The Shipibo Ceremonial Use of Ayahuasca to Promote Well-Being: An Observational Study

This observational study (n=200) investigated the well-being of individuals staying in a center completing an indigenous Shipibo healing program (which consists of a series of ayahuasca sessions) over the course of one year. The authors found that the healing program significantly improved the psychological well-being of individuals, and that decentering may have been a mediating factor in this effect.


“Promoting well-being is one of the main goals to improve health in the world. We examined the well-being and quality of life over the course of one year in a sample that participated in an Indigenous Shipibo healing program where traditional healers work in a series of ayahuasca ceremonies. We also explored the role of decentering as a mediator of psychological well-being. Participants who attended the program responded to an online survey that included a Psychological Well-Being Scale; Oxford Happiness Questionnaire; The World Health Organization Quality of Life Spirituality, Religiousness, and Personal Beliefs scale; the WHO Quality of Life-BREF scale; and Decentering scale. Baseline (T0) and postassessment (T1) were completed by 200 individuals. Of these, 101 completed the follow-up assessment at three months (T2), 91 at 6 months (T3), and 94 at 12 months follow-up (T4) after leaving the center. ANOVA test was performed in a representative subsample to control the passing of time two months before attending the program (T-1). Pearson’s test was performed to examine the relationship between psychological well-being and decentering during the period of T0 and T1. A significant increase was observed in all the scales at all time points (p ≤ 0.01). The subgroup analysis performed in a representative subsample allowed us to infer that the significant differences in outcomes are due to the effect of their stay at the center and not the passing of time. We found a relationship between decentering and the improvement of psychological well-being (r = 0.57; p < 0.01). Our results suggest that the Indigenous Shipibo healing work with ayahuasca has value to improve long-term well-being and quality of life for Westerners.

Authors: Debora Gonzalez, Jordi Cantillo, Irene Perez, Maria Carvalho, Adam Aronovich, Magi Farre, Amanda Feilding, Jordi E. Obiols & José Carlos Bouso



In recent years, a growing interest in well-being has developed, with the World Health Organization (WHO) defining mental health as “a state of complete physical, mental and social well-being”. However, there is no consensus on the definition of well-being, and clinical research is rooted in two complementary schools of thought.

Traditional medicine is the sum total of the knowledge, skill, and practices based on theories, beliefs, and experiences indigenous to different cultures, and includes herbal medicines. Governments and consumers are now beginning to consider integrating traditional medicine practices into health service delivery.

Ayahuasca is an herbal concoction made from the stalks of the vine Banisteriopsis caapi and the leaves of the bush Psychotria viridis. It has been used for ritual and healing purposes since pre-Columbian times and has shown efficacy as a rapid antidepressant.

Ayahuasca has become popular outside of its native Amazonian habitat through three ways: religions that use ayahuasca as a sacrament, psychonautic use of ayahuasca by Western people, and cross-cultural vegetalismo or Indigenous-style ayahuasca healing ceremonies.

The absence of international regulation of ayahuasca use poses a number of serious risks, including desecration of Indigenous knowledge, unwanted pharmacological interactions, and exposure to unreliable information and unqualified and unethical practitioners.

The World Health Organization has promoted international recognition of traditional medicine by regulating the products, practices, and practitioners. This has a reciprocal impact on the safety of doctors and patients, both in the countries of origin and in the countries that import medicinal practices and products.

Traditional Context

This article presents the results of a longitudinal observational study of Western people attending retreats at the Temple of the Way of Light in Iquitos, Peru. The ceremonies are run by five male and female Shipibo onanyabo, supported by two Western facilitators.

According to the onanyabo, the following ceremonies aim to cleanse and clear “dense energies” that participants may carry. These energies are often rooted in past difficult life episodes, particularly childhood experiences.

The Shipibo use icaros, as well as Nicotiana rustica, Mapacho, Aztec, Brazilian, or strong tobacco, and several perfumes to help the person “blossom” and attract positivity into their lives.

The present study investigated the long-term effects of ayahuasca on psychological well-being, subjective well-being, spiritual well-being, quality of life, and decentering. The results showed that psychological well-being was improved after drinking ayahuasca, and this effect was still maintained after a year.


