Classic tryptamine psychedelic; FDA Breakthrough Therapy designation for depression.
Psilocybin is a naturally occurring tryptamine produced by a family of fungi most often called "psilocybin mushrooms" or "magic mushrooms." The best-studied species is Psilocybe cubensis, though around 200 species synthesize psilocybin or its close analogs. The molecule was first isolated and named by Albert Hofmann of Sandoz in 1958 — the same chemist who had synthesized LSD 20 years earlier.1
Psilocybin itself is a prodrug. Within ~15–30 minutes of ingestion the body dephosphorylates it into psilocin, a potent partial agonist at the 5-HT2A serotonin receptor. This is the mechanism shared with LSD, DMT, and ayahuasca, and the reason these four are grouped as "classic psychedelics" — pharmacologically distinct from ketamine (which acts on NMDA glutamate receptors) and MDMA (which releases serotonin rather than binding the receptor).
Mushroom therapy is the everyday name people use for psilocybin-assisted therapy — treatment built around a supervised dose of psilocybin, the active compound in "magic mushrooms," paired with preparation and integration sessions. It is the same thing clinicians and researchers mean by psilocybin therapy or psilocybin-assisted psychotherapy; "mushroom therapy" is simply the plain-language version of the phrase.
A mushroom therapist is, in practice, either a state-licensed psilocybin facilitator (in Oregon or Colorado's regulated programs) or a psychedelic-integration therapist who helps you prepare for and make sense of the experience. Outside those two state programs and approved clinical trials, supervised "mushroom therapy" is not yet legally available in the United States — the sections below explain exactly where it is legal, what the evidence supports, and how to access it honestly.
The protocol most psilocybin-for-depression trials use looks roughly the same across research groups (Johns Hopkins, NYU, Imperial College London, Usona Institute, COMPASS Pathways):
The dose itself is only a small fraction of the total therapist contact time. This — not the pharmacology alone — is the part many clinicians think drives outcomes.
Oregon voters approved Measure 109 in November 2020, and in January 2023 the state began licensing "psilocybin service centers." Participants over 21 can access psilocybin services at a licensed center without a prescription or diagnosis. It is not practicing medicine — Oregon explicitly positions it as non-medical supported use — and is not covered by insurance. Costs typically run $1,800–$3,000 per session depending on facilitator and center.
Colorado voters approved Proposition 122 in 2022, legalizing adult personal use of psilocybin and related tryptamines and establishing a state-licensed "healing centers" framework that began issuing licenses in 2025. Prop 122 is broader than Oregon's law in scope (covers psilocin, ibogaine, mescaline, and DMT) but similar in structure (licensed facilitator, designated location, no medical claims).
Psilocybin holds FDA Breakthrough Therapy designation for both treatment-resistant depression (COMPASS Pathways) and major depressive disorder (Usona Institute). Breakthrough designation accelerates FDA review but does not approve the drug. As of 2026, Phase 3 trials are ongoing; there is no FDA-approved psilocybin product.
COMPASS Pathways' Phase 2b trial (n=233, published in the New England Journal of Medicine in 2022) compared three doses (25 mg, 10 mg, 1 mg). The 25 mg arm produced a larger drop in depression scores at week 3 versus the 1 mg "active-placebo" control.2 At 12 weeks the between-group difference narrowed. This is the largest psilocybin-for-depression trial published to date. For how psilocybin's longer, therapy-heavy model compares to the fast-acting 5-MeO-DMT approach, see 5-MeO-DMT vs psilocybin.
A 2022 JAMA trial (n=104) compared 25 mg psilocybin to niacin placebo across 8 weeks of follow-up; the psilocybin arm showed a significantly larger reduction in depression severity at 6 weeks.3
Two well-known 2016 trials (Johns Hopkins and NYU, both published in Journal of Psychopharmacology) showed substantial reductions in anxiety and depression among patients with life-threatening cancer, with benefits persisting at 6-month follow-up in subsets.4 These trials are small but the effect sizes are among the largest reported for any psychiatric intervention.
A randomized, double-blind, placebo-controlled trial at the Yale OCD Research Clinic (enrollment 2018–2024) tested a single dose of psilocybin against an active placebo (niacin) in adults with treatment-refractory OCD. It was the first placebo-controlled RCT of psilocybin for OCD.8 The primary outcomes paper reported a clinically significant mean reduction in OCD symptom severity in the psilocybin group versus placebo at the 48-hour primary endpoint. This is a small, early-phase trial. It is not a basis for treating psilocybin as an approved or standard OCD treatment today. Up to 60% of people with OCD do not respond to standard first-line treatments, and this research aims at that gap.
Psilocybin has a favorable physiological safety profile compared to ketamine or MDMA. It is not physically dependence-forming. It does not produce the cystitis concern of chronic ketamine or the serotonergic concerns of high-dose MDMA. The main safety concerns are psychological and acute:
Drug interactions. Psilocybin's effects are reduced or blocked by SSRIs/SNRIs because both act on 5-HT2A. Any facilitator worth their license will ask about your current antidepressant regimen, and most will require a taper schedule before a session.
Not on current evidence. Small early-stage academic trials have begun exploring psilocybin in Alzheimer's-related depression, but there is no completed trial establishing psilocybin as a treatment for Alzheimer's disease, dementia, or autism themselves — none of the depression and cancer-related-distress trials cited above enrolled patients for those conditions. Dementia specifically warrants added caution rather than treatment: cognitive impairment complicates informed consent and the acute-anxiety risk profile above, and no dosing or safety protocol has been validated in that population. Readers researching an actual Alzheimer's or autism diagnosis should treat this as an open research question, not an available therapy.
