Neural Effects of Intravenous N,N-dimethyltryptamine (DMT)

Neural Effects of Continuous Intravenous Infusion of N,N-dimethyltryptamine (DMT)

This study examines how the psychedelic substance DMT affects the human brain when administered by the intravenous (IV) route. DMT is a naturally occurring chemical in the body that is thought to help improve mood when ingested in a continuously monitored medical setting. Previous research has shown that a single IV injection of DMT can be given safely, but its effects, which include changes in perception, emotions, and thinking, usually wear off within 15-20 minutes.

To better understand what happens when DMT's effects last longer, researchers have developed a method to give DMT slowly and continuously through an IV, which safely extends its effects for up to an hour or more. In this study, healthy volunteers who have prior experience using DMT will receive low and medium doses of DMT in this extended manner through an IV for 1 hour while undergoing a brain scanning technique known as functional magnetic resonance imaging (fMRI). These scans allow researchers to see changes in brain activity and blood flow in real time.

Participants will complete psychological assessments before and after receiving DMT, and additional brain scans without DMT will be used for comparison. The researchers will also use advanced computer techniques to help identify brain patterns linked to the visual experiences people report during DMT.

Overall, the goal of the study is to better understand how DMT affects the brain during an extended experience and to learn more about the biological processes behind its psychological effects.

Study Overview

• Status: Not yet recruiting
• Conditions: Healthy Participants Study
• Intervention / Treatment: Drug: N,N-Dimethyltryptamine (15 mg); Drug: N,N-Dimethyltryptamine (17.5 mg)

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Yasmeen Esshaki; Phone Number: 619-786-0375; Email: deanlaboratory@health.ucsd.edu

Study Locations

• United States
  • California
    • La Jolla, California, United States, 92037
      • Altman Clinical and Translational Research Institute
      • Principal Investigator: Jon Dean, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 18 to 65 years of age
• Able to fluently communicate in English
• Agree to sign the consent and HIPAA authorization
• Not taking serotonergic antidepressant medication
• Willing to refrain from using any non-prescribed psychoactive drugs, including alcohol, within 24 hours before and after study drug administration
• Willing to refrain from consumption of illicit psychoactive substances during the study
• Agree not to use any nonprescription medications, herbal medications, or supplements during the week prior to each drug session unless an exception is approved by the study investigators
• Willing to refrain from smoking or use of nicotine from 8:00 AM on the morning of drug sessions until discharge at the end of the session
• Have used classic serotonergic hallucinogens (e.g., LSD, psilocybin mushrooms, ayahuasca) without untoward/adverse effects and report "liking" psychedelic drugs with no previous adverse reactions to DMT or other psychedelics
• Report at least 20 lifetime uses of psychedelics, including at least 5 uses of DMT (any form), at least one via inhalation, at least once within the past 2 years, and not within the past 3 months
• Able to remain in an fMRI scanner without sedation and pass fMRI safety screening
• Refrain from caffeine use prior to fMRI scanning
• Women of childbearing potential must agree to use effective birth control from screening through the final visit
• Have a relative or friend available to provide transportation after the drug session
• Not taking medications acting as serotonin antagonists (e.g., cyclobenzaprine, ondansetron), dopamine antagonists (e.g., metoclopramide, promethazine, prochlorperazine), dopamine agonists (e.g., levodopa, pramipexole, apomorphine), psychostimulants (e.g., modafinil, armodafinil, solriamfetol, methylphenidate, dexmethylphenidate, atomoxetine, dextroamphetamine, mixed amphetamine salts, lisdexamfetamine), anticholinergics (e.g., benztropine, trihexyphenidyl, scopolamine, hyoscyamine), or NMDA receptor antagonists (e.g., amantadine, memantine, ketamine)

Exclusion Criteria:

