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Study on Psilocybin's Effect on Pain in Fibromyalgia Patients

Fast replyInvestigationalNo placebo
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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 psilocybin on individuals with fibromyalgia, a condition characterized by widespread pain and tenderness in the body. The study aims to explore how low doses of psilocybin, a compound found in certain mushrooms, can influence pain perception in people with fibromyalgia. Participants will receive either psilocybin or a placebo in the form of capsules.

The purpose of the study is to assess whether psilocybin can help reduce pain in fibromyalgia patients and to examine its effects on mood, thinking, and memory. The study will also look at how psilocybin might affect certain proteins in the body, such as BDNF (Brain-Derived Neurotrophic Factor), which is involved in nerve growth and function. Additionally, researchers will investigate if psilocybin can influence levels of inflammation-related substances in the blood.

Participants will take part in several sessions where they will receive either psilocybin or a placebo. During these sessions, various assessments will be conducted to evaluate changes in pain, mood, and other factors. The study will also explore whether suggestions given under hypnosis can alter the effects of psilocybin on pain. The trial is expected to continue until mid-2026, with recruitment starting in mid-2024.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial assessment

    Participants undergo an initial assessment to confirm eligibility. This includes verifying age, weight, language proficiency, and understanding of the study procedures.

    Participants must meet specific criteria, such as having a fibromyalgia diagnosis and a minimum pain score of 5 out of 10.

  2. Step 2

    Preparation for study sessions

    Participants agree to avoid alcohol, coffee, tea, and energy drinks after midnight before study sessions.

    Participants must refrain from driving or operating machinery for 24 hours after taking the study substance.

  3. Step 3

    Medication administration

    Participants receive either a 5 mg or 10 mg dose of psilocybin in capsule form, or a placebo, taken orally.

    The effects of psilocybin on pain perception and other factors are monitored.

  4. Step 4

    Monitoring and evaluation

    Participants' pain levels and other responses are assessed using subjective measures and specific tests.

    The study also evaluates mood, cognition, personality, memory, and any psychedelic experiences.

  5. Step 5

    Biomarker analysis

    Blood samples are taken to measure levels of certain biomarkers, such as inflammatory proteins, to assess the biological impact of psilocybin.

  6. Step 6

    Follow-up

    Participants are monitored for any changes in pain perception and other study-related outcomes over time.

    The study aims to complete by June 18, 2026.

Who can join the trial?

11 criteria

  • Age between 18 and 65 years
  • Willingness to drink only alcohol-free liquids and no coffee, black or green tea, or energy drinks after midnight of the evening before the study session, as well as during the study days
  • Willingness not to drive a traffic vehicle or to operate machines within 24 hours after substance administration
  • Normal weight, with a body mass index (BMI) between 18 and 30 kg/m2. BMI is a measure of body fat based on height and weight.
  • Fulfilment of the American College of Rheumatology criteria for FM diagnosis. FM stands for fibromyalgia, a condition characterized by widespread pain.
  • A minimum NRS pain score of 5 out of 10. NRS stands for Numerical Rating Scale, a way to measure pain intensity.
  • Proficient knowledge of the Dutch or English language
  • Written Informed Consent. This means agreeing to participate in the study after understanding all the details and risks.
  • Understanding the procedures and the risks associated with the study
  • No regular use of psychotropic medication such as opiates, antidepressants, muscle relaxants, anticonvulsants, sleep aids, benzodiazepines. These are medications that affect the mind. Non-pharmacological regimens will be allowed along with one rescue therapy such as acetaminophen up to 4,000 mg/day, ibuprofen up to 1,200 mg/day, naproxen up to 660 mg/day, or ketoprofen up to 75 mg/day. Use of paracetamol (PCM) and non-steroidal anti-inflammatory drugs (NSAIDS) will be allowed and monitored.
  • Willingness to refrain from taking psychoactive substances during the study. These are substances that can change mood or behavior.

Who cannot join the trial?

4 criteria

  • Individuals who are not within the specified age range for the study.
  • Individuals who do not have a diagnosis of Fibromyalgia, which is a condition characterized by widespread pain and tenderness in the body.
  • Individuals who are part of a vulnerable population, meaning groups that may need special protection or care.
  • Individuals who do not meet other specific health criteria set by the study, which are not detailed here.
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Investigated drugs

Psilocybin is a substance being studied for its potential to help reduce pain in patients with fibromyalgia. In this trial, researchers are looking at how small doses of psilocybin might change how patients feel pain and whether it affects certain chemicals in the brain related to pain perception.

What is already known about the treatment

Psilocybin – Psilocybin is administered orally, typically in capsule form. It is currently being studied in clinical trials for its potential effects on pain management in fibromyalgia patients. The main therapeutic indication being explored is its ability to alter pain perception. At the molecular level, psilocybin works by interacting with serotonin receptors in the brain, which may influence mood and perception. It is classified pharmacologically as a psychedelic compound.

Investigated diseases

Fibromyalgia – Fibromyalgia is a chronic condition characterized by widespread musculoskeletal pain, fatigue, and tenderness in localized areas. It often involves symptoms such as sleep disturbances, memory issues, and mood swings. The exact cause is unknown, but it is believed to involve a combination of genetic, environmental, and psychological factors. The pain associated with fibromyalgia is thought to result from abnormal pain processing in the brain. Symptoms can vary in intensity and may be triggered by stress, physical activity, or changes in weather. It is more common in women and can significantly impact daily functioning and quality of life.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-516890-63-00Estimated enrolment35 patientsSponsorUniversiteit Maastricht

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