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Study on the Effects of Lysergide for Patients with Chronic Cluster Headache

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effects of a treatment for chronic cluster headache, a condition characterized by severe headaches that occur in cyclical patterns or clusters. The treatment being tested is a medication called Lysergide D-tartrate, also known as lysergic acid diethylamide (LSD). This medication will be administered as an oral solution, meaning it is taken by mouth in liquid form. The study will also include a comparison with a placebo, which is a substance with no active medication.

The purpose of the study is to evaluate the effectiveness and safety of taking 25 micrograms of LSD every three days over a period of three weeks. Participants in the study will be randomly assigned to receive either the LSD treatment or a placebo. The study aims to determine if the treatment can reduce the frequency of headache attacks in individuals with chronic cluster headache.

Throughout the study, participants will be monitored to assess any changes in their headache patterns and to ensure their safety while taking the medication. The study will help researchers understand if this treatment can provide relief for those suffering from chronic cluster headache and if it is safe for use in this context.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial assessment

    The trial begins with an initial assessment to confirm eligibility. This includes a review of medical history and a diagnosis of chronic cluster headache according to specific criteria.

    Participants must have experienced an average of at least 8 headache attacks per week in the 4 weeks prior to the assessment.

  2. Step 2

    Randomization

    Participants are randomly assigned to receive either the active medication or a placebo. The active medication is Lysergide D-tartrate, administered as an oral solution.

  3. Step 3

    Treatment phase

    During the treatment phase, participants take 25 micrograms of Lysergide every 3 days for a total of 3 weeks.

    The medication is taken orally, and participants are required to maintain a stable regimen of any other headache medications they are using.

  4. Step 4

    Monitoring and evaluation

    Throughout the trial, participants' headache frequency is monitored. The primary goal is to assess the change in weekly attack frequency during the third week of treatment compared to the baseline period.

    Participants are required to attend regular visits for monitoring and evaluation.

  5. Step 5

    End of trial

    The trial concludes with a final assessment to evaluate the overall efficacy and safety of the treatment.

    Participants may be asked to provide feedback on their experience and any changes in their condition.

Who can join the trial?

18 criteria

  • Age between 16 and 75 years at the time of screening.
  • Have a diagnosis of **chronic cluster headache** according to specific medical guidelines (ICHD-3 criteria).
  • During the screening visit, a review of the past 4 weeks shows:
    • An average of at least 8 headache attacks per week.
    • The number of attacks each week is within 40% of the average number of attacks.
    • During the randomization visit, the following conditions are met:
      • An average of at least 8 headache attacks per week.
      • No more than 2 days in a row without any attacks.
      • The number of attacks each week is within 40% of the average number of attacks.
      • The participant has signed a form agreeing to take part in the study. This must be done personally, not by someone else on their behalf.
      • The participant understands and agrees to follow all study procedures and attend all visits.
      • The participant is on a stable treatment plan for preventing cluster headaches and agrees not to change the dose or start new treatments during the study.
      • Women who can become pregnant must have a negative pregnancy test at the start of the study and before treatment begins.
      • All women must agree to either not have sexual intercourse with a male partner or use a reliable method of birth control during the study and for 1 week after the last dose of the study drug. Acceptable birth control methods include:
        • Oral contraceptives (birth control pills).
        • Implantable contraceptives.
        • Injectable contraceptives.
        • A contraceptive patch.
        • Barrier methods like diaphragms with contraceptive jelly, cervical caps with contraceptive jelly, condoms with contraceptive foam, or intrauterine devices (IUDs).
        • A partner who has had a vasectomy.
        • Birth control is not needed if the woman is unable to have children due to surgical procedures (like removal of the uterus or ovaries) or if she has gone through menopause, which is defined as not having a menstrual period for at least 12 months without any medical reason.

Who cannot join the trial?

4 criteria

  • Individuals who do not have chronic cluster headache cannot participate. This is a type of headache that occurs in patterns or clusters.
  • Participants must be within the specified age range. If you are outside this range, you cannot join the study.
  • Both males and females can participate, but if you do not identify as either, you may not be eligible.
  • If you belong to a vulnerable population, you may not be able to participate. This includes groups that might need special protection.
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Investigated drugs

Lysergic Acid Diethylamide (LSD) is being studied for its potential to help people with chronic cluster headaches. In this trial, a small dose of LSD is given every three days over a period of three weeks. The goal is to see if this approach can reduce the frequency or severity of headaches and to ensure that it is safe for patients to use.

What is already known about the treatment

Lysergic Acid Diethylamide (LSD) – This medication is administered orally in the form of a minidose, specifically 25 micrograms every three days over a period of three weeks. Currently, LSD is being studied in clinical trials for its potential use in treating chronic cluster headaches, a condition characterized by severe, recurring headaches. The main therapeutic indication being explored is its ability to alleviate the frequency and intensity of these headaches. At the molecular level, LSD is believed to work by interacting with serotonin receptors in the brain, which may help modulate pain perception and mood. It is classified pharmacologically as a psychedelic compound, known for its effects on perception and cognition.

Investigated diseases

Chronic Cluster Headache – This is a neurological condition characterized by recurrent, severe headaches on one side of the head, often around the eye. These headaches occur in clusters, meaning they happen frequently over a period of time, followed by periods of remission. The pain is typically sharp and intense, and can be accompanied by symptoms such as eye redness, tearing, nasal congestion, or a runny nose on the affected side. Attacks can last from 15 minutes to 3 hours and may occur several times a day. The exact cause is not well understood, but it is believed to involve abnormalities in the hypothalamus, a part of the brain. Chronic cluster headache is distinguished from the episodic form by the lack of significant remission periods.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-520305-39-00Estimated enrolment52 patientsSponsorStichting Radboud universitair medisch centrum

sourced from the EU Clinical Trials Register and site verification

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