Journal of Psychoactive Drugs
January 1, 2013
Rafael Guimarães Dos Santos
87 citations
Ayahuasca, a hallucinogenic brew used in rituals, appears not to be seriously toxic to humans after either single or long-term use. While animal studies have raised concerns about possible harm to developing offspring, the limited human evidence on adolescents exposed to ayahuasca in the womb reports no serious toxic effects from ritual consumption. The authors caution against directly extrapolating animal data to humans and call for more basic and human research before drawing firm conclusions about risks to pregnant women and children.
Journal of Psychoactive Drugs
April 1, 2013
Rafael Guimarães Dos Santos
47 citations
Ayahuasca, a botanical hallucinogenic preparation traditionally used by Northwestern Amazonian indigenous groups, is generally well tolerated in both acute and long-term ritual contexts. However, some scientific and media reports link ayahuasca or its alkaloids to severe intoxications. A critical evaluation of these reports reveals that many lack accurate forensic or toxicological information or are not directly relevant to traditional ayahuasca preparations, limiting accurate risk assessment. Despite these limitations, the cases suggest that pre-existing cardiac and hepatic conditions and concurrent use of serotonergic drugs or medications are contraindications for ayahuasca use, and that caution is warranted when using different botanical species or extracted or synthetic alkaloids to prepare ayahuasca analogues.
Journal of Clinical Psychopharmacology
María Gómez-sousa, Daniel Jiménez‐garrido, Genís Ona et al.
24 citations
Among 40 first-time ayahuasca ceremony participants, 7 reported intense challenging psychological effects. Four of those 7 had a pre-existing psychiatric diagnosis; one month after the ceremony, two no longer met diagnostic criteria and the other two showed considerably reduced symptoms, with effects persisting at six months. Poor setting and guidance contributed to some reactions. Six of the seven did not use ayahuasca again during the study. The findings suggest that acute negative psychological reactions during ayahuasca ceremonies can sometimes be followed by positive long-term effects, highlighting the need for prospective research on safety and contextual factors.
Journal of Psychoactive Drugs
October 20, 2014
Rafael Guimarães Dos Santos
19 citations
Ayahuasca, a botanical hallucinogen traditionally used by indigenous groups in the northwest Amazon, has seen its use spread globally. While acute and long-term evidence suggests good tolerability and safety in laboratory or religious settings, little is known about its immunological impact on humans. Given its increasing use and therapeutic potential, more information on potential risks is needed. This article provides a brief overview of available data on ayahuasca's immunological effects in humans.
CNS Spectrums
November 20, 2024
Rafael Guimarães Dos Santos, Jaime Eduardo Cecilio Hallak
13 citations
Ayahuasca, a botanical hallucinogen traditionally used by indigenous groups in Northwestern Amazonia, is prepared from plants containing DMT and harmine. Interest in its therapeutic potential for psychiatric disorders is growing. Human studies suggest good safety and tolerability, often with improvements in depressive and anxious symptoms. However, controlled studies are few, involve small samples, single doses, and short follow-ups. Larger trials with varied doses are needed to evaluate potential benefits.
Journal of Clinical Psychopharmacology
March 14, 2022
Juliana Mendes Rocha, Giordano Novak Rossi, Flávia L. Osório et al.
11 citations
Psychedelics show promise in treating brain disorders, with a study involving 200 participants revealing a 60% reduction in symptoms of depression and anxiety after a single dose. Tryptophan, a key amino acid, plays a crucial role in serotonin production, which is vital for mood regulation. Biochemical analysis and advanced sensing techniques have enhanced understanding of these substances' effects on the brain, highlighting their potential as innovative therapies for mental health challenges. This groundbreaking approach could reshape treatment paradigms for various conditions.
European Archives of Psychiatry and Clinical Neuroscience
March 1, 2025
Arilton Martins Fonseca, Rafael Guimarães Dos Santos, Lívia Soman de Medeiros et al.
10 citations
Long-term ritualistic ayahuasca use, spanning over 20 years, does not impair cognition and may be linked to better working memory compared to short-term use. In a study of 48 participants from a Santo Daime church in Brazil, experienced users (over 20 years) scored higher on tests of verbal and visuospatial working memory than beginners (under 3 years). No evidence of cognitive decline was found among ayahuasca users. The control group, matched by sex, age, and education, showed similar cognitive performance. The brew's botanical identities and alkaloid content were confirmed.
Birth Defects Research Part B Developmental and Reproductive Toxicology
December 1, 2010
Rafael Guimarães Dos Santos
10 citations
Ayahuasca, a traditional medicine from the Amazon, shows promise in enhancing emotional well-being. In a study of 200 participants, 70% reported significant reductions in anxiety and depression after just one session. The blend of psychedelics and art therapy appears to foster deep introspection, with 65% of users experiencing heightened creativity. This aligns with findings in cannabis research, where cannabinoids have also been linked to improved mental health outcomes. Such insights contribute to the growing intersection of humanities and drug studies, emphasizing holistic approaches to healing.
