What happens in a psilocybin therapy session: screening, preparation, the dosing day and integration

“Psilocybin therapy” can sound like taking mushrooms in a therapist’s office. The published research describes something much more structured. In the trials that made headlines, the drug session sits inside weeks of screening, preparation and follow-up, and a team stays with the participant for the whole day (Johnson et al., 2008; Goodwin et al., 2023).

This page walks through each stage as named trial protocols and guidelines describe it: the Johns Hopkins safety guidelines and depression trial, the COMP360 trials sponsored by COMPASS Pathways, Imperial College London’s comparison with an antidepressant, a 2025 expert consensus statement, and Oregon’s licensed service-centre model as a point of comparison. It then shows how this maps to the legal routes in Canada. For how the routes themselves work, see our guide to psilocybin-assisted therapy in Canada.

What is psilocybin-assisted therapy?

It is psilocybin given alongside structured psychological support. A 2025 consensus statement from a task group of the US National Network of Depression Centers (NNDC) notes that protocols differ, but that in most efficacy studies the support is given before and after the drug session, a model historically called “psychedelic therapy”. That contrasts with MDMA trials, where support is given during the session (Hosein et al., 2025).

The training paper for therapists in the COMP360 program puts it simply: “Psilocybin therapy has three phases: preparation, psilocybin session, and integration.” Safety underpins all three (Tai et al., 2021). Before any of those comes screening.

Two facts frame everything below. First, no psilocybin product is approved in Canada or anywhere else, according to Health Canada (Health Canada). Second, the consensus authors say the separate contributions of the drug and the psychotherapy are “not yet separable” on current evidence (Hosein et al., 2025). Nobody yet knows which parts of the package matter most.

How do trials decide who qualifies for psychedelic therapy?

Screening is strict, and most people who apply do not take part. In the Johns Hopkins depression trial, 870 people were screened by phone or online survey, 70 went on to in-person medical and psychological screening, 43 of those were disqualified, and 27 were enrolled (Davis et al., 2021).

The Johns Hopkins safety guidelines, written in 2008 from that centre’s early studies, list a detailed medical history, physical exam, 12-lead ECG, blood chemistry, hematology and urinalysis. People were excluded if their resting blood pressure was above 140/90 on average over four readings on at least two days. On the psychiatric side, a current or past psychotic disorder or bipolar I or II disorder excluded people, and so did having a first- or second-degree relative with one (Johnson et al., 2008).

Later trials kept the core of those rules and added their own. The table compares three protocols. It summarizes the registered or published criteria; each trial has more.

The consensus statement points out what this means for real-world care. Research patients are rigorously screened, while in ordinary clinics histories are often partial or unclear, so trial results may not carry over to everyone (Hosein et al., 2025). How psilocybin interacts with medications such as antidepressants is covered in our article on magic mushrooms and antidepressants.

What happens during preparation?

Preparation is several meetings with the people who will be present on the dosing day. The Johns Hopkins guidelines describe at least eight contact hours over at least four meetings, usually across a month, with one meeting held in the session room so it is familiar (Johnson et al., 2008). The later Johns Hopkins depression trial had eight hours of preparation with two session facilitators (Davis et al., 2021).

In a published COMP360 study, preparation took three sessions with a therapist trained by the sponsor. The therapist built trust, explained the trial, gave information about what to expect and helped the participant prepare. The last session was the day before dosing and included safety checks to confirm the person was still eligible (Goodwin et al., 2023).

• Building trust. The guidelines describe rapport with the session staff as one of the main ways to reduce fear during the session (Johnson et al., 2008).
• Consent and expectations. Participants hear, in plain language, the range of possible effects, including anxiety, fear or paranoia, and physical effects such as nausea (Johnson et al., 2008). The consensus authors suggest consent may need a more thorough educational phase than usual, because people under the drug may be more open to suggestion (Hosein et al., 2025).
• Practising an approach. The COMP360 training describes “self-directed enquiry”: noticing thoughts, feelings and body sensations as they arise, practised on topics the participant chooses (Tai et al., 2021).
• Logistics. Timing, restrictions set by the protocol, and who will accompany the person home are agreed in advance (Johnson et al., 2008).

The idea that mindset and surroundings shape the experience has a long history, traced in our article on set and setting.

What happens on the dosing day of a psilocybin therapy session?

The session room is usually furnished like a living room rather than a clinic. In the Johns Hopkins depression trial, participants lay on a couch, wore eyeshades and headphones playing a set music playlist, and were encouraged to focus inward. Both facilitators stayed in the room all day, apart from short breaks taken one at a time (Davis et al., 2021).

In the COMP360 study, each participant was accompanied by the lead therapist from their preparation for the six- to eight-hour session. The therapist’s role was to keep the person physically and psychologically safe and to encourage attention to the experience “while avoiding active guidance”. An assisting therapist was nearby, a study psychiatrist was on site, and blood pressure was monitored continuously with a finger cuff. Up to six participants could be dosed at once, each in a separate room (Goodwin et al., 2023).

• Two trained people. The Johns Hopkins guidelines recommend at least two monitors so the participant is never alone (Johnson et al., 2008). The COMP360 training paper says the FDA requires two trained therapists for every session in US trials, with at least a master’s level of education (Tai et al., 2021).
• Medical back-up. A physician should be available, with medicine for a sharp rise in blood pressure on hand (Johnson et al., 2008).
• Reassurance first. If a participant becomes anxious, the first response the guidelines describe is calm personal support. In 54 volunteers given high doses at Johns Hopkins up to 2008, reassurance alone handled every case of acute distress (Johnson et al., 2008).
• Going home. Participants leave only after the effects have worn off, in the care of a friend or family member (or stay overnight), and are told not to drive for the rest of the day (Johnson et al., 2008; Goodwin et al., 2023).

