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Recruiting NCT07309471

Pharmacokinetics of Didehydro-LSD (DDH-LSD) Compared With LSD

No phase Interventional LSD Reaction

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: DDH-LSD, LSD, Placebo.
Who it may be relevant to
Registry conditions: LSD Reaction. Basic parameters: 18 years — 65 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
Switzerland
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

Unsure about the terms? Read our patient guide →

Overview

This study investigates DDH-LSD, a novel LSD-like compound expected to have a shorter duration of action than LSD. In healthy volunteers, pharmacokinetics, safety, and subjective effects, will be assessed and compare with LSD in a controlled cross-over study.

Detailed description

LSD is a classical serotonergic psychedelic that produces profound alterations in perception and consciousness, primarily through 5-HT2A receptor agonism. Numerous LSD analogs have emerged in recent years, some functioning as prodrugs of LSD, while others show distinct pharmacological characteristics. DDH-LSD is a newly synthesized lysergamide with LSD-like receptor activity but faster metabolism in vitro, suggesting a shorter elimination half-life and potentially briefer psychedelic effects.

This study consists of two parts.

Substudy 1 is an open-label dose-escalation trial in which healthy participants receive increasing doses of DDH-LSD to identify a dose that produces clear but tolerable psychoactive effects.

Substudy 2 is a randomized, double-blind, placebo-controlled cross-over study comparing the selected DDH-LSD dose with LSD and placebo. Each participant completes multiple supervised study days with comprehensive assessment of subjective effects, physiological responses, and pharmacokinetics.

The goal is to provide first-in-human data on DDH-LSD, characterize its effect profile, and evaluate how its duration of action compares with LSD.

Interventions

  • Drug DDH-LSD
    Single oral dose of DDH-LSD at the dose determined in Substudy 1. Participants are monitored for 13 hours for pharmacokinetics, subjective effects, autonomic responses, and safety parameters.
  • Drug LSD
    Single oral dose of 0.1 mg LSD. Participants are monitored for 13 hours for pharmacokinetics, subjective effects, autonomic responses, and safety parameters.
  • Drug Placebo
    Single oral administration of placebo. Participants are monitored for 13 hours under identical conditions to control for expectancy and procedural effects.

Primary outcome measures

  • Determine effective DDH-LSD dose [Time frame: During each 13-hour study session.]
  • Compare duration of action and elimination half-life [Time frame: During each 13-hour study session.]
Secondary outcome measures (11)
  • Pharmacokinetics of DDH-LSD [Time frame: During each 13-hour study session]
  • Subjective effects: Visual Analog Scales (VAS) [Time frame: During each 13-hour study session]
  • Subjective effects: Adjective Mood Rating Scale (AMRS / EWL60S) [Time frame: Following each 13-hour study session]
  • Subjective effects: 5-Dimensions of Altered States of Consciousness (5D-ASC) [Time frame: Following each 13-hour study session]
  • Subjective effects: Spiritual Realm Questionnaire (SRQ) [Time frame: Following each 13-hour study session]
  • Subjective effects: States of Consciousness Questionnaire (SCQ / MEQ) [Time frame: Following each 13-hour study session]
  • Effect on heart rate (HR) [Time frame: During each 13-hour study session]
  • Effect on blood pressure [Time frame: During each 13-hour study session]
  • Effect on body temperature [Time frame: During each 13-hour study session]
  • Subjective effects: Scale of Positive and Negative Experience (SPANE) [Time frame: Before each 13-hour study session]
  • Subjective effects: Psychological Insight Questionnaire (PIQ) [Time frame: Following each 13-hour study session]

Eligibility criteria

Inclusion criteria

  • Age between 25 and 65 years old
  • Sufficient understanding of the German language
  • Understanding of procedures and risks associated with the study
  • Willing to adhere to the protocol and signing of the consent form
  • Willing to refrain from the consumption of illicit psychoactive substances during the study
  • Abstaining from xanthine-based liquids from the evenings prior to the study sessions and during the sessions
  • Willing not to operate heavy machinery within 48 h of substance administration
  • Willing to use effective contraceptive measures throughout study participation
  • Body mass index between 18-32 kg/m2

Exclusion criteria

  • Chronic or acute medical condition
  • Current or previous major psychiatric disorder
  • Psychotic disorder or bipolar disorder in first-degree relatives
  • Hypertension (SBP>140/90 mmHg) or hypotension (SBP<85 mmHg)
  • Use of hallucinogenic substances (not including cannabis) more than 20 times or any time within the previous two months
  • Pregnancy or currently breastfeeding
  • Participation in another clinical trial (currently or within the last 30 days)
  • Use of medication that may interfere with the effects of the study medication
  • Tobacco smoking (>10 cigarettes/day)
  • Consumption of alcoholic beverages (>20 drinks/week)

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation
Randomized
Model
Crossover
Masking
Quadruple blind
Primary purpose
Other

Study locations

Switzerland · 1 center
  • University Hospital Basel — Basel

Identifiers

NCT: NCT07309471 · 2023-01737;am23Liechti3

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