Current clinical evidence does not establish psilocybin as an approved treatment for Parkinson’s disease. An open-label pilot trial in Neuropsychopharmacology administered 10 mg and 25 mg psychotherapy-assisted doses to 12 participants with mild-to-moderate disease, sustaining mood, cognitive, and motor gains for one month. No serious adverse events occurred, but 10 participants developed side effects like increased blood pressure, and researchers at UCSF are running a randomized controlled trial to verify the results.
Psilocybin is likewise unproven for borderline personality disorder (BPD). In a small open-label study of 10 adults with co-occurring major depressive disorder (MDD) and BPD, a single 25 mg dose improved depression symptoms without altering BPD-specific symptoms. Because emotional dysregulation presents screening and safety considerations, no validated dosing protocol exists for BPD, and readers should treat both diagnoses as open research questions rather than approved therapies. See the psychedelic integration guide for what responsible preparation and follow-up looks like for any of these early-stage protocols.
Psilocybin is a Schedule I controlled substance federally, defined as having no accepted medical use. The two exceptions to date are state regulated adult-use programs in Oregon (Measure 109, operational since 2023) and Colorado (Prop 122, operational 2025). These programs operate in tension with federal law — the DEA has not enforced against licensed state-legal operations, but the federal Schedule I designation remains unchanged. See our legal status by state tool for the current state-by-state map, or the dedicated Is psilocybin legal in Oregon? and Is psilocybin legal in Colorado? guides for the full detail on each program.
In April 2026, a presidential executive order directed the FDA to fast-track review of psychedelic treatments for veterans, naming psilocybin alongside ibogaine in its directive.6 This speeds up the federal review process; it does not itself reschedule psilocybin or change the Oregon/Colorado picture above.
Yes, in most states — spores themselves are a separate legal question from psilocybin. Spore syringes and spore prints contain no psilocybin or psilocin; the DEA has confirmed in writing that they are not controlled substances until they germinate. The moment spores grow into mycelium that produces psilocybin, that material becomes Schedule I, and germination is a federal felony everywhere. Four states — California, Florida, Georgia, and Idaho — ban spore possession or sale outright under their own state law. See our psilocybin spores legal guide for the full state-by-state table and vendor-shipping restrictions.
No. Psilocybin mushrooms are Schedule I under California Health & Safety Code §11054(d)(13) and under federal law. California has not passed any state-level decriminalization or therapeutic access program. Three bills have tried and failed or been vetoed:
Six California cities have passed entheogen deprioritization resolutions, directing local police to treat enforcement as the lowest priority: Oakland (2019, the first US city to do this), Santa Cruz (2020), San Francisco (2022), Berkeley (2022), Arcata (2023), and Eureka (2023).
See our California psilocybin legal status page for the current status of SB 751 and city-level deprioritization.
No. Psilocybin is Schedule I under Washington state law and federal law. Seattle, Port Townsend, and Olympia have passed deprioritization resolutions (not legal protections). Washington's Psilocybin Services Task Force completed a 2024 report recommending a licensed facilitator model similar to Oregon’s, but no bill has passed as of 2026.
No to all four. Each of these states has psilocybin as Schedule I under state law, mirroring the federal classification. Quick summary:
For a full state-by-state breakdown including Arizona, New Jersey, Nevada, Maryland, Alaska, and all other states, see the psychedelic legal status by state tool, or our legal psychedelics in the US guide for the federal-vs-state framework in one place.
Australia does not decriminalize or legalize psilocybin. Its medicines regulator, the Therapeutic Goods Administration (TGA), created a narrow clinical pathway for psilocybin therapy instead.
Effective July 1, 2023, the TGA moved psilocybin into Schedule 8, the category for tightly controlled medicines. The only approved use is treatment-resistant depression.
Access runs through the TGA's Authorised Prescriber scheme. A psychiatrist must apply for and receive TGA authorization before prescribing psilocybin. That psychiatrist then administers the dose in a supervised clinical setting.
This is a clinical prescribing pathway, not a retreat, ceremony, or self-referral service. There is no general public access and no take-home dosing. Booking requires a qualifying diagnosis and an authorized psychiatrist's approval.
No licensed psilocybin retreat operates in Brisbane, Perth, Sydney, or the Northern Rivers under this model. The TGA pathway does not include a retreat or ceremony format anywhere in Australia.
If your primary goal is depression treatment and you are comparing psilocybin with ketamine-family care, start with the depression treatment path. It separates FDA-approved Spravato, off-label IV/IM ketamine, at-home ketamine, psilocybin trials, and Oregon/Colorado services by legality, insurance, and next step.
If you are US-based, three paths exist today:
What this guide does not endorse is unregulated purchase of mushrooms or therapy from any provider who cannot tell you their license number, state of operation, and integration protocol. Wild-picked psilocybin mushrooms carry a separate risk we don't cover here: several deadly amanitin-containing species (notably Galerina marginata) share wood-substrate habitats with Psilocybe and have killed foragers who trusted field-guide ID. See our psilocybin mushroom identification safety explainer for why DIY ID alone is not a safe workflow.
As with ketamine, outcomes correlate more tightly with the quality of preparation and the post-session integration relationship than with the specifics of the dosing protocol. See the integration therapy guide for what this should look like.
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