General information
  • Disease category Other (BASEC)
  • Study Phase Phase 1 (ICTRP)
  • Recruitment status recruitment completed (BASEC/ICTRP)
  • Trial sites
    Basel
    (BASEC)
  • Contact Matthias Liechti matthias.liechti@usb.ch (BASEC)
  • Data Source(s) BASEC: Import from 06.06.2025 ICTRP: Import from 20.03.2025
  • Last update 06.06.2025 14:11
HumRes57829 | SNCTP000004885 | BASEC2022-00355 | NCT05523401

Acute effects of 2C-B compared to MDMA and psilocybin in healthy subjects

  • Disease category Other (BASEC)
  • Study Phase Phase 1 (ICTRP)
  • Recruitment status recruitment completed (BASEC/ICTRP)
  • Trial sites
    Basel
    (BASEC)
  • Contact Matthias Liechti matthias.liechti@usb.ch (BASEC)
  • Data Source(s) BASEC: Import from 06.06.2025 ICTRP: Import from 20.03.2025
  • Last update 06.06.2025 14:11

Summary description of the study

We investigate the altered states of consciousness induced by 2C-B, MDMA, and psilocybin. As part of the study, you will receive 3 x 2C-B at different dosages (10 mg, 20 mg, and 30 mg), 1 x MDMA (125 mg), 1 x psilocybin (25 mg), and 1 x placebo, with at least 10 days between each. Neither you nor your caregiver will know when you will receive which substance or placebo (“double-blind”). The order of substance administration is randomly determined. Thus, all participants receive all substances, just in a different order. During the study days, we will assess the subjective effect on the psyche using various questionnaires. Additionally, we will repeatedly measure pulse, blood pressure, and body temperature. To investigate the concentration profile of the substances in the blood, blood samples will be taken from you at various time points after substance administration. For this purpose, an intravenous catheter will be placed in your forearm, preferably in the elbow crease, each morning of the study days. The measurements (consisting of blood sampling, blood pressure and pulse measurements, as well as questionnaires) will be conducted in the first half of the day every half hour and in the second half of the day every hour. Between measurements, you will have time to read or listen to music. Throughout the study day, you will be supported by a trained and competent study team member who has extensive experience in handling psychoactive substances.

(BASEC)

Intervention under investigation

As part of the study, you will receive 3x 2C-B (10 mg, 20 mg, 30 mg), 1x MDMA (125 mg), 1x psilocybin (25 mg), and 1x placebo with at least 10 days between each.

(BASEC)

Disease under investigation

Healthy subjects

(BASEC)

Criteria for participation in trial
- Physically and mentally healthy - Aged between 25 and 65 years - BMI between 18 and 29 kg/m2 (BASEC)

Exclusion criteria
- Excessive substance use (including medications, nicotine, and alcohol) - Pregnancy / Breastfeeding - Recent participation in another clinical study (BASEC)

Trial sites

Basel

(BASEC)

Switzerland (ICTRP)

Sponsor

Prof. Dr. med. Matthias E. Liechti

(BASEC)

Contact

Contact Person Switzerland

Matthias Liechti

061 328 68 68

matthias.liechti@usb.ch

Division of Clinical Pharmacology and Toxicology - University Hospital of Basel

(BASEC)

General Information

University Hospital, Basel, Switzerland,

61 328 68 68;61 556 54 22

matthias.liechti@usb.ch

(ICTRP)

General Information

University Hospital, Basel, Switzerland

(ICTRP)

Scientific Information

University Hospital, Basel, Switzerland,

61 328 68 68;61 556 54 22

matthias.liechti@usb.ch

(ICTRP)

Name of the authorising ethics committee (for multicentre studies, only the lead committee)

Ethics Committee northwest/central Switzerland EKNZ

(BASEC)

Date of authorisation

21.04.2022

(BASEC)


ICTRP Trial ID
NCT05523401 (ICTRP)

Official title (approved by ethics committee)
Acute effects of 10, 20 and 30 mg 2C-B compared with 125 mg MDMA and 25 mg psilocybin in healthy subjects (BASEC)

Academic title
Acute Effects of 2C-B Compared With MDMA and Psilocybin in Healthy Subjects (ICTRP)

Public title
Acute Effects of 2C-B Compared With MDMA and Psilocybin in Healthy Subjects (ICTRP)

Disease under investigation
Healthy (ICTRP)

Intervention under investigation
Drug: 4-bromo-2,5-dimethoxyphenethylamine (10 mg)Drug: 4-bromo-2,5-dimethoxyphenethylamine (20 mg)Drug: 4-bromo-2,5-dimethoxyphenethylamine (30 mg)Drug: 3,4-methylenedioxymethamphetamineDrug: PsilocybinOther: Placebo (ICTRP)

Type of trial
Interventional (ICTRP)

Trial design
Allocation: Randomized. Intervention model: Crossover Assignment. Primary purpose: Basic Science. Masking: Triple (Participant, Care Provider, Investigator). (ICTRP)

Inclusion/Exclusion criteria
Inclusion Criteria:

- Age between 25 and 65 years.

- Sufficient 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 between 18-29kg/m2

Exclusion Criteria:

- Chronic or acute medical condition, including a history of seizures.

- Current or previous major psychiatric disorder (e.g. psychotic disorders, mania /
hypomania, anxiety disorders).

- Psychotic or bipolar disorder in first-degree relatives, not including psychotic
disorders secondary to an apparent medical reason, e.g. brain injury, dementia, or
lesions of the brain.

- Hypertension (SBP>140/90 mmHg) or hypotension (SBP<85 mmHg)

- Ilicit substance use (with the exception of cannabis) more than 20 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 and any medication with known to interact with the study
substances).

- Tobacco smoking (>10 cigarettes/day).

- Consumption of alcoholic drinks (>20 drinks / week).

- Body weigt < 45 kg. (ICTRP)

not available

Primary and secondary end points
Acute subjective effects I (ICTRP)

Acute subjective effects II;Acute subjective effects III;Autonomic effects I;Autonomic effects II;Autonomic effects III;Plasma levels of 2C-B, MDMA, and psilocybin;Plasma levels of oxytocin;Plasma levels of Brain-derived neurotropic factor (BDNF);Adverse effects;Urine Recovery;States of Consciousness Questionnaire;Spiritual Realms Questionnaire;Psychological Insight Questionnaire;NEO-Five-Factor-Inventory (NEO-FFI);Freiburger Personality Inventory (FPI-R);Saarbr�cker Personality Questionnaire (SPF);HEXACO personality inventory;Defense Style Questionnaire (DSQ-40) (ICTRP)

Registration date
not available

Incorporation of the first participant
not available

Secondary sponsors
not available

Additional contacts
Matthias E Liechti, MD;Matthias E Liechti, MD;Denis Arikci, MD, matthias.liechti@usb.ch; denis.arikci@usb.ch, 61 328 68 68;61 556 54 22, University Hospital, Basel, Switzerland, (ICTRP)

Secondary trial IDs
BASEC 2022-00355 (ICTRP)

Results-Individual Participant Data (IPD)
not available

Further information on the trial
https://clinicaltrials.gov/ct2/show/NCT05523401 (ICTRP)

Results of the trial

Results summary

not available

Link to the results in the primary register

not available