We choose every space with care — the process and the environment around it both matter.
PRICING
A clear price for every step
Most of the pathway takes place online.
One step takes place at the ONCE clinic in Amsterdam.
A private conversation about what brought you here, your questions and whether the pathway may be relevant to your situation.
* All listed prices include VAT.
* Travel and accommodation are arranged and paid for separately.
* Preparation and integration are billed per session, as the number of sessions varies by person.
* There is no single fixed package price.
* During the initial conversation, you receive a realistic estimate before anything is booked.
AW23
I participated in a private session on last December. Since day 1 the whole crew was amazing, professional, and compassionate. The combination of substance, along side the science and knowledge of the modern medical world, produced a whole and sacred experience, that was led by amazing people. It was beyond expectations. Definitely one of the most memorable and meaningful experiences of my life.
Jonathan Dekle
I was fortunate enough to attend a psilocybin experience with ONCE. In the last year I found the integrative approach more beneficial than other experiences I had tried. I needed more than the session itself, and the combination of care, therapy and continued support helped me stay engaged in the work of improving and the combination of care, therapy and continued support helped me stay engaged in the work of improving myself.
SAFETY
A growing clinical evidence base
30+controlled academic studies of psilocybin-assisted approaches in adults
A number of countries have created some route to supervised psilocybin-assisted work. The models differ widely in who may take part and on what basis, and none of them describes the ONCE pathway.
The NetherlandsPsilocybin-containing sclerotia are reported as not listed under the Opium Act.
AustraliaSince 2023, authorised psychiatrists may prescribe psilocybin for treatment-resistant depression under the national medicines regulator.
SwitzerlandSince 2014, individual exemptions granted case by case to authorised psychiatrists for severe conditions.
CanadaAdded to the Special Access Programme in 2022 for serious, life-threatening illness.
Oregon & Colorado, USState-regulated supervised service centres, outside the medical route and without a diagnosis requirement.
CzechiaLegislation reported as adopted in 2025 to permit medical use from 2026.
THE TEAM
The people behind ONCE
Alexander Lebedev, MD, PhDPSYCHIATRIST AND NEUROSCIENTIST
Alexander leads ONCE’s clinical and scientific approach, including screening, risk review and standards for considering suitability. He brings more than 20 years of clinical practice, research and leadership experience at European universities, and has authored over 100 peer-reviewed publications.
Maryna supports clients through online preparation and integration. She has experience working with psychological trauma and helps people explore conflicting emotions, protective responses and different parts of their inner experience before and after an in-person supported session.
Begin with a confidential preliminary assessment. It helps you organise what you are experiencing and identify questions that may need professional review.
Imperial College LondonNEJM · Randomised controlled trial · Major depressive disorder · 2021View study
Johns Hopkins School of MedicineJAMA Psychiatry · Randomised clinical trial · Major depressive disorder · 2021View study
University of ZurichEClinicalMedicine · Double-blind placebo-controlled trial · Major depressive disorder · 2022View study
Alexander Lebedev, MD, PhDPSYCHIATRIST AND NEUROSCIENTIST
Maryna MormulPsychiatrist · IFS psychotherapist
Vlad BakaliarCO-FOUNDER · PREPARATION AND INTEGRATION
Anton NedzvetskyCO-FOUNDER · INSPIRATION AND PROMOTION