This study was part of a broader research project that aims to prospectively assess the long-term effects of ayahuasca on psychopathological symptoms in different subsamples with depression, anxiety, posttraumatic stress disorder, and grief.

Participants and Procedure

Participants were enrolled between 2015 and 2017 and the follow-up period of one year was concluded in 2018. They drank ayahuasca between 1 and 12 times in a ceremonial context.

A total of 200 participants were eligible for the analysis. They had to be 18 years or older and not have a mental disorder, be taking medication, have a heart condition, have chronic high blood pressure, or be pregnant.

Participants were assessed 15 days before attending the retreat, and 3 months, 6 months, and 12 months after leaving the retreat. Only those who responded baseline and postassessment were finally included in the analysis.

Quality of Life

The WHO Quality of Life-BREF is a shorter version of the original WHOQOL-100, and comprises 24 items, scored on a 4 – 20 scale.

Ayahuasca Samples Analyses

Two ayahuasca samples were collected during the participants’ enrollment and analyzed. The samples contained 2 mg/ml DMT, 2 mg/ml harmine, 0.37 mg/ml harmaline, and 1 mg/ml tetrahydroharmine.

Statistical Analyses

Baseline characteristics, setting variables, persistent adverse effects, benefits of ayahuasca over time, and risk’s perception of the ayahuasca use in the participants’ original countries were analyzed descriptively. Effect sizes were calculated using Cohen’s d.

In order to evaluate homogeneity between the group that completed the follow-up at T1 and a subgroup that completed an additional assessment at T-1, we performed repeated measures analysis of variance with post hoc Bonferroni correction.


Out of 437 participants, 90.8% signed the informed consent form, but 18.4% were excluded because baseline assessment was not available. Finally, 200 participants were eligible for the analysis.

Risk’s Perception of the Ayahuasca Use in the Participants’ Original Countries

92.5% of the sample wished to continue taking ayahuasca, but only 14.9% drank ayahuasca in the 12 months after leaving the center.

92% of the sample affirmed being exposed to risks when taking ayahuasca in their country of origin, such as legal charges and the lack of guarantees regarding the composition of ayahuasca.


In this prospective, observational non-controlled study, participants who used ayahuasca in a ceremonial Shipibo context reported increased psychological well-being, subjective well-being, spiritual well-being, and quality of life over one year.

Well-being is a complex construct that includes physical, mental, and social well-being. Ayahuasca users show higher well-being than those who had taken classic psychedelics such as LSD or Psilocybe mushrooms, especially in life satisfaction, social relationships, spiritual awareness, and attitudes about self and life. The alternative medicine used in ritual settings may administer an especially large dose of “performative efficacy”, which relies on the power of belief, imagination, symbols, meaning, expectation, persuasion, and self-relationship.

Medical intervention by indigenous healers is not explicable by our Western, materialist worldview. Expanded science is necessary to establish the validity of this medical intervention.

The effect size is high in all PWBS total assessments, with self-acceptance being the subscale that presents a higher improvement after the retreat and follow-up assessments. The reflection process of the experience during the integration sessions may allow for the organic emergence of new meanings about the self.

Decentering is an important mechanism of change that enables the person to disidentify from internal experiences and reduce reactivity to thought content. This ability is enhanced after taking ayahuasca, and is maintained over one-year follow-up. Given that the development of this skill has not been formally taught in the ayahuasca ceremonies of those previous studies, we hypothesize that it could be acquired and sustained long-term through an experiential learning process with “master plants”.

The naturalistic design of this study does not allow us to isolate the effects of ayahuasca from the other diverse variables in the setting, and a placebo control group is not possible. Moreover, the sample selected is not representative of the general population.

Vegetalismo, which includes the use of ayahuasca and many other plant medicines, is the primary operational health-care system in the Peruvian jungle, but there is no international regulation of this medical system. This study hopes to contribute to the further recognition of ayahuasca as a herbal medicine.


Authors associated with this publication with profiles on Blossom

José Carlos Bouso
José Carlos Bouso is a Clinical Psychologist with a PhD in Pharmacology and is the current Scientific Director at ICEERS.

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