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Ayahuasca Safety Profile

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Studies in both animals and healthy humans have shown that ayahuasca is a physically and psychologically safe substance1,2 when its composition is known and when it is administered in controlled doses in appropriate environments with the necessary support.

About

What is ayahuasca?

Ayahuasca is a decoction of the Amazonian vine Banisteriopsis caapi. The word “ayahuasca” is a Quechua term commonly translated as “the vine of the dead” or “the rope of the dead.” Different Amazonian peoples have dozens of names for the brew and its variations, embedded in complex lineages of traditional practices and knowledge.

The brew is made by combining the vine with other Amazonian medicinal plants, most commonly Psychotria viridis (chacruna) or Diplopterys cabrerana (chaliponga or chagropanga). These admixture plants contain dimethyltryptamine (DMT), which becomes orally active through the monoamine oxidase inhibiting (MAOI) action of the beta-carboline alkaloids present in Banisteriopsis caapi.

Amazonian peoples use ayahuasca as:

  • a medicine
  • a channel of communication with the natural world
  • a tool for divination
  • a means of strengthening social relations

Ayahuasca is inseparable from many Indigenous and traditional cosmologies and is central to cultural identity and political self-determination. In recent decades, it has spread beyond its historical territories as people worldwide have become interested in its therapeutic and psychospiritual dimensions.

Risks to Consider

Physical risks related to ayahuasca pharmacology

  • Ayahuasca does not produce toxicity in the body or brain under controlled conditions.
  • Risks may arise when the source or composition of the brew is unknown. Preparations may include additional ingredients beyond Banisteriopsis caapi and DMT-containing plants.
  • Beta-carbolines in the brew may interact with certain foods, medications, or drugs. Harmala alkaloids inhibit monoamine oxidase (MAO), an enzyme present in the gastrointestinal tract that degrades monoamines.
  • The combination of MAOIs with SSRIs (selective serotonin reuptake inhibitors) or other serotonergic medications is contraindicated.

Psychological risks related to the nature of the experience

  • The primary risk associated with ayahuasca is the occurrence of a difficult psychological reaction.
  • The psychedelic effects can be intense and immersive. Fear or anguish may arise during the experience. These reactions are typically transient and resolve during or shortly after the session.
  • Adverse after-effects may occur, particularly if:
    • the experience was especially challenging
    • the setting was unsafe
    • adequate support was not provided during or after the session
  • Risks can be reduced by working with responsible and experienced guides and facilitators and by ensuring proper preparation and integration support.

 

Adverse Effects

Common adverse effects (or desired effects?)

  • Nausea and vomiting are the most common physical effects3.
  • In traditional Amazonian medicine, these effects are not considered adverse reactions but part of a therapeutic process known as la purga (“the purge”)4.
  • For many Indigenous practitioners, purging is a desired effect associated with physical, emotional, and energetic cleansing4.
  • In a sample of 614 participants, the most frequently reported effects were vomiting, nausea, and diarrhea. These were generally interpreted as part of a necessary cleansing process rather than harmful reactions5.

 

Adverse Reactions

Acute psychological adverse reactions

  • Psychiatric symptomatology among ayahuasca users appears to be rare and below general population prevalence. Nevertheless, ayahuasca is contraindicated for individuals with severe psychiatric disorders, particularly those prone to psychosis7.
  • A recent study found that 17.5% of first-time users meeting criteria for mental health disorders experienced “intense challenging psychological effects.” None developed persistent psychiatric symptoms or long-term negative consequences. Nearly half showed improvements. The authors concluded that challenging experiences may have positive long-term outcomes, including reduction in diagnostic criteria for certain disorders8.
  • Psychological challenges during an ayahuasca session are not, in themselves, evidence of psychopathology nor predictive of lasting psychiatric harm. With proper integration and support, participation may produce long-term beneficial effects.

For many participants, overcoming emotional and psychological challenges is central to the therapeutic value of the experience.

Addiction

Is ayahuasca addictive?

  • Ayahuasca does not produce dependence (i.e., it is not addictive)9.
  • Studies with healthy volunteers indicate that ayahuasca does not produce tolerance; increasing doses are not required to achieve similar effects.
  • The emetic (vomiting) effects also limit the risk of overuse.
  • Ayahuasca use appears to act as a protective factor regarding harmful alcohol and drug consumption.
  • Lower prevalence of alcohol and drug misuse has been observed among ayahuasca users14.

What about its potential for abuse?

  • Available evidence suggests ayahuasca may have potential in the treatment of substance dependence11.
  • Several clinics in South America specialize in addiction treatment using ayahuasca12.
  • Observational and qualitative studies across different cultural settings have reported promising outcomes13.
  • Neuroimaging studies in healthy volunteers show no activation of brain reward pathways typically associated with addictive substances10.

