DDH‑LSD versus LSD: comparing duration, effects, and pharmacokinetics
Pharmacokinetics of Didehydro-LSD (DDH-LSD) Compared With LSD
This study will test whether DDH‑LSD produces LSD‑like psychedelic effects but for a shorter time in healthy adult volunteers.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 24 (estimated) |
| Ages | 18 Years to 65 Years |
| Sex | All |
| Sponsor | University Hospital, Basel, Switzerland Academic / other |
| Locations | 1 site (Basel) |
| Trial ID | NCT07309471 on ClinicalTrials.gov |
What this trial studies
The study has two parts: an open‑label dose‑escalation in healthy volunteers to find a DDH‑LSD dose that produces clear but tolerable psychoactive effects, followed by a randomized, double‑blind, placebo‑controlled cross‑over comparing that DDH‑LSD dose with LSD and placebo. Each participant attends multiple supervised study days with comprehensive measurement of subjective effects, vital signs, and blood sampling for pharmacokinetics. The design allows within‑subject comparison of effect magnitude and time course between DDH‑LSD and LSD. The goal is to generate first‑in‑human data on safety, subjective profile, and duration of DDH‑LSD relative to LSD.
Who should consider this trial
Good fit: Healthy adults aged 25–65 who speak German, have BMI 18–32 kg/m2, no major medical or psychiatric history, and who agree to study rules and abstain from disallowed substances are ideal candidates.
Not a fit: People with significant medical or psychiatric conditions, a history of psychosis or bipolar disorder, uncontrolled blood pressure, pregnant people, or those seeking treatment for psychiatric illness are unlikely to benefit from participation.
Why it matters
Potential benefit: If successful, DDH‑LSD could offer a shorter‑acting psychedelic option that is easier to schedule and monitor in research or therapeutic settings.
How similar studies have performed: LSD and several analogs have been studied before and their pharmacology is well characterized, but DDH‑LSD is a novel compound and this is a first‑in‑human comparison.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: 1. Age between 25 and 65 years old 2. Sufficient understanding of the German language 3. Understanding of procedures and risks associated with the study 4. Willing to adhere to the protocol and signing of the consent form 5. Willing to refrain from the consumption of illicit psychoactive substances during the study 6. Abstaining from xanthine-based liquids from the evenings prior to the study sessions and during the sessions 7. Willing not to operate heavy machinery within 48 h of substance administration 8. Willing to use effective contraceptive measures throughout study participation 9. Body mass index between 18-32 kg/m2 Exclusion Criteria: 1. Chronic or acute medical condition 2. Current or previous major psychiatric disorder 3. Psychotic disorder or bipolar disorder in first-degree relatives 4. Hypertension (SBP\>140/90 mmHg) or hypotension (SBP\<85 mmHg) 5. Use of hallucinogenic substances (not including cannabis) more than 20 times or any time within the previous two months 6. Pregnancy or currently breastfeeding 7. Participation in another clinical trial (currently or within the last 30 days) 8. Use of medication that may interfere with the effects of the study medication 9. Tobacco smoking (\>10 cigarettes/day) 10. Consumption of alcoholic beverages (\>20 drinks/week)
Where this trial is running
Basel
- University Hospital Basel — Basel, Switzerland (Recruiting)
Study contacts
- Study coordinator: Matthias Liechti, Prof. MD
- Email: matthias.liechti@usb.ch
- Phone: +41 61 328 68 68
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.