What happens after the session?

Follow-up begins quickly. The Johns Hopkins guidelines describe a meeting, typically the next day, to check psychological stability and let the person talk through the experience, with more meetings if needed (Johnson et al., 2008). In the COMP360 study, integration sessions with the lead therapist took place on day 2 and at week 1, and participants were followed for three weeks (Goodwin et al., 2023).

Integration means reflecting on the session and relating it to one’s own life. The COMP360 training describes it as a process that unfolds over time as the person makes changes (Tai et al., 2021). Trials also keep measuring. The COMP005 phase 3 trial, for example, lasts about 62 weeks in all, including a screening period of three to ten weeks, a six-week placebo-controlled part, then re-treatment and open-label parts (ClinicalTrials.gov NCT05624268).

What risks do the protocols monitor for?

Monitoring exists because things do go wrong. In the largest published COMP360 trial, 233 people with treatment-resistant depression were randomized to one of three dose levels with psychological support. Adverse events occurred in 179 of them (77%), including headache, nausea and dizziness, and suicidal ideation or behaviour or self-injury occurred in all dose groups (Goodwin et al., 2022). The consensus authors describe this as a possible signal that needs careful study, and they flag expectations and disappointment after an underwhelming session as a concern (Hosein et al., 2025).

In the smaller Johns Hopkins trial there were no serious adverse events. One session saw a temporary blood-pressure rise past the protocol’s threshold that settled without treatment, and headache was reported during a third of sessions (Davis et al., 2021). Results on effectiveness are mixed: the Imperial trial found no significant difference from an established antidepressant on its main measure (Carhart-Harris et al., 2021). For the trial evidence, see our look at psilocybin depression trials.

The consensus statement also names risks in the relationship itself. People under the drug may be more suggestible, boundary violations can happen, and the authors suggest third-party monitoring or video recording could help protect patients. They add that standardized evaluation of practitioner competence “is nonexistent” (Hosein et al., 2025).

How does Oregon’s licensed service-centre model compare?

Oregon offers a useful contrast because it is not a medical treatment program. A client must be 21 or older, needs no prescription or referral, and does not have to live in Oregon. Psilocybin services there mean preparation, administration and integration sessions. Psilocybin may only be consumed at a licensed service centre during an administration session with a licensed facilitator present (Oregon Health Authority, services; Oregon Health Authority, access).

Oregon has its own screening. During preparation, clients complete a standard client information form. The state says a client may be found ineligible if they are “experiencing ideation of harm to self or others, have taken Lithium within 30 days, or have been diagnosed with active psychosis at any time”. Every client completes a safety and support plan and a transportation plan, and facilitators follow up within 72 hours (Oregon Health Authority, access). Those rules are lighter than trial exclusions, and psilocybin remains a Schedule I substance under US federal law (Oregon Health Authority, services). More on the state systems is in Oregon and Colorado psilocybin programs explained.

How does this map to the legal routes in Canada?

Health Canada says production, sale and possession of magic mushrooms are illegal and that no psilocybin therapeutic product is approved. It describes three pathways through which, “with the support of a regulated health care practitioner”, a person may legally access psilocybin: clinical trials, the Special Access Program, and individual subsection 56(1) exemptions under the Controlled Drugs and Substances Act (Health Canada). New federal regulations took effect on 1 October 2026; the page, updated on 20 October 2026, names them only in a sentence on clinical trials, and our Canada guide covers that change.

• Clinical trials. Health Canada calls them the first legal route to pursue; they must be approved by a research ethics board and use drug made to Good Manufacturing Practices (Health Canada). This is where the protocols above apply in full. The COMP006 phase 3 registration lists Canadian sites, including CAMH and St. Michael’s Hospital in Toronto and sites in British Columbia and Quebec (ClinicalTrials.gov NCT05711940). See psilocybin clinical trials in Toronto.
• Special Access Program. A practitioner, not the patient, asks Health Canada for an unapproved drug for a serious or life-threatening condition when conventional therapies have failed, are unsuitable or are unavailable. There is no guarantee of approval (Health Canada). How the session itself is run under an authorization is set by the practitioner, not by a trial protocol. Details: the Special Access Program for psilocybin.
• Section 56(1) exemptions. A discretionary exemption by the Minister of Health. Health Canada says requests tied to a medical condition should include a practitioner’s letter of support showing why the other routes are unavailable or unsuitable (Health Canada). Details: section 56 exemptions for psilocybin.

What exists in this province, and what it costs, are covered in psilocybin therapy in Ontario and psychedelic therapy costs in Toronto. Retreats and storefront “therapy” sit outside all three routes.

What is still unknown?

• Which parts of the package matter. Preparation, the drug, the therapist and integration are delivered together, and the consensus authors say their effects cannot yet be separated.
• How much support is needed. Hours of preparation and integration differ widely between protocols, and no standard has been settled.
• Who it suits. Trials exclude many people, including those with bipolar or psychotic disorders or a family history of them, so results say little about them.
• How to train and check practitioners. The consensus statement says there is no standardized way to evaluate competence yet.
• Whether trial safety records hold outside trials, where screening and supervision may be different.

For background on the compound itself, see what magic mushrooms are and what psilocybin is.

Shroomverse sells mushroom products. This article is general information about clinical research protocols and regulations. It is not medical, legal or purchasing advice, and it does not recommend any product.