United States, Canada, and Brazil, Australia has never created a religious freedom exemption mechanism through which ceremonial communities can seek formal legal protection for their practice.

When the União do Vegetal church in Australia invested significant resources in a formal submission to the TGA seeking a religious exemption, there was no meaningful investigation in response — no expert consultations, no visits to communities, no examination of the international evidence. The contrast with Brazil's CONFEN process — where the government's lead investigator spent two years visiting communities, reviewing evidence, and personally participating in ceremony before reaching a decision — is a stark illustration of the difference between a process grounded in genuine inquiry and one that treats the question as already settled.

In 2023, the TGA reclassified psilocybin and MDMA from Schedule 9 to Schedule 8 for specific therapeutic indications, making Australia the first country in the world to nationally reschedule psychedelic substances for medical access. DMT and Ayahuasca were not included in this reform. DMT remains Schedule 9. That choice — to act on evidence for some substances while leaving others unchanged — is itself a decision that deserves scrutiny, particularly in light of the volume of international research, legal precedent, and community evidence that now exists on ayahuasca specifically.

The framework for change exists. The question is whether there is the political will to use it.

References:

PART TWO — THE FOUNDATIONAL SCIENCE


The Hoasca Project (1993–1996)
The Study That Informed the US Supreme Court

Grob CS, McKenna DJ, Callaway JC, Brito GS, Neves ES, Oberlaender G, Saide OL, Labigalini E, Tacla C, Miranda CT, Strassman RJ, Boone KB.
Human Psychopharmacology of Hoasca, A Plant Hallucinogen Used in Ritual Context in Brazil. - Journal of Nervous and Mental Disease, 1996; 184(2): 86–94.

The Hoasca Project was the first comprehensive biomedical investigation of the long-term effects of Hoasca (Ayahuasca) in human users. It was conducted in 1993 by invitation of the Medical Studies section of the União do Vegetal, by an international consortium from nine universities and research institutions across Brazil, the United States, and Finland. Led by Dr Charles Grob MD of the Division of Psychiatry at UCLA, and Dr Dennis McKenna PhD.

The study assessed 15 male long-term UDV members — minimum ten years of ceremonial use — against 15 matched controls who had never consumed Ayahuasca. Complete physical examinations, blood samples, neurological and cardiac monitoring, pharmacokinetic analysis, psychiatric diagnostic interviews, personality testing, and neuropsychological assessments were conducted.
  
Findings: No evidence of acute toxicity during sessions. No evidence of long-term toxicity or adverse health effects. Long-term users scored higher on cognitive tests than matched non-using controls. Many users reported that Hoasca and UDV membership had enabled them to address previous patterns of alcoholism and substance dependence. In the words of general coordinator Dr Dennis McKenna: "Hoasca is in no contexts toxic or harmful to the human body, does not cause any neurological, cognitive or personality dysfunctions."

This body of work directly informed the evidence considered by the United States Supreme Court in the UDV case.

• PubMed: https://pubmed.ncbi.nlm.nih.gov/8596116/

• ResearchGate full PDF: https://www.researchgate.net/publication/14604667_Human_Psychopharmacology_of_Hoasca_A_Plant_Hallucinogen_Used_in_Ritual_Context_in_Brazil

• UDV official Hoasca Project page: https://udv.org.br/en/scientific-research/hoasca-project/

• Botanical Dimensions project overview: https://botanicaldimensions.org/the-hoasca-project/

• MAPS original project proposal (1992): https://maps.org/news-letters/v03n3/03317aya.html
  

UDV Members — Substance Use Disorders Study (2018)

Largest UDV Study Ever Conducted

Fábregas JM, González D, Fondevila S, Cutchet M, Fernández X, Barbosa PCR, Alcázar MA, Bouso JC, Hallak JEC, Crippa JAS, Riba J. Assessment of Alcohol and Tobacco Use Disorders Among Religious Users of Ayahuasca. - Frontiers in Psychiatry, 2018.

This study assessed 1,947 UDV members aged 18 and over, recruited from 10 states across all major regions of Brazil — the largest study of UDV members ever conducted. Participants were compared against a national normative sample of 7,939 people using questionnaires developed by the World Health Organisation.