• Pregnant or nursing females
• Females of childbearing potential who are sexually active but not using birth control
• MRI contraindications (e.g., pacemakers, metal implants, spinal cord stimulators)
• Current DSM-5 diagnosis of depression or anxiety (or within past 6 months), bipolar disorder, schizophrenia, or other psychotic disorder
• First-degree relative with bipolar disorder, schizophrenia, or other psychotic disorder
• Suicide risk as determined by clinician assessment and/or C-SSRS
• Active substance use disorder (excluding tobacco and caffeine)
• Use of serotonergic dietary supplements (e.g., 5-hydroxytryptophan, St. John's wort, SAM-e) if unwilling to discontinue for study duration
• Neurological conditions affecting cognition or perception (e.g., dementia, traumatic brain injury, mild cognitive impairment)
• Positive urine drug screen for amphetamines, barbiturates, buprenorphine, cocaine, methamphetamine, MDMA, methadone, opiates, or phencyclidine
• Use of DMT or another serotonergic hallucinogen within the past 3 months
• Concomitant treatment with antipsychotic medications
• Concomitant treatment with antidepressants, MAO inhibitors, or serotonin reuptake inhibitors (trazodone ≤50 mg/day for insomnia allowed but not within 48 hours of DMT session)
• Severe hearing or visual impairment
• History of seizure disorder or epilepsy
• History of adverse reactions to rescue medications used in the study (benzodiazepines, antipsychotics, labetalol, nitroglycerin, ondansetron)
• Cardiovascular disease or hypertension (SBP >140 mmHg or DBP >90 mmHg)
• Resting heart rate >90 bpm
• Hypotension (SBP <90 mmHg or DBP <60 mmHg)
• QTc prolongation (>0.045 sec for men, >0.047 sec for women)
• History of stroke, angina, clinically significant ECG abnormality, or artificial heart valve
• Severe renal impairment (GFR <30 mL/min/1.73 m²)
• Clinically significant laboratory abnormalities
• History of syncope
• History of vertigo
• Myocardial infarction within 12 months
• Child-Pugh class B or higher, or with alanine aminotransferase or aspartate aminotransferase >2x upper limit of normal
• Concomitant medications associated with serotonin syndrome (e.g., carbamazepine, dextromethorphan, lithium, linezolid, buspirone)
• Severely compromised hepatic function
• Trypanophobia (fear of needles/blood)
• Treatment with another investigational drug within 30 days of screening

