Intensity of Mystical Experiences Occasioned by 5-MeO-DMT and Comparison With a Prior Psilocybin Study, Joseph Barsuglia et al., 2018

Intensity of Mystical Experiences Occasioned by 5-MeO-DMT and Comparison With a Prior Psilocybin Study

Joseph Barsuglia, Alan K. Davis, Robert Palmer, Rafael Lancelotta, Austin-Marley Windham-Herman, Kristel Peterson, Martin Polanco, Robert Grant and Roland R. Griffiths

Frontiers in Psychology, 2018, Vol 9, Article

doi : 10.3389/fpsyg.2018.02459


5-MeO-DMT is a psychoactive substance found in high concentrations in the bufotoxin of the Colorado River Toad (Bufo alvarius). Emerging evidence suggests that vaporized 5-MeO-DMT may occasion mystical experiences of comparable intensity to those occasioned by more widely studied psychedelics such as psilocybin, but no empirical study has tested this hypothesis. Data was obtained from 20 individuals (Mage = 38.9,  10.7; male = 55%, Caucasian = 85%) who were administered 5- MeO-DMT as part of a psychospiritual retreat program in Mexico. All participants received 50 mg of inhaled vaporized toad bufotoxin which contains 5-MeO-DMT and completed the Mystical Experience Questionnaire (MEQ30) approximately 4–6 h after their session. Administration of 5-MeO-DMT occasioned strong mystical experiences (MEQ30 Overall Mintensity = 4.17,  0.64, range 0–5) and the majority (n = 15, 75%) had “a complete mystical experience” (60% on all MEQ30 subscales). Compared to a prior laboratory-based psilocybin study, there were no differences in the intensity of mystical effects between 5-MeO-DMT and a high dose (30 mg/70 kg) of psilocybin, but the intensity of mystical effects was significantly higher in the 5-MeO-DMT sample compared to moderate/high dose (20 mg/70 kg) of psilocybin (MEQ30 Total Score: p = 0.02, d = 0.81). Administration of vaporized 5-MeO-DMT reliably occasioned complete mystical experiences in 75% of individuals and was similar in intensity to high
dose psilocybin administered in a laboratory setting. The short duration of action may be advantageous for clinical interventions and for studying mystical-type experiences.

Keywords : 5-MeO-DMT, tryptamines, psychedelic, mystical experience, DMT, Bufo alvarius, Colorado river toad



5-Methoxy-N,N-dimethyltryptamine (5-MeO-DMT) is a psychoactive indolealkylamine (Yu, 2008;
Szabo et al., 2014) that is present in the bufotoxin of the Colorado River toad (Bufo alvarius) (Weil
and Davis, 1994; Lyttle et al., 1996), numerous plant species (Smith, 1977; Ott, 2001; Shulgin and
Shulgin, 2002), and can be synthetically produced (Hoshino and Shimodaira, 1936). Preliminary evidence shows that 5-MeO-DMToccasions mystical experiences (Davis et al., in press) similar in intensity to those occasioned by psilocybin (Griffiths et al., 2011), with a much shorter duration of action (half-life 12–19 min; Shen et al., 2010). Mystical experiences occasioned by psilocybin are a primary predictor of therapeutic outcomes in patients with substance use disorders (Garcia-Romeu et al., 2014; Bogenschutz et al., 2015) and depression/anxiety (Cowen, 2016; Griffiths et al., 2016). Such experiences are reported as profoundly meaningful, spiritual and transformative peak life events, and are associated with adaptive outcomes across a range of psychological domains (Griffiths et al., 2018; Roseman et al., 2018). However, the lack of laboratory-based studies examining the dose-related effects of 5-MeO-DMT in humans limits our understanding of this substance. Furthermore, no published studies have directly compared the intensity of mystical experiences occasioned by 5-MeO-DMT to psilocybin administered in the laboratory.

The current study aimed to address this gap in the literature via two primary aims. The first aim was to examine the intensity of mystical experiences following administration of 5-MeO-DMT (in the form of vaporized bufotoxin) to participants in a residential psychospiritual retreat. We hypothesized that these participants would rate the intensity of mystical effects as moderate-to-strong, similar to the prior findings for 5-MeO-DMT users in a survey study (Davis et al., 2018; Davis et al., in press). The second aim was to compare the intensity of mystical experiences occasioned by 5-MeO-DMT in the present study with that recorded in a prior laboratory-based psilocybin study (Griffiths et al., 2011). We hypothesized that the intensity of mystical experiences would be similar to that reported by individuals
administered high-dose psilocybin and greater than that reported by individuals administered a moderate/high dose of psilocybin.



All 20 participants (11 males) were residents of a psychospiritual retreat at a center in Baja California, Mexico, between August 2015 and May 2017. They were medically healthy as determined by medical examination and history, electrocardiography, and urine drug testing. Participants had an average age of 38 years (range, 21–57 years). Eight participants (40% of the sample) had a college degree, five (25%) had a graduate degree, and three (15%) had a high school diploma. Seventeen participants (85%) reported their ethnicity as White/Caucasian; one (5%) Asian; one (5%) Latino or Hispanic; and one (5%) other.

Sixteen of the participants (80%) were from the United States; two (10%) from Canada; and two (10%) from Australia and New Zealand. Nine participants (45%) reported having a religious affiliation that included three (15%) affiliated with Christianity, two (10%) with inter/non-denominational faith, two (10%) with Hinduism, one (5%) with Judaism, and one (5%) with Buddhism.


At the center, all residents were accepted into the fourday retreat program on a fee-for-service basis that included administration of vaporized 5-MeO-DMT and therapeutic preparation, education, and integration. Each resident received 50 mg of vaporized bufotoxin, estimated to contain 5–7 mg of 5-MeO-DMT (5-MeO-DMT content of 10–15%, considered a “light” to “common” dose) (Weil and Davis, 1994; Metzner, 2013; Erowid, 2017). The bufotoxin was obtained from wild toads in the Sonoran Desert, Mexico. The bufotoxin was kept in a glass vial attachment of an Eclipse (Herbal, 2016) handheld
vaporizer and heated with a torch lighter to the point of vaporization of all contents. As soon as vapors began to be emitted, residents were instructed to fully exhale and then slowly fill their lungs to capacity and hold the full inhalation for a minimum of 10s. At the end of 10s, the facilitator guided residents to exhale and lay down. A medical doctor and facilitator/guide were present during the session. Within 4–6 h following their experience, residents were given the option to complete the Mystical Experience Questionnaire (described below) as part of a brief anonymous exit program evaluation and satisfaction survey on an online survey platform1. Of the 76 residents who completed the exit survey, 20 opted to complete the questionnaire (26.3% completion rate). No identifiable data was collected and the survey was stored in a secured database separate from clinic records.