Findings: Members who had previously met diagnostic criteria for alcohol use disorder no longer did so after joining the UDV. Lower rates of current alcohol and tobacco use disorders compared to the national population. The study confirmed and significantly expanded the findings of the original Hoasca Project on the relationship between ceremonial ayahuasca use and substance use outcomes.

• PMC full text (open access): https://pmc.ncbi.nlm.nih.gov/articles/PMC5928846/

• PubMed: https://pubmed.ncbi.nlm.nih.gov/29740355/

• Frontiers in Psychiatry: https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2018.00136/full

PART THREE — THE SPANISH SANTO DAIME STUDIES


Bouso et al. — Longitudinal Study of Ritual Users (2012)
Most Cited Long-Term Safety Study in the Field

Bouso JC, González D, Fondevila S, Cutchet M, Fernández X, Ribeiro Barbosa PC, et al. Personality, Psychopathology, Life Attitudes and Neuropsychological Performance among Ritual Users of Ayahuasca: A Longitudinal Study. - PLOS ONE 7(8): e42421, 2012.

Conducted with members of the Santo Daime religious community in Barcelona, Spain. Assessed 127 regular ayahuasca users and 115 controls actively participating in non-ayahuasca religions, at baseline and one year later. This is the largest longitudinal study of long-term religious ayahuasca users ever conducted.

Findings: Users scored significantly lower on all psychopathology measures. Users showed better performance than controls on the Stroop test, the Wisconsin Card Sorting Test, and the Letter-Number Sequencing task. Better scores on the Frontal Systems Behavior Scale. The study concluded there was "no evidence of psychological maladjustment, mental health deterioration or cognitive impairment in the ayahuasca-using group." These results were consistent with earlier findings from smaller samples and constituted the first replication of those findings at this scale.

• PLOS ONE full text (open access): https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0042421

• ResearchGate PDF: https://www.researchgate.net/publication/283070607

• MAPS summary: https://maps.org/news/media/ritual-users-of-ayahuasca-a-longitudinal-study/


Bouso et al. — Santo Daime Spain Personality and Cognition Study (2026)

Most Recent Spanish Research

Bouso JC, Andión O, Fondevila Estévez S, González D, Alcázar-Córcoles MA, Kohek M, Guimarães dos Santos R, Hallak J, Riba J. Personality, Not Cognition, Distinguishes Chronic Ayahuasca and Cannabis Users from Non-Users. - Published 2026. ICEERS / Universitat Rovira i Virgili, Barcelona.

A cross-sectional study conducted with members of the Spanish Santo Daime Church comparing 69 regular ayahuasca users, 56 regular cannabis users, and 94 matched non-users on cognition, mental health, and personality. Participants were verified abstinent before testing.
  
Findings: No significant differences between groups on any neuropsychological measure. Chronic use of ayahuasca was not associated with detectable impairments in executive functioning, working memory, attention, or decision-making. Ayahuasca users showed no current psychopathological symptoms despite a higher lifetime prevalence of mood and anxiety disorders. Personality characteristics — not cognitive impairment — distinguished users from non-users.

• ICEERS summary: https://www.iceers.org/en/studies/personality-ayahuasca-cannabis-users/

• PubMed: https://pubmed.ncbi.nlm.nih.gov/41687467/

• National Elf Service review: https://www.nationalelfservice.net/mental-health/addiction/personality-not-cognition-sets-long-term-drug-users-apart/
  

Bouso et al. — Santo Daime Anxiety and Emotional States Study (2007)

Bouso JC et al. Effects of Ayahuasca on Psychometric Measures of Anxiety, Panic-Like and Hopelessness in Santo Daime Members. - Journal of Ethnopharmacology, 2007.

Conducted at the Santo Daime church with members who had used Ayahuasca ceremonially for a minimum of ten consecutive years. Double-blind, placebo-controlled procedure administered within the church ceremony itself.

Findings: Participants scored lower on scales for panic and hopelessness-related states while under the acute effects of Ayahuasca. The results were discussed in terms of the possible use of Ayahuasca in alleviating signs of hopelessness and panic-like symptoms.

