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Psilocybin‑Assisted Psychotherapy for Adults with Sex Addiction: A Pilot Study

Verified siteInvestigationalNo placebo
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What is this trial about?

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

The condition being studied is Sex addiction, a pattern of sexual thoughts or behaviors that feel out of control and cause distress. The treatment under investigation combines a talk‑based therapy called psychotherapy with an oral capsule containing psilocybin, a naturally occurring substance that can produce temporary changes in perception and mood. The medication is given as a pill, and participants also receive several guided therapy sessions to help them process their experiences.

The study’s purpose is to determine whether a larger trial can be carried out successfully. Participants are assigned by chance to one of two groups: one group receives a higher amount of the capsule (25 mg) and the other receives a much lower amount (3 mg), with both groups attending the same number of therapy sessions and follow‑up visits. The schedule includes a series of visits where the capsule is taken, the therapy sessions are held, and safety checks are performed, followed by later appointments to see if participants remain in the study until the end.

The research process

The trial runs in 7 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Baseline Assessment

    You will complete a set of questionnaires that measure self‑efficacy, overall severity of symptoms, self‑compassion, and spirituality. Your heart rate and blood pressure will also be recorded. This assessment establishes a starting point for the study.

  2. Step 2

    Randomization

    After the baseline assessment, you will be assigned by chance to one of two groups. One group receives the experimental dose of psilocybin (25 mg) and the other receives a low dose (3 mg) used as a comparator. The assignment is concealed so that neither you nor the study staff know which dose you will receive until the medication session.

  3. Step 3

    Preparation Psychotherapy Session

    Before taking any medication, you will meet with a therapist for a preparation session. The therapist explains what to expect during the medication session, discusses your goals, and helps you feel safe and ready.

  4. Step 4

    Medication Administration Session

    You will take one oral capsule containing the assigned dose of psilocybin (either 25 mg or 3 mg). The capsule is swallowed with water under the supervision of study staff. Your heart rate, blood pressure, and any immediate effects are monitored throughout the session. The observation period lasts several hours to ensure safety.

  5. Step 5

    Integration Psychotherapy Session

    After the medication session, you will have an integration session with the therapist. During this meeting you discuss your experiences, reflect on insights, and plan how to apply what you learned to everyday life.

  6. Step 6

    Follow‑up Assessments

    At scheduled times after the integration session, you will repeat the same questionnaires used at baseline. These follow‑up assessments measure any changes in self‑efficacy, symptom severity, self‑compassion, and spirituality. Heart rate and blood pressure may also be checked again during any additional medication sessions if required.

  7. Step 7

    Final Study Visit

    When all required sessions and assessments are completed, you will attend a final visit. This visit confirms that you have finished every part of the protocol, and any remaining study paperwork is completed.

Who can join the trial?

11 criteria

  • Be 18 years old or older, regardless of gender.
  • Have a negative result on a urine toxicology screening (a test that checks the urine for drugs).
  • If you take any psychotropic medication (drugs that affect the mind) other than nicotine replacement therapy, the dose must be stable or you must have been using it for more than one month.
  • Have a current diagnosis of sex addiction confirmed using the Carnes diagnostic criteria (a set of guidelines doctors use to identify this condition).
  • Be able to complete the study’s self‑assessment questionnaires (forms that ask about your symptoms and feelings).
  • Agree to have a blood test and an electrocardiogram (ECG) (a test that records the heart’s electrical activity).
  • Be able to read and understand French, both in writing and spoken.
  • Sign an informed consent form before any study procedures begin (a document that explains the study and confirms you agree to take part).
  • Be covered by the French social security system (the national health insurance program).
  • If you are a woman who could become pregnant, have a negative pregnancy test and use a highly effective form of birth control, as defined by the latest clinical trial guidelines.
  • If you are a man who could father a child, use an effective form of birth control, as defined by the latest clinical trial guidelines.

Who cannot join the trial?

