Direct Comparison of Altered States of Consciousness Induced by LSD and Psilocybin (LSD-psilo)
![]() |
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT03604744 |
Recruitment Status :
Completed
First Posted : July 27, 2018
Last Update Posted : April 27, 2021
|
- Study Details
- Tabular View
- No Results Posted
- Disclaimer
- How to Read a Study Record
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Healthy | Drug: LSD Drug: Psilocybin | Early Phase 1 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 28 participants |
Allocation: | Randomized |
Intervention Model: | Crossover Assignment |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Primary Purpose: | Basic Science |
Official Title: | Direct Comparison of Altered States of Consciousness Induced by LSD and Psilocybin in a Random-order Placebo-controlled Cross-over Study in Healthy Subjects |
Actual Study Start Date : | March 27, 2019 |
Actual Primary Completion Date : | April 10, 2021 |
Actual Study Completion Date : | April 15, 2021 |

Arm | Intervention/treatment |
---|---|
Experimental: LSD-100, LSD-200, Psilocybin-15, Psilocybin-30, Placebo
Cross-over within-subjects design with all treatment conditions, separated by a wash-out phase
|
Drug: LSD
LSD 0.1 mg per os, single dose Drug: LSD LSD 0.2 mg per os, single dose Drug: Psilocybin Psilocybin 15 mg per os, single dose Drug: Psilocybin Psilocybin 30 mg per os, single dose |
Placebo Comparator: LSD-200, Psilocybin-15, Psilocybin-30, Placebo, LSD-100
Cross-over within-subjects design with all treatment conditions, separated by a wash-out phase
|
Drug: LSD
LSD 0.1 mg per os, single dose Drug: LSD LSD 0.2 mg per os, single dose Drug: Psilocybin Psilocybin 15 mg per os, single dose Drug: Psilocybin Psilocybin 30 mg per os, single dose |
Placebo Comparator: Psilocybin-15, Psilocybin-30, Placebo, LSD-100, LSD-200
Cross-over within-subjects design with all treatment conditions, separated by a wash-out phase
|
Drug: LSD
LSD 0.1 mg per os, single dose Drug: LSD LSD 0.2 mg per os, single dose Drug: Psilocybin Psilocybin 15 mg per os, single dose Drug: Psilocybin Psilocybin 30 mg per os, single dose |
Placebo Comparator: Psilocybin-30, Placebo, LSD-100, LSD-200, Psilocybin-15
Cross-over within-subjects design with all treatment conditions, separated by a wash-out phase
|
Drug: LSD
LSD 0.1 mg per os, single dose Drug: LSD LSD 0.2 mg per os, single dose Drug: Psilocybin Psilocybin 15 mg per os, single dose Drug: Psilocybin Psilocybin 30 mg per os, single dose |
Placebo Comparator: Placebo, LSD-100, LSD-200, Psilocybin-15, Psilocybin-30
Cross-over within-subjects design with all treatment conditions, separated by a wash-out phase
|
Drug: LSD
LSD 0.1 mg per os, single dose Drug: LSD LSD 0.2 mg per os, single dose Drug: Psilocybin Psilocybin 15 mg per os, single dose Drug: Psilocybin Psilocybin 30 mg per os, single dose |
- Altered states of consciousness [ Time Frame: 18 Months ]total 5D-ASC score (5-Dimensional Altered States of Consciousness Rating Scale)
- Subjective effects assessed by VAS [ Time Frame: 18 Months ]VAS (Visual analog scale)
- Subjective effects assessed by AMRS scales [ Time Frame: 18 Months ]AMRS scales (Adjective mood Rating scale)
- Psychotomimetic effects [ Time Frame: 18 Months ]ESI (Eppendorf Schizophrenia Inventory)
- Mystical-type experiences assessed by SCQ [ Time Frame: 18 Months ]SCQ (States of consciousness questionnaire)
- Mystical-type experiences assessed by MS scales [ Time Frame: 18 Months ]MS scales (Mysticism scale)
- Effects on emotion processing [ Time Frame: 18 Months ]FERT (Face Emotion Recognition Task)
- Autonomic effects assessed by heart rate [ Time Frame: 18 Months ]Heart rate
- Autonomic effects assessed by blood pressure [ Time Frame: 18 Months ]Blood pressure (diastolic and systolic)
- Autonomic effects assessed by body temperature [ Time Frame: 18 Months ]Body temperature
- Plasma levels of LSD and psilocin [ Time Frame: 18 Months ]assessment of plasma levels of LSD and psilocin

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 25 Years to 65 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Age between 25 and 65 years.
- Understanding of the German language.
- Understanding the procedures and the risks that are associated with the study.
- Participants must be willing to adhere to the protocol and sign the consent form.
- Participants must be willing to refrain from taking illicit psychoactive substances during the study.
- Participants must be willing to drink only alcohol-free liquids and no coffee, black or green tea, or energy drink after midnight of the evening before the study session, as well as during the study day.
- Participants must be willing not to drive a traffic vehicle or to operate machines within 48 h after substance administration.
- Women of childbearing potential must have a negative pregnancy test at the beginning of the study. Pregnancy tests are repeated before each study session.
- Women of childbearing potential must be willing to use double-barrier birth control
- Body mass index 18-29 kg/m2.
Exclusion Criteria:
- Chronic or acute medical condition
- Current or previous major psychiatric disorder
- Psychotic disorder in first-degree relatives
- Illicit substance use (with the exception of cannabis) more than 10 times or any time within the previous two months.
- Pregnant or nursing women.
- Participation in another clinical trial (currently or within the last 30 days)
- Use of medications that may interfere with the effects of the study medications (any psychiatric medications)
- Tobacco smoking (>10 cigarettes/day)
- Consumption of alcoholic drinks (>10/week)
- Bodyweight < 50 kg

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03604744
Switzerland | |
Clinical Pharmacology & Toxicology, University Hospital Basel | |
Basel, Switzerland, 4056 |
Principal Investigator: | Matthias E Liechti, MD, MAS | University Hospital, Basel, Switzerland |
Responsible Party: | University Hospital, Basel, Switzerland |
ClinicalTrials.gov Identifier: | NCT03604744 |
Other Study ID Numbers: |
BASEC 2018-00985 |
First Posted: | July 27, 2018 Key Record Dates |
Last Update Posted: | April 27, 2021 |
Last Verified: | April 2021 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Psilocybin Hallucinogens Physiological Effects of Drugs Psychotropic Drugs |