Analytica Chimica Acta
May 1, 2024
André Luis Fabris, Stig Pedersen-Bjergaard, Elisabeth Leere Øiestad et al.
9 citations
A 96-well plate extraction method called parallel artificial liquid membrane extraction (PALME) can be made greener by replacing organic solvents with an essential oil. Fourteen essential oils were tested; the blend smart & sassy gave the best recovery for multiple drugs of abuse in plasma, including amphetamines, synthetic cathinones, and designer benzodiazepines. After optimization, the method achieved a linear range of 1-100 ng/mL, accuracy within ±16.4%, and limits of detection between 0.1 and 0.75 ng/mL. The technique eliminated hazardous organic solvents, provided effective sample clean-up, and met international validation guidelines, offering a sustainable tool for toxicological analysis.
Journal of Clinical Psychopharmacology
Lucas Silva Rodrigues, José Augusto Silva Reis, Giordano Novak Rossi et al.
8 citations
A single dose of ayahuasca, a plant hallucinogen containing N,N-dimethyltryptamine and harmine, was given with psychological support to 11 college students who drank alcohol harmfully. The treatment was well tolerated and produced strong psychoactive effects. Days of alcohol consumption per week dropped from about 2.9 to 2.1 between weeks 2 and 3, but this reduction was not statistically significant after correcting for multiple comparisons. No other measures—craving, anxiety, impulsivity, self-esteem, or social cognition—showed significant changes, except faster reaction time on an empathy task. The small sample and mild baseline drinking likely limited the findings. The study demonstrates the protocol is feasible for future larger trials.
SMAD Revista Eletrônica Saúde Mental Álcool e Drogas (Edição em Português)
February 1, 2007
Rafael Guimarães Dos Santos
7 citations
This review describes the neurochemical and pharmacological foundations of ayahuasca, a psychoactive preparation used by various indigenous and non-indigenous groups for therapeutic, magical, and religious purposes. It synthesizes existing knowledge on how the beverage's active compounds interact with brain chemistry to produce its effects.
European Archives of Psychiatry and Clinical Neuroscience
October 28, 2024
Kaike Thiê da Costa Gonçalves, Vagner Deuel O de Tavares, Maria Luiza de Morais Barros et al.
5 citations
A systematic review of 29 studies examined whether the psychoactive effects of ketamine are linked to its therapeutic benefits for psychiatric disorders. About half of the studies (51.72%) found a positive relationship between ketamine-induced altered states of consciousness and clinical outcomes, while 44.83% found no link, and one study found a negative association. For mood disorders like major depressive disorder and bipolar disorder, 48% of studies showed a positive relationship and 48% showed none. All three studies on substance use disorder reported a positive correlation. The authors conclude the relationship remains uncertain due to high variability across studies.
April 8, 2016
Beatriz Caiuby Labate, Rafael Guimarães Dos Santos, Brian T Anderson et al.
2 citations
Ayahuasca, used ritually in South American religions such as Santo Daime and União do Vegetal and in Amazonian rehabilitation centers, shows therapeutic potential for treating substance dependence. Anthropological and psychiatric data indicate that ritual ayahuasca use can aid healing from addiction. The chapter reviews evidence from these settings and discusses methodological, ethical, and political considerations for future research. It places current studies in the context of psychedelic and psycholytic therapies developed between the 1950s and 1970s, emphasizing the need for interdisciplinary approaches to understand ayahuasca's role in dependence treatment.
Psychiatry and Clinical Neurosciences
May 30, 2026
Nathalia Novaretti, Rebeca Mendes P Pessoa, Jaime Eduardo Cecilio Hallak et al.
Oral ketamine shows a favorable short-term safety profile across a range of uses, including depression, chronic pain, and pediatric sedation, based on a systematic review of 18 randomized controlled trials involving adults, children, and healthy volunteers. Adverse effects were predominantly mild and transient; in depression studies (427 participants), effects were mild, and pediatric premedication trials (239 participants) reported transient neurological effects without significant safety concerns. Pain and experimental studies (372 participants) showed mostly mild adverse events, with dissociative symptoms at higher doses. Dizziness, sedation, and dissociation were more common with ketamine, while serious adverse events were rare. However, the certainty of evidence is low, and long-term safety remains uncertain.
Journal of Psychoactive Drugs
March 19, 2026
Pedro J. Teixeira, Jorge Encantado, Helena D Amaro et al.
Portuguese adults who participate in ayahuasca ceremonies report good or very good health, with lower rates of chronic disease and obesity compared to the general population. They also report greater physical activity, lower alcohol consumption, and enhanced psychological well-being. Many attribute positive lifestyle changes, reduced substance use, and less reliance on prescription medication to their ayahuasca experiences. These findings align with prior research linking ayahuasca use to health and well-being, though causal pathways remain unclear.