Pharmacology of ayahuasca administered in two repeated doses
Rafael G. Dos Santos, Eva Grasa, Marta Valle, María Rosa Ballester, José Carlos Bouso, Josep Nomdedéu, R. Homs, Manel J. Barbanoj, Jordi Riba
Psychopharmacology August 12, 2011 DOI: 10.1007/s00213-011-2434-x (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Double-blind, crossover, placebo-controlled clinical trial Peer reviewed |
|---|---|
| Sample size | 9 |
| Population | Experienced psychedelic drug users |
| Interventions | Ayahuasca Lactose placebo |
| Dose | 0.75 mg DMT/kg bodyweight |
| Duration | 4-hour interval between doses, 12-hour total measurement period |
| Topics | Ayahuasca |
| Keywords | Placebo Crossover study Pharmacology Sensitization Prolactin Agonist |
| Citations | 139 |
| Key findings | No clear tolerance or sensitization in psychological or most physiological variables, but a trend to lower cardiovascular activation and significant tolerance to growth hormone secretion after repeated ayahuasca doses. |
Abstract
RationaleAyahuasca is an Amazonian tea containing the natural psychedelic 5-HT(2A/2C/1A) agonist N,N-dimethyltryptamine (DMT). It is used in ceremonial contexts for its visionary properties. The human pharmacology of ayahuasca has been well characterized following its administration in single doses.ObjectivesTo evaluate the human pharmacology of ayahuasca in repeated doses and assess the potential occurrence of acute tolerance or sensitization.MethodsIn a double-blind, crossover, placebo-controlled clinical trial, nine experienced psychedelic drug users received PO the two following treatment combinations at least 1 week apart: (a) a lactose placebo and then, 4 h later, an ayahuasca dose; and (b) two ayahuasca doses 4 h apart. All ayahuasca doses were freeze-dried Amazonian-sourced tea encapsulated to a standardized 0.75 mg DMT/kg bodyweight. Subjective, neurophysiological, cardiovascular, autonomic, neuroendocrine, and cell immunity measures were obtained before and at regular time intervals until 12 h after first dose administration.ResultsDMT plasma concentrations, scores in subjective and neurophysiological variables, and serum prolactin and cortisol were significantly higher after two consecutive doses. When effects were standardized by plasma DMT concentrations, no differences were observed for subjective, neurophysiological, autonomic, or immunological effects. However, we observed a trend to reduced systolic blood pressure and heart rate, and a significant decrease for growth hormone (GH) after the second ayahuasca dose.ConclusionsWhereas there was no clear-cut tolerance or sensitization in the psychological sphere or most physiological variables, a trend to lower cardiovascular activation was observed, together with significant tolerance to GH secretion.
Comparable studies
Other randomized controlled trials on ayahuasca, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression: a randomized placebo-controlled trial Patients with treatment-resistant depression | 2018 | Randomized controlled trial | n = 29 |
| Human Pharmacology of Ayahuasca: Subjective and Cardiovascular Effects, Monoamine Metabolite Excretion, and Pharmacokinetics Volunteers with prior experience in the use of psychedelics | 2003 | Double-blind placebo-controlled clinical trial | n = 18 |
| Subjective effects and tolerability of the South American psychoactive beverage Ayahuasca in healthy volunteers Healthy male volunteers with prior experience using ayahuasca | 2001 | Single-blind crossover placebo-controlled clinical trial | n = 6 |
| Increased frontal and paralimbic activation following ayahuasca, the pan-amazonian inebriant Male volunteers with prior experience in the use of psychedelics | 2006 | Randomized controlled trial | n = 15 |
| Human brain effects of DMT assessed via EEG-fMRI. Healthy volunteers | 2023 | Within-subjects, placebo-controlled design | n = 20 |
Citations in the library
Cited by 112
- Antidepressant effects of a single dose of ayahuasca in patients with recurrent depression: a preliminary report Brazilian Journal of Psychiatry March 1, 2015
- The Psychedelic State Induced by Ayahuasca Modulates the Activity and Connectivity of the Default Mode Network PLoS One February 18, 2015
- Adverse effects of psychedelics: From anecdotes and misinformation to systematic science. Journal of Psychopharmacology February 2, 2022
- Personality, Psychopathology, Life Attitudes and Neuropsychological Performance among Ritual Users of Ayahuasca: A Longitudinal Study PLoS One August 8, 2012
- Antidepressive, anxiolytic, and antiaddictive effects of ayahuasca, psilocybin and lysergic acid diethylamide (LSD): a systematic review of clinical trials published in the last 25 years Therapeutic Advances in Psychopharmacology March 18, 2016
and 107 more in the library
Cites 18
- Dose-Response Study of N,N-Dimethyltryptamine in Humans Archives of General Psychiatry February 1, 1994
- Monoamine oxidase inhibitors in South American hallucinogenic plants: Tryptamine and β-carboline constituents of Ayahuasca Journal of Ethnopharmacology April 1, 1984
- Human Pharmacology of Ayahuasca: Subjective and Cardiovascular Effects, Monoamine Metabolite Excretion, and Pharmacokinetics Journal of Pharmacology and Experimental Therapeutics June 18, 2003
- Subjective effects and tolerability of the South American psychoactive beverage Ayahuasca in healthy volunteers Psychopharmacology February 22, 2001
- The globalization of ayahuasca: Harm reduction or benefit maximization? International Journal of Drug Policy December 5, 2006
and 13 more in the library