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: DMT hemifumarate "low" dose; Participants will be randomized to receive, in a double-blinded, counter-balanced, and crossover design, two doses of IV DMT during fMRI scanning delivered within two weeks apart under the care of a study physician.	Drug: N,N-Dimethyltryptamine (15 mg); Participants will receive one "low" dose (15 mg for 1 min + 1.5 mg/min for 59 min) of synthetic DMT (hemifumarate) via IV injection.
Experimental: DMT hemifumarate "medium" dose; Participants will be randomized to receive, in a double-blinded, counter-balanced, and crossover design, two doses of IV DMT during fMRI scanning delivered within two weeks apart under the care of a study physician.	Drug: N,N-Dimethyltryptamine (17.5 mg); Participants will receive one "medium" dose (17.5 mg for 1 min + 1.75 mg/min for 59 min) of synthetic DMT (hemifumarate) via IV injection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
fMRI - Blood Oxygen Level Dependent (BOLD) Signaling	Whole brain BOLD fMRI acquired during the peak subjective effects of IV administration of two separate doses ("low" and "medium") of DMT hemifumarate over a 60 min period for comparison across time, between dose, and versus rest/saline infusion.	Up to 3 months: Assessed at baseline fMRI (Visit 2) and dosing fMRI (Visits 6, 8).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Numeric Rating Sale for current anxiety and pain, and feelings of compassion toward oneself and other	Likert scale ranging from 0 to 10, with higher scores indicating higher anxiety, pain, and compassion, respectively	Up to 4 months: Assessed at baseline fMRI (Visit 2), dosing fMRI (Visits 6, 8), integration (Visits 7, 9), and follow-up (Visits 10, 11, 12)
Numeric Rating Sale for current mood and stress	Likert scale ranging from 0 to 10, with higher scores endorsing the feeling of being more upset and more stress, respectively	Up to 6 months: Assessed at baseline (Visit 2), dosing fMRI (Visits 6, 8), integration (Visits 7, 9), follow-up (Visits 10, 11, 12), and post-dosing fMRI (Visits 13, 14, 15)
Numeric Rating Scale for immersion, visual effects, distortion in time perception, good and bad drug effects, drug intensity, and entity phenomena experienced	Likert scale ranging from 0 to 10, with higher scores indicating higher endorsement of respective constructs	Up to 3 months: Assessed at baseline fMRI (Visit 2), and dosing fMRI (Visits 6, 8)
Hallucinogen Rating Scale	Measures the acute subjective effects of hallucinogenic drugs across six domains: intensity, somaesthesia, affect, perception, cognition, and volition. Participants rate 100 items on a 5-point Likert scale (0-4), and domain scores are calculated as the mean of items within each domain, with higher scores indicating greater intensity of psychedelic effects	Up to 3 months: Assessed at baseline fMRI (Visit 2), and dosing fMRI (Visits 6, 8)
Autonomous Entity Questionnaire	Measures the presence and characteristics of perceived autonomous entities encountered during altered states of consciousness. Participants rate items assessing occurrence, emotional valence, perceived agency, and interaction with entities on Likert scales (0-100), with higher scores indicating stronger or more elaborate entity experiences	Up to 3 months: Assessed at baseline fMRI (Visit 2), and dosing fMRI (Visits 6, 8)
State Anxiety Inventory	Measures current (state) anxiety using 20 self-report items rated on a 4-point Likert scale (1-4). Total scores range from 20 to 80, with higher scores indicating greater state anxiety.	Up to 4 months: Assessed at baseline fMRI (Visit 2), dosing fMRI (Visits 6, 8), integration (Visits 7, 9), and follow-up (Visits 10, 11, 12)
End of Day Questionnaire	Measures participants' overall experience following study drug administration, including perceived drug effects, adverse events, mood, and general well-being. Responses are collected using Likert scales (typically 0-10 or 1-5 depending on the item), and individual items are analyzed rather than a composite total score	Up to 3 months: Assessed at dosing fMRI (Visits 6, 8)
11-Dimensional Altered States of Consciousness Questionnaire	Measures multiple dimensions of altered conscious experience, including unity, insightfulness, bliss, disembodiment, anxiety, and visual alterations. Participants rate 42 items on visual analog scales ranging from 0 to 100, and scores are calculated separately for each of the 11 dimensions, with higher scores indicating greater intensity of each experience	Up to 3 months: Assessed at baseline fMRI (Visit 2), and dosing fMRI (Visits 6, 8)
Challenging Experiences Questionnaire	Measures psychologically difficult experiences during psychedelic administration across domains including fear, grief, paranoia, insanity, isolation, death, and physical distress. Participants rate 26 items on a 6-point scale (0-5), and domain scores are calculated as mean item scores, with higher scores indicating more intense challenging experiences	Up to 3 months: Assessed at baseline fMRI (Visit 2), and dosing fMRI (Visits 6, 8)
Persisting Effects Questionnaire	Measures long-term perceived changes attributed to the psychedelic experience, including changes in attitudes, mood, behavior, relationships, spirituality, and well-being. Participants rate positive and negative changes on Likert scales (-3 to +3 or 0-5), with higher positive scores reflecting greater beneficial persisting effects	Up to 4 months: Assessed at baseline fMRI (Visit 2), dosing fMRI (Visits 6, 8), integration (Visits 7, 9), and follow-up (Visits 10, 11, 12)
Visual Effects Questionnaire	Measures the intensity and frequency of visual phenomena experienced during altered states, including geometric imagery, color enhancement, motion, patterning, and visual distortions. Participants rate items on visual analog scales ranging from 0 to 100, with higher scores indicating greater visual alterations	Up to 4 months: Assessed at baseline fMRI (Visit 2), dosing fMRI (Visits 6, 8), integration (Visits 7, 9), and follow-up (Visits 10, 11, 12)
