Psilocybin Therapy for Chronic Low Back Pain (POP)

April 23, 2026 updated by: Joshua Woolley, MD, PhD

A Double-blind, Randomized Trial Examining the Preliminary Efficacy of Psilocybin Therapy for People With Chronic Low Back Pain

This study evaluates whether psilocybin therapy helps patients cope with chronic low back pain more effectively. Patients may be recruited at Stanford and University of California San Francisco (UCSF), study procedures will occur at UCSF. Each participant will receive a dose of psilocybin with possibly one or more other drugs. Participants will undergo two preparation sessions, a dosing session, three integration sessions to discuss their psilocybin experience, and several follow up sessions.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Chronic pain is associated with higher levels of pain-related distress, depression, emotional dysfunction, helplessness, hopelessness, and suicidality. Psilocybin is a psychoactive drug that may be well-suited to easing the psychological and emotional symptoms of distress associated with chronic pain. Previous studies testing psilocybin therapy have shown improvements on multiple behavioral and psychiatric outcomes, but it is unknown whether psilocybin therapy similarly enables patients to cope with chronic pain more effectively. The investigators will determine whether psilocybin therapy improves patients' ability to cope with chronic low back pain. If psilocybin therapy is an effective treatment in this population, its use could be incorporated into interventions for chronic low back pain and other psychological conditions.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • California
      • San Francisco, California, United States, 94107
        • University of California San Francisco

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

25 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age 25 to 70 years old
  • Comfortable speaking and writing in English
  • Diagnosed with chronic low back pain
  • Able to attend all in-person visits at UCSF as well as virtual visits
  • Has tried at least two previous medications/ procedures and physical therapy trials for low back pain

Exclusion Criteria:

  • Chronic low back pain that is attributed to malignancy, subacute or acute fracture or infection
  • Low back pain with radiation below the knee
  • Low back pain with neurologic signs present
  • Regular use of medications that may have problematic interactions with psilocybin, including but not limited to dopamine agonists, MAO inhibitors, antipsychotics, and stimulants
  • A health condition that makes study unsafe or unfeasible, determined by study physicians

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Psilocybin in combination with Zolpidem and Modafinil
Single dose of Psilocybin (1mg-30mg) in combination with zolpidem and modafinil
Drug: Psilocybin therapy with Zolpidem and Modafinil
1-30 mg (oral administration), Modafinil (oral administration), and Zolpidem (oral administration)
Other Names:
  • 4-phosphoryloxy- N,N-dimethyltryptamine
Experimental: Psilocybin in combination with Zolpidem
Single dose of Psilocybin (1mg-30mg) in combination with zolpidem
Drug: Psilocybin therapy with Zolpidem
1-30 mg (oral administration), Zolpidem (oral administration), and placebo (oral administration)
Other Names:
  • 4-phosphoryloxy- N,N-dimethyltryptamine
Experimental: Psilocybin in combination with Modafinil
Single dose of Psilocybin (1mg-30mg) in combination with modafinil
Drug: Psilocybin therapy with Modafinil
1-30 mg (oral administration), Modafinil (oral administration), and placebo (oral administration)
Other Names:
  • 4-phosphoryloxy- N,N-dimethyltryptamine
Experimental: Psilocybin in combination with Placebo
Single dose of Psilocybin (1mg-30mg) in combination with placebo
Drug: Psilocybin therapy with Placebo
1-30 mg (oral administration), and placebo (oral administration)
Other Names:
  • 4-phosphoryloxy- N,N-dimethyltryptamine

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in pain interference
Time Frame: Baseline, 1-month after psilocybin session
The Brief Pain Inventory-Interference subscale (BPI) will be used to assess how pain interferes with a variety of daily activities (e.g., walking, lifting, mood, sleep, relationships). Seven items are rated on a scale from 0 (does not interfere) to 10 (completely interferes) for a total possible score ranging from 0 to 70. Higher scores represent greater interference from pain.
Baseline, 1-month after psilocybin session

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in pain interference
Time Frame: Baseline, 1-week, and 3-months
The Brief Pain Inventory-Interference subscale (BPI) will be used to assess how pain interferes with a variety of daily activities (e.g., walking, lifting, mood, sleep, relationships). Seven items are rated on a scale from 0 (does not interfere) to 10 (completely interferes) for a total possible score ranging from 0 to 70. Higher scores represent greater interference from pain.
Baseline, 1-week, and 3-months
Change in average pain intensity
Time Frame: Baseline, 1-week, 1-month, and 3-months after psilocybin session
The Brief Pain Inventory with the Michigan Body Map will be used to assess pain location and worst, least, average, and present pain on a numerical rating scale from 0 (no pain) to 10 (pain as bad as you can imagine) over the past 24 hours, where higher scores represent greater pain intensity.
Baseline, 1-week, 1-month, and 3-months after psilocybin session
Change in clinical depressive symptom severity
Time Frame: Baseline, 1-week, 1-month, and 3-months after psilocybin session
The 17-item clinician administered Hamilton Rating Scale for Depression will be used to assess changes in the severity of depressive symptoms. Each item is scored by a clinician on a 3- or 5-point scale from 0 (Not present) to 4 (severe) and summed for a total score between 0 and 52. A higher total score represents greater depressive symptom severity.
Baseline, 1-week, 1-month, and 3-months after psilocybin session
Change in depressive symptom severity
Time Frame: Baseline, pre-dosing session, 5-days, 11-days, and 77-days after psilocybin session
The 7-item PROMIS-Depression self-report scale will be used as an additional indicator for changes in depression symptom severity. Items are endorsed on a 5-point scale ranging from 1 (Never) to 5 (Always). A higher total score represents greater depressive symptom severity.
Baseline, pre-dosing session, 5-days, 11-days, and 77-days after psilocybin session

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Joshua Woolley, MD, PhD

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Joshua Woolley, University of California, San Francisco

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 1, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 22, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 22, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 28, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 29, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 23, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 20-21441

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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