Adjunctive Effects of Psilocybin and a Formulation of Buprenorphine

Phase I Study of the Safety and Adjunctive Effects of Psilocybin in Adults With Opioid Use Disorder Maintained on a Buprenorphine/Naloxone Formulation

Adjunctive Effects of Psilocybin and a Formulation of Buprenorphine (NCT04161066) is a Phase 1 interventional studying Opioid Use Disorder, sponsored by University of Wisconsin, Madison. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

Primary Aim: In participants with OUD, to characterize adverse events associated with adding two psilocybin doses to a stable buprenorphine-naloxone formulation. Secondary Aim: To evaluate the effect of psilocybin treatment on the effectiveness of a buprenorphine-naloxone maintenance therapy. Secondary Aim: To evaluate the effect of concurrent buprenorphine-naloxone use on the effects of psilocybin therapy. Descriptive Aim: To describe any changes in self-efficacy, quality of life, pain.

What Stage of Research Is This?

Phase 1 trials test a new treatment for the first time in humans, focusing on safety, dosing, and how the body processes the drug. For Opioid Use Disorder, a Phase 1 study typically enrolls a small number of participants — often healthy volunteers or patients who have exhausted standard treatment options. Phase 1 results determine whether a treatment moves into larger Phase 2 efficacy studies.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

With a target enrollment of 10 participants, this is a small study — typical of early-phase research, rare-disease trials, or pilot studies designed to generate preliminary signal before a larger study is launched.

Who May Be Eligible (Plain English)

Who May Qualify: - Aged 21 to 65 years - Able to read, speak, and understand spoken and written English - Diagnosis of moderate or severe opioid use disorder (OUD) - Current opioid misuse, with misuse occurring on at least 10 of the last 30 days (at least 5 of last 30 days if already on buprenorphine/naloxene. See exclusion #1). Misuse will be defined as either: 1. Use of illicit opioids, such as heroin or street fentanyl; or use of a prescription opioid (such as oxycodone, morphine, or hydrocodone) through a route (e.g. nasal, injected) other than FDA approved , and/or 2. Use of a prescription opioid for a purpose (e.g. intoxication, anxiety relief) other than that for which it was prescribed. - Able to achieve stable daily dose of a buprenorphine-naloxone formulation that controls opioid withdrawal symptoms - Persons of childbearing potential must agree to practice an effective means of contraception throughout their participation in the study, beginning at screening and throughout follow-up - Ability and willingness to adhere to study requirements, including attending all study visits, preparatory and follow-up sessions, and evaluations - Healthy kidney function - Able to provide contact information for a local support person. This person must be available during both 24-hour treatment and observation periods, and willing to provide the participant social/emotional support the day after each treatment and as needed during the dosing day and/or overnight observation period. Who Should NOT Join This Trial: - Currently prescribed and has taken buprenorphine or buprenorphine formulation (e.g., Suboxone®) for over four months immediately prior to initial study contact - Currently receiving pharmacotherapy of any duration with methadone ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: * Aged 21 to 65 years * Able to read, speak, and understand spoken and written English * Diagnosis of moderate or severe opioid use disorder (OUD) * Current opioid misuse, with misuse occurring on at least 10 of the last 30 days (at least 5 of last 30 days if already on buprenorphine/naloxene. See exclusion #1). Misuse will be defined as either: 1. Use of illicit opioids, such as heroin or street fentanyl; or use of a prescription opioid (such as oxycodone, morphine, or hydrocodone) through a route (e.g. nasal, injected) other than FDA approved , and/or 2. Use of a prescription opioid for a purpose (e.g. intoxication, anxiety relief) other than that for which it was prescribed. * Able to achieve stable daily dose of a buprenorphine-naloxone formulation that controls opioid withdrawal symptoms * Persons of childbearing potential must agree to practice an effective means of contraception throughout their participation in the study, beginning at screening and throughout follow-up * Ability and willingness to adhere to study requirements, including attending all study visits, preparatory and follow-up sessions, and evaluations * Healthy kidney function * Able to provide contact information for a local support person. This person must be available during both 24-hour treatment and observation periods, and willing to provide the participant social/emotional support the day after each treatment and as needed during the dosing day and/or overnight observation period. Exclusion Criteria: * Currently prescribed and has taken buprenorphine or buprenorphine formulation (e.g., Suboxone®) for over four months immediately prior to initial study contact * Currently receiving pharmacotherapy of any duration with methadone * Current participation in a drug treatment court program or other legal supervision. Individuals who are under legal supervision will be advised that participating in this study could potentially violate terms of probation, parole, or extended supervision. Contact information for the individual's community supervision officer must be collected to confirm whether study participation may impact the potential participant's status on probation or parole * Inadequately treated hypertension * Current acute coronary syndrome or angina * Evidence of ischemic disease, cardiac conduction defects, and/or ventricular arrhythmias on screening ECG * History of heart transplant * Current insulin dependence, due to Type I or Type II diabetes * Urine drug test containing non-prescribed drugs of abuse * Any finding(s), based on the screening process, that the PI feels makes the study unsuitable for the participant

Treatments Being Tested

DRUG

Psilocybin with facilitated counseling

open-label pilot study

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

University of Wisconsin

Madison, Wisconsin, United States

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT04161066), the sponsor (University of Wisconsin, Madison), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT04161066 clinical trial studying?

Who can participate in NCT04161066?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT04161066?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

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Source: ClinicalTrials.gov API v2 record for NCT04161066. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT04161066. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-06-26 · Data from ClinicalTrials.gov.