Vividness of Visual Imagery Questionnaire	Measures the vividness of voluntarily generated mental imagery across everyday visual scenarios. Participants rate 16 items on a 5-point scale (1-5). Total scores range from 16 to 80, with higher scores indicating more vivid visual imagery	Up to 4 months: Assessed at baseline fMRI (Visit 2), dosing fMRI (Visits 6, 8), integration (Visits 7, 9), and follow-up (Visits 10, 11, 12)
Pittsburgh Sleep Quality Index	Measures subjective sleep quality across seven components including sleep duration, latency, efficiency, disturbances, medication use, and daytime dysfunction. Component scores (0-3) are summed to produce a global score ranging from 0 to 21, with higher scores indicating poorer sleep quality	Up to 4 months: Assessed at baseline fMRI (Visit 2), dosing fMRI (Visits 6, 8), integration (Visits 7, 9), and follow-up (Visits 10, 11, 12)
Quick Inventory of Depressive Symptomatology	Measures the severity of depressive symptoms across nine DSM symptom domains using 16 self-report items rated from 0 to 3. Total scores range from 0 to 27, with higher scores indicating greater depression severity	Up to 4 months: Assessed at baseline fMRI (Visit 2), dosing fMRI (Visits 6, 8), and follow-up (Visits 10, 11, 12)
Five Facet Mindfulness Questionnaire	Measures trait mindfulness across five domains: observing, describing, acting with awareness, nonjudging of inner experience, and nonreactivity to inner experience. Uses a 5-point Likert scale (1-5). Total scores range from 39 to 195, with higher scores indicating greater mindfulness	Up to 4 months: Assessed at baseline fMRI (Visit 2), dosing fMRI (Visits 6, 8), integration (Visits 7, 9), and follow-up (Visits 10, 11, 12)
Montreal Cognitive Assessment	Measures global cognitive function across domains including attention, executive function, memory, language, visuospatial ability, abstraction, and orientation. Total scores range from 0 to 30, with higher scores indicating better cognitive performance	Up to 4 months: Assessed at baseline fMRI (Visit 2), integration (Visit 9), and follow-up (Visit 12)
Adverse events	Tracking all adverse and serious adverse events throughout study participant	Up to 6 months: Tracked across all study visits
Blood Pressure	Tracking blood pressure readings for >140/90 mmHg and <90/60 mmHg cutoffs	Up to 3 months: Assessed at screening (Visit 1), baseline fMRI (Visit 2), preparatory session (Visit 5), dosing fMRI (Visits 6, 8)
Heart Rate	Tracking heart rate for >90 bmp exclusion at screening and 110 bpm and (220 - age) * 0.85 bpm during dosing	Up to 3 months: Assessed at screening (Visit 1), baseline fMRI (Visit 2), preparatory session (Visit 5), dosing fMRI (Visits 6, 8)
Columbia Suicide Severity Rating Scale	Measures the severity of suicidal ideation and suicidal behavior through structured clinician-administered questions assessing the presence, intensity, frequency, duration, controllability, deterrents, and reasons for suicidal thoughts, as well as suicidal behaviors. Suicidal ideation severity is categorized on a 5-point scale (1-5) ranging from a wish to be dead (1) to active suicidal ideation with specific plan and intent (5), while suicidal behaviors are recorded as present or absent	Assessed at all study visits from enrollment through completion of the 4-week post-dosing follow-up (Visit 12)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Participant validation of BOLD fMRI-based visual decoding models	Machine learning-based diffusion models will be trained using participants' verbal reports of DMT visual phenomena and corresponding visual cortex BOLD fMRI activity obtained during dosing fMRI sessions. Additional post-dosing fMRI sessions, during which participants view Natural Scenes Dataset images and AI-generated images corresponding to their reported DMT visual imagery, will be used to train and optimize the decoding models. Participants will subsequently validate decoder-generated visual outputs by selecting the reconstructed image from sets containing distractor images and by rating how closely each reconstructed image matches the remembered DMT visual experience using a numeric rating scale (0 = no resemblance; 10 = exact resemblance). Higher scores indicate greater agreement between reconstructed and remembered visual imagery.	Up to 6 months: Assessed at dosing fMRI (Visits 6, 8) post-dosing fMRI (Visits 13, 14, 15), and validation (Visit 16)
Plasma levels of DMT, indole-3-acetic acid, and DMT-N-Oxide	Assessed 18 times on each study dosing visit via blood sampling	110 minutes
Salivary levels of DMT, indole-3-acetic acid, and DMT-N-Oxide	Assessed up to 3 times on each study dosing visit via saliva sampling	60 minutes
Plasma levels of cortisol, oxytocin, and BDNF	Assessed up to 18 times on each study dosing visit via blood sampling	110 minutes
Plasma levels of immune/inflammatory biomarkers [tumor necrosis factor-α (TNF-α), interleukin (IL)- 1β, IL-6, IL-18 and C-reactive protein (CRP)].	Assessed up to 18 times on each study dosing visit via blood sampling	110 minutes

Collaborators and Investigators

• Sponsor: Jon Dean
• Investigators: Principal Investigator: Jon Dean, PhD, UCSD

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): September 1, 2028
• Study Completion (Estimated): September 1, 2029

Study Registration Dates

• First Submitted: February 6, 2026
• First Submitted That Met QC Criteria: July 8, 2026
• First Posted (Actual): July 9, 2026

Study Record Updates

• Last Update Posted (Actual): July 9, 2026
• Last Update Submitted That Met QC Criteria: July 8, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Healthy; fMRI; Psychedelics; N,N-dimethyltryptamine; DMT; Intravenous DMT
• Additional Relevant MeSH Terms: Organic Chemicals; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Amines; Indoles; Biogenic Monoamines; Biogenic Amines; Tryptamines; N,N-Dimethyltryptamine
• Other Study ID Numbers: 812478

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No