• PubMed: https://pubmed.ncbi.nlm.nih.gov/17532158/

• ScienceDirect: https://www.sciencedirect.com/science/article/abs/pii/S0378874107002139
  

American Santo Daime Members Health Study (2008)

Halpern JH, Sherwood AR, Passie T, Blackwell KC, Ruttenber AJ. Evidence of Health and Safety in American Members of a Religion Who Use a Hallucinogenic Sacrament. - Medical Science Monitor, 2008.

Assessed 32 American members of the Santo Daime Church — the precise community whose case went to the US Supreme Court — via physical examination, drug use timelines, and comprehensive psychological measures. Members attended services weekly with a lifetime range of 20 to 1,300 ceremonies.

Findings: Physical examination and test scores revealed healthy participants who attributed significant health benefits to their ceremonial ayahuasca use.

• PubMed: https://pubmed.ncbi.nlm.nih.gov/18668010

PART FOUR — THE GLOBAL AYAHUASCA PROJECT


University of Melbourne — The World's Largest Ayahuasca Study

Led by Dr Daniel Perkins, Senior Research Fellow and Head of the Psychedelics Research and Therapeutics Unit at the University of Melbourne, the Global Ayahuasca Project is the largest scientific study of Ayahuasca drinking ever conducted. Over 10,800 participants from more than 50 countries participated in an online survey between 2017 and 2019, released in six languages. The project is a collaboration between the University of Melbourne, the University of Campinas in Brazil, ICEERS in Spain, the University of Zurich, and Mendel University in the Czech Republic.

The project has produced multiple peer-reviewed publications examining safety, mental health outcomes, wellbeing, adverse effects, and the influence of context and setting on outcomes.

Project website: https://www.globalayahuascaproject.org

University of Melbourne research group: https://mspgh.unimelb.edu.au/research-groups/centre-for-health-equity/psychedelics-research-and-therapeutics


Publication 1 — Largest Mental Health Analysis (2024)

Perkins D, Sarris J, Cowley-Court T, Aicher H, Tófoli LF, Bouso JC, Opaleye E, Halman A, Galvão-Coelho N, Schubert V. Associations Between Ayahuasca Use in Naturalistic Settings and Mental Health and Wellbeing Outcomes: Analysis of a Large Global Dataset. - Journal of Psychoactive Drugs, November 2024.

The largest analysis ever conducted of associations between naturalistic Ayahuasca use and mental health. Final analysis included 7,576 participants, average age 41, 47% female, drawn from more than 50 countries.

Findings: Greater frequency of ceremonial ayahuasca use was associated with higher scores on psychological wellbeing measures. Mystical experiences and personal insights during ceremonies were significant contributors to positive outcomes. Effects were particularly pronounced for participants with prior mental health challenges. The study authors noted that Ayahuasca has been used for centuries by Indigenous communities for healing and spiritual purposes and that its effects on mental health in contemporary settings are an area of growing scientific interest.

• PubMed: https://pubmed.ncbi.nlm.nih.gov/39579192/

• Journal of Psychoactive Drugs: https://www.tandfonline.com/doi/full/10.1080/02791072.2024.2424288

• PsyPost plain language summary: https://www.psypost.org/largest-ever-survey-on-ayahuasca-highlights-links-to-better-mental-health-and-wellbeing/


Publication 2 — Context and Setting Study (2021)

Perkins D, Schubert V, Simonová H, Tófoli LF, Bouso JC, Horák M, Galvão-Coelho NL, Sarris J. Influence of Context and Setting on the Mental Health and Wellbeing Outcomes of Ayahuasca Drinkers: Results of a Large International Survey. - Frontiers in Pharmacology, 2021.

Findings: Ceremonial and religious contexts with experienced facilitation produced better mental health and wellbeing outcomes than unstructured or recreational use. Context, setting, and the presence of an experienced facilitator are significant variables in outcomes.

• Frontiers in Pharmacology: https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2021.623979/full


Publication 3 — Adverse Effects Study (2022)

Bouso JC et al., Perkins D. Adverse Effects of Ayahuasca: Results from the Global Ayahuasca Survey. - PLOS Global Public Health 2(11): e0000438, 2022.

Analysed adverse effects across the full 10,836-participant dataset. Found that while adverse effects including nausea, vomiting, and psychological difficulty during sessions occur and should be taken seriously, serious lasting adverse effects were rare. Adverse effects were contextualised against the broader wellbeing and mental health data from the same survey.