26 criteria

  • Severe trouble thinking or remembering things (score less than 26 on a simple memory test called the Mini‑Mental State Examination).
  • Being judged at high risk of suicide right now using a standard questionnaire (the MINI 5.0 suicide risk module).
  • Having had problems with hallucinogen drugs (drugs that cause vivid hallucinations) now or using them within the last year.
  • Having an alcohol problem now and having had symptoms when stopping alcohol before (like shaking, sweating, anxiety).
  • Being very underweight (body mass index < 16.5) or obese (body mass index > 30). BMI is a measure of weight relative to height.
  • Having epilepsy, a condition that causes seizures.
  • Having severe liver disease or damage, shown by blood tests that are far above normal or symptoms such as fatigue, nausea, pain in the right upper abdomen, fever, rash, or a high number of eosinophils (a type of white blood cell).
  • Having reduced kidney function (estimated glomerular filtration rate < 90 mL per minute). eGFR measures how well the kidneys filter blood.
  • Having coronary heart disease (narrowing or blockage of the heart’s blood vessels).
  • Having a past irregular heartbeat (arrhythmia).
  • Having heart failure (the heart cannot pump blood well).
  • Being allergic to psilocybin (the active drug) or any of the inactive ingredients in the study medication.
  • Having high blood pressure that is not under control with medication.
  • Having had a stroke in the past.
  • Having severe asthma (trouble breathing that is hard to control).
  • Having an overactive thyroid gland (hyperthyroidism).
  • Having narrow‑angle glaucoma, an eye condition that can cause sudden vision loss.
  • Having prostate enlargement or blockage in the bladder neck that causes symptoms.
  • Having important heart rhythm problems shown on an ECG, such as a prolonged QT interval (≥450 ms for men, ≥470 ms for women), a history of a dangerous rhythm called torsades de pointes, serious ventricular arrhythmia, a high‑grade heart block without a pacemaker, or any other serious ECG finding.
  • Currently taking medicines that block certain enzymes (UGT1A9, UGT1A10, ALDH, ADH) that affect how the study drug is processed.
  • Being pregnant or breastfeeding.
  • Being under legal guardianship or court protection.
  • Being enrolled in another clinical trial that uses therapy or medication that could affect the study.
  • Having a current or past diagnosis of psychotic disorder (loss of contact with reality) or bipolar disorder (extreme mood swings).
  • Having any other mental health condition that is not stable.
  • Having a close family member (parent, sibling, or child) with a psychotic disorder or type 1 bipolar disorder.
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Investigated drugs

  • Psilocybin

    is a naturally occurring compound that produces psychedelic effects. In this trial participants take it as a capsule taken by mouth. The medication is being tested to see if, when combined with therapy, it can help reduce the urge and behaviors associated with sex addiction.

  • Psilocybin

    is also used as a low‑dose comparison in the study. The same substance is given in a smaller amount, allowing researchers to compare the effects of a higher dose with a lower dose and determine whether the dose makes a difference in the treatment outcome.

  • Psilocybin‑assisted psychotherapy

    is a therapeutic approach where participants receive the psilocybin medication and then engage in guided counseling sessions with a trained therapist. The therapy aims to help participants explore their thoughts, emotions, and behaviors in a supportive setting, with the goal of reducing addictive patterns and improving overall well‑being.

What is already known about the treatment

PSILOCYBINE - Psilocybin is taken as an oral capsule that you swallow; it is still experimental and not yet an approved medicine, though many studies are examining its effects. The main condition being tested is compulsive sexual behavior, using psilocybin together with psychotherapy. It works by briefly activating serotonin receptors in the brain, which can shift mood, perception, and thought patterns. Psilocybin belongs to the psychedelic tryptamine class of substances.

Investigated diseases

Sex addiction - Sex addiction is a pattern of compulsive sexual thoughts and behaviors that the person finds difficult to control. It often leads to increasing time spent on sexual activities, neglect of responsibilities, and distress. Over time, the behavior may become more frequent and intense, interfering with relationships, work, and daily life. Individuals may experience cravings and attempts to cut back that are unsuccessful. The condition can persist or worsen if underlying triggers are not addressed.
Trial detailsLast updated 2 Nov 2026
Age18+ yearsPhasePhase IITrial ID2026-527083-32-00Protocol codeRC26_0047 ATANAOSEstimated enrolment30 patientsSponsorCentre Hospitalier Universitaire De Nantes

sourced from the EU Clinical Trials Register and site verification

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