 

References and Resources

References

  1. Riba, 2003; dos Santos, 2011.
  2. McKenna, 2004.
  3. Callaway et al., 1999; Riba et al., 2001; Riba, 2003; Riba & Barbanoj, 2005; dos Santos, 2011; dos Santos et al., 2012.
  4. Luna, 1986, 2011.
  5. Durante et al., 2020.
  6. Mello et al., 2019.
  7. Lima & Tófoli, 2011; dos Santos & Strassman, 2011.
  8. Gómez-Sousa et al., 2021.
  9. dos Santos et al., 2012.
  10. Riba et al., 2006; de Araujo et al., 2011.
  11. Bouso & Riba, 2014.
  12. Mabit, 2007.
  13. Fernández et al., 2015; Loizaga-Velder & Verres, 2014; Thomas et al., 2013; Talin & Sanabria, 2017; Apud & Romaní, 2017.
  14. Grob et al., 1996; Halpern et al., 2008; Fábregas et al., 2010; Doering-Silveira et al., 2005a.

Resources

For access to the referred research citations, and for more detailed information on the topics highlighted in this Fact Sheet, please visit the latest edition of the Ayahuasca Technical Report (PDF):
Ayahuasca Technical Report (PDF)

For general information about ayahuasca, its history of use, and legal status in various countries, please visit:
www.iceers.org/ayahuasca/