• PLOS Global Public Health (open access): https://journals.plos.org/globalpublichealth/article?id=10.1371/journal.pgph.0000438
  

Publication 4 — Longitudinal Wellbeing Study (2022)

Perkins D, Pagni BA, Sarris J, Barbosa PCR, Chenhall R. Changes in Mental Health, Wellbeing and Personality Following Ayahuasca Consumption: Results of a Naturalistic Longitudinal Study. - Frontiers in Pharmacology, 2022.

Followed participants over 12 months — baseline, 7 days, 1 month, 6 months, and 12 months. Found rapid, robust, and sustained improvements in depression and anxiety symptoms.

• Frontiers in Pharmacology: https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2022.884703/full


Publication 5 — Long-Term Mental Health Outcomes (2025)

Perkins D et al. Long-Term Mental Health and Wellbeing Outcomes Associated with Naturalistic Ayahuasca Consumption. - Journal of Psychoactive Drugs, 2025. University of Melbourne Human Research Ethics Committee approved.

66 ayahuasca-naïve participants recruited from two independent ayahuasca churches in North America, followed for 12 months. Found rapid, robust, and enduring improvements in symptoms of depression and anxiety sustained at the 12-month mark.
  
• PMC full text: https://pmc.ncbi.nlm.nih.gov/articles/PMC12353293/

PART FIVE — SYSTEMATIC REVIEWS AND CLINICAL RESEARCH


Systematic Review — Safety and Adverse Events (2024)

White E, Kennedy T, Ruffell S, Perkins D, Sarris J. Ayahuasca and Dimethyltryptamine Adverse Events and Toxicity Analysis: A Systematic Thematic Review. - Journal of Psychoactive Drugs, 2024.
  
Reviewed 78 relevant articles from PubMed, Web of Science, PsycINFO, ClinicalTrials.gov, and Embase. Conclusion: ayahuasca or DMT is generally safe at ceremonial doses, though some adverse events have been reported. Animal models using higher doses showed toxicity, confirming the dose-dependence of risk.

• Sage Journals: https://journals.sagepub.com/doi/10.1177/10895818241230916
  

Systematic Review — Therapeutic Effects Across Conditions (2023)

A Systematic Review on the Therapeutic Effects of Ayahuasca.

Published in peer-reviewed journal, covering 66 studies published up to December 2022 from the PubMed database.

Findings: Ayahuasca may have beneficial effects on depression, anxiety, neurobiological conditions, and has demonstrated anti-inflammatory and antimicrobial properties. The number of studies addressing therapeutic potential has been growing consistently.

• PubMed full text (open access): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10346174/


Randomised Placebo-Controlled Trial — Antidepressant Effects

Palhano-Fontes F et al. Rapid Antidepressant Effects of the Psychedelic Ayahuasca in Treatment-Resistant Depression: A Randomized Placebo-Controlled Trial. - Psychological Medicine, 2019.

The first randomised, double-blind, placebo-controlled trial to test a psychedelic substance in treatment-resistant depression. 29 patients. Significant antidepressant effects of Ayahuasca observed at all time points compared to placebo. Conclusion: the study brings new evidence supporting the safety and therapeutic value of Ayahuasca, dosed within an appropriate setting, to help treat depression.

• PubMed: https://pubmed.ncbi.nlm.nih.gov/29903051/


DMT Clinical Trial — Nature Medicine (2026)

Erritzoe D, Barba T, James E et al. A Short-Acting Psychedelic Intervention for Major Depressive Disorder: Randomized Placebo-Controlled IIa Trial of Intravenous Dimethyltryptamine (DMT) with Therapeutic Support. - Nature Medicine, 2026. Imperial College London.

A Phase IIa randomised clinical trial finding that participants with depression treated with DMT had greater reductions in depression severity compared to placebo, with effects lasting up to six months in some participants.

• Imperial College London: https://www.imperial.ac.uk/news/articles/2026/ayahuasca-compound-has-significant-and-lasting-effect-on-depression-/


Animal Model Systematic Review — Safety at Ceremonial Doses (2023)
  
Daldegan-Bueno D et al. The Current State of Ayahuasca Research in Animal Models: A Systematic Review. - Progress in Neuro-Psychopharmacology and Biological Psychiatry, 2023.

32 studies reviewed across rodents, primates, and zebrafish. Conclusion: Ayahuasca is safe at ceremonial-based doses - confirming the dose-dependence of risk and the safety of the ceremonial dosing context.

• PubMed: https://pubmed.ncbi.nlm.nih.gov/36863501/


CNS Spectrums — Pharmacology, Safety and Therapeutic Effects (2024)
  
Dos Santos RG, Hallak JEC. Ayahuasca: Pharmacology, Safety and Therapeutic Effects. - CNS Spectrums, 2024. Cambridge University Press.

A comprehensive review of the pharmacology, safety profile, and emerging therapeutic evidence base for Ayahuasca, published in a leading neuropsychiatric journal.

• Cambridge Core: https://www.cambridge.org/core/journals/cns-spectrums/article/ayahuasca-pharmacology-safety-and-therapeutic-effects/547D19C644BE45A39257C1FCD3E3A5F5


Wellbeing Study — Better Than Average Health in Ayahuasca Users
  
The ICEERS Netherlands study demonstrated that Ayahuasca ceremony participants have better than average wellbeing and fewer chronic and lifestyle-related diseases compared to the general population. They are more physically active and have a better overall diet. Almost all participants answered positively or very positively when asked how ayahuasca had influenced their lives. Two out of three reported a general improvement in health and wellbeing.

• ICEERS summary with statistics: https://www.iceers.org/en/articles/reports/four-million-people-have-taken-ayahuasca-worldwide/

PART SIX — THE ICEERS GLOBAL RESEARCH FOUNDATION


The International Center for Ethnobotanical Education, Research and Service (ICEERS) is a philanthropic organisation headquartered in Barcelona and the Netherlands, dedicated to integrating the traditional use of plant medicines as therapeutic tools in society and defending the human rights of people using plants for ancestral cultural reasons. ICEERS has produced the most comprehensive collection of peer-reviewed ayahuasca research in the world, including the ICEERS Technical Report on Ayahuasca — signed by ten of the world's leading ayahuasca researchers and specifically designed to provide information to policy makers, judges, lawyers, and officials involved in legal cases relating to ayahuasca.

  
2023 Global Consumption and Deaths Report:

ICEERS estimates global lifetime Ayahuasca use at over four million people across the Americas, Europe, Australia, and New Zealand. The report found that no media-reported deaths attributed to ayahuasca have been corroborated by independent forensic analysis.

• Full report PDF: https://www.iceers.org/wp-content/uploads/ICEERS_Ayahuasca_deaths_en.pdf

• ICEERS summary: https://www.iceers.org/en/articles/reports/ayahuasca-global-consumption-deaths/

• IDPC hosted version: [https://idpc.net/publications/2023/07/ayahuasca-global-consumption-and-reported-deaths-in-the-media](https://idpc.net/publications/2023/07/ayahuasca-global-consumption-and-reported-deaths-in-the-media)


ICEERS Technical Report on Ayahuasca:

• https://www.iceers.org/ayahuasca-technical-report/


ICEERS Full Scientific Studies Library:

• https://www.iceers.org/en/category/studies/
  

ICEERS Main Website:

• https://www.iceers.org/en/](https://www.iceers.org/en


This reference list will be updated as new research is published. It is provided for educational and informational purposes only. Nothing in this post constitutes legal advice or advocacy for any illegal activity in any jurisdiction. Readers are responsible for understanding and complying with the laws of their own region.

Last updated: September 2026.


Legal Notice:

This blog and book contains cultural, historical, and autobiographical descriptions of traditional plant-sacrament ceremonies, including references to Ayahuasca and other restricted substances under Australian law. These descriptions are provided for educational and documentary purposes only. Nothing in this book or this blog is intended to encourage, promote, or facilitate the use, preparation, distribution, or procurement of any illegal substance or activity in any jurisdiction.  
  
Readers are responsible for understanding and complying with the laws in their own region. The author and publisher disclaim all liability arising from the misuse or misinterpretation of the material contained herein.  
  
  
Cultural Respect Statement

The ceremonial traditions, songs, teachings, and healing practices referenced in this work belong to specific Indigenous cultures, spiritual lineages, and ancestral guardians. They are shared here with deep respect and gratitude. These traditions should be approached with humility,