Bibliography

  • Apud, I., Romaní, O. (2017). Medicine, religion and ayahuasca in Catalonia. Considering ayahuasca networks from a medical anthropology perspective. International Journal of Drug Policy, 39: 28-36.
  • Bouso, J. C., and Riba, J. (2015). Ayahuasca and the treatment of drug addiction. In: Labate, B. C., and Cavnar, C. (Eds.): The Therapeutic Use of Ayahuasca. Berlin: Springer, pp. 95-109.
  • Callaway, J. C. (2005). Various alkaloid profiles in decoctions of Banisteriopsis caapi. Journal of Psychoactive Drugs, 37(2): 151-155.
  • de Araujo, D. B., Ribeiro, S., Cecchi, G. A., Carvalho, F. M., Sanchez, T. A., Pinto, J. P., de Martinis, B. S., Crippa, J. A., Hallak, J. E., and Santos, A. C. (2011). Seeing with the eyes shut: Neural basis of enhanced imagery following ayahuasca ingestion. Human Brain Mapping, 33(11): 2550-2560.
  • Doering-Silveira, E., Grob, C. S., Dobkin de Rios, M., Lopez, E., Alonso, L. K., Tacla, C., and da Silveira, D. X. (2005a). Report on psychoactive drug use among adolescents using ayahuasca within a religious context. Journal of Psychoactive Drugs, 37(2): 141-144.
  • dos Santos, R. G. (2011). Ayahuasca: Physiological and subjective effects, comparison with d-amphetamine, and repeated dose assessment. Doctoral thesis, Autonomous University of Barcelona, Barcelona. Available at: https://www.tdx.cat/handle/10803/83979.
  • dos Santos, R. G., and Strassman, R. (2011). Ayahuasca and psychosis. In: dos Santos, R. G. (Ed.): The Ethnopharmacology of Ayahuasca. Trivandrum: Transworld Research Network. Available at: https://www.iceers.org/en/ayahuasca-safety-profile/.
  • Durante, I., dos Santos, R. G., Bouso, J. C., and Hallak, J. E. (2020). Risk assessment of ayahuasca use in a religious context: Self-reported risk factors and adverse effects. Brazilian Journal of Psychiatry, S1516-44462020005037201.
  • Fábregas, J. M., González, D., Fondevila, S., Cutchet, M., Fernández, X., Barbosa, P. C., Alcázar-Córcoles, M. Á., Barbanoj, M. J., Riba, J., and Bouso, J. C. (2010). Assessment of addiction severity among ritual users of ayahuasca. Drug and Alcohol Dependence, 111(3): 257-261.
  • Fernández, X., dos Santos, R. G., Cutchet, M., Fondevila, S., González, D., Alcázar, M. Á., and Fábregas, J. M. (2014). Assessment of the psychotherapeutic effects of ritual ayahuasca use on drug dependency: A pilot study. In: Labate, B. C. & Canvar, C. (Eds): The Therapeutic Use of Ayahuasca, pp. 183-196.
  • Gómez-Sousa, M., Jiménez-Garrido, D. F., Oña, G., dos Santos, R. G., Hallak, J. E. C., Alcázar-Córcoles, M. Á., and Bouso, J. C. (2021). Acute psychological adverse reactions in first-time ritual ayahuasca users: A prospective case series. Journal of Clinical Psychopharmacology, 41(2): 163-171.
  • Grob, C. S., McKenna, D. J., Callaway, J. C., Brito, G. S., Neves, E. S., Oberlaender, G., Saide, O. L., Labigalini, E., Tacla, C., Miranda, C. T., Strassman, R. J., and Boone, K.B. (1996). Human psychopharmacology of hoasca, a plant hallucinogen used in ritual context in Brazil. Journal of Nervous and Mental Disease, 184(2): 86-94.
  • Halpern, J. H., Sherwood, A. R., Passie, T., Blackwell, K. C., and Ruttenber, A. J. (2008). Evidence of health and safety in American members of a religion who use a hallucinogenic sacrament. Medical Science Monitor, 14(8): SR15-22.
  • Lima, F. A. S., and Tófoli, L. F. (2011). An epidemiological surveillance system by the UDV: Mental health recommendations concerning the religious use of hoasca. In: Labate, B. C., and Jungaberle, H. (Eds.): The Internationalization of Ayahuasca. Zurich/Berlin: LIT Verlag.
  • Loizaga-Velder, A., and Verres, R. (2014). Therapeutic effects of ritual ayahuasca use in the treatment of substance dependence – qualitative results. Journal of Psychoactive Drugs, 46(1): 63-72.
  • Luna, L. E. (1986a). Vegetalismo shamanism among the mestizo population of the Peruvian Amazon. Stockholm Studies in Comparative Religion #27. Stockholm: Almqvist and Wiksell International.
  • Luna, L. E. (2011). Indigenous and mestizo use of ayahuasca: An overview. In: dos Santos, R. G. (Ed.): The Ethnopharmacology of Ayahuasca. Trivandrum: Transworld Research Network. Available at: https://www.iceers.org/en/ayahuasca-safety-profile/.
  • Mabit, J. (2007). Ayahuasca in the treatment of addictions. In: Winkelman, M. J., and Roberts, T. B. (Eds.): Psychedelic Medicine: New Evidence for Hallucinogenic Substances as Treatments, vol. 2. Westport: Praeger.
  • McKenna, D. J. (2004). Clinical investigations of the therapeutic potential of ayahuasca: Rationale and regulatory challenges. Pharmacology and Therapeutics, 102(2): 111-129.
  • Mello, S. M., Soubhia, P. C., Silveira, G., Corrêa-Neto, N. F., Lanaro, R., Costa, J. L., and Linardi, A. (2019). Effect of ritualistic consumption of ayahuasca on hepatic function in chronic users. Journal of Psychoactive Drugs, 51(1): 3-11.
  • Riba, J. (2003). Human pharmacology of ayahuasca. Doctoral thesis, Autonomous University of Barcelona, Barcelona. Available at: https://www.tdx.cat/handle/10803/5378.
  • Riba, J., and Barbanoj, M. J. (2005). Bringing ayahuasca to the clinical research laboratory. Journal of Psychoactive Drugs, 37(2): 219-230.
  • Riba, J., and Barbanoj, M. J. (2006). Ayahuasca. In: Peris, J. C., Zurián, J. C., Martínez, G. C., and Valladolid, G. R. (Eds.): Tratado SET de Transtornos Adictivos. Madrid: Ed. Médica Panamericana.
  • Riba, J., Rodríguez-Fornells, A., Urbano, G., Morte, A., Antonijoan, R., Montero, M., Callaway, J. C., and Barbanoj, M. J. (2001). Subjective effects and tolerability of the South American psychoactive beverage ayahuasca in healthy volunteers. Psychopharmacology, 154(1): 85-95.
  • Riba, J., Valle, M., Urbano, G., Yritia, M., Morte, A., and Barbanoj, M. J. (2003). Human pharmacology of ayahuasca: Subjective and cardiovascular effects, monoamine metabolite excretion, and pharmacokinetics. Journal of Pharmacology and Experimental Therapeutics, 306(1): 73-83.
  • Riba, J., Romero, S., Grasa, E., Mena, E., Carrió, I., and Barbanoj, M. J. (2006). Increased frontal and paralimbic activation following ayahuasca, the pan-amazonian inebriant. Psychopharmacology, 186(1): 93-98.
  • Talin, P., and Sanabria, E. (2017). Ayahuasca’s entwined efficacy: An ethnographic study of ritual healing from ‘addiction’. International Journal of Drug Policy, 44: 23-30.
  • Thomas, G., Lucas, P., Capler, N. R., Tupper, K. W., and Martin, G. (2013). Ayahuasca-assisted therapy for addiction: Results from a preliminary observational study in Canada. Current Drug Abuse Reviews, 6(1): 30-42.