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For people who tried

Ketamine · Spravato

If ketamine or Spravato did not help enough, or left you with unanswered questions.

Some people experience only partial or short-term relief. ONCE may be an option to explore next, with a different substance, a different setting, and deeper preparation and integration.

Start a confidential preliminary assessment
  • Professional screening
  • Supervised access in Amsterdam
  • No promises, no hype

The ONCE pathway is not a replacement for medical or mental-health care.

An armchair by a sunlit window, with a nasal spray, a medication box and a pill blister on a small wooden side table

You might be in the right place if:

Ketamine or Spravato did not help enoughThe benefits were limited or short-lived.
You are left with questionsAbout why it did not work as expected, or what comes next.
You want a different approachWith more preparation, psychological support and integration.
You are looking for what is nextA professionally supported pathway in Amsterdam, with screening at every step.

About the ONCE pathway

ONCE is a professionally supported pathway that combines psilocybin-assisted sessions with psychological preparation and integration.

It is not ketamine. The substance, the dose and the setting are different, and so is the surrounding psychological approach. It is not a treatment and makes no promise of a particular result.

Everyone begins with a confidential preliminary assessment to help understand your situation and whether this pathway may be appropriate for you.

  • Individual assessmentYou share what brings you here. We look at your mental and physical health, approaches you have tried, and what you hope this process might support.
  • Professional reviewQualified clinicians review your summary to consider suitability and risk. You may be invited for a screening conversation.
  • Preparation & in-person daysIf the pathway is appropriate, you continue with preparation, your in-person session in Amsterdam, and integration support afterwards.
  • Integration & follow-upYou are not alone after the experience. We support you in making sense of it and relating it to everyday life.
Learn how the pathway works

What research suggests

In controlled academic studies, some participants with persistent depressive symptoms reported meaningful improvement after psilocybin-assisted sessions, including people who had not found enough relief with other approaches.

Results vary between individuals and study populations. It is not possible to predict how any one person will respond.

See evidence and sources
40–60%of participants in some clinical studies of treatment-resistant depression responded to psilocybin-assisted therapy.Figure pending source verification
20–30%of participants reached remission (sustained improvement) in several clinical studies.Figure pending source verification

Research is evolving. ONCE does not promise specific outcomes.

Curious if this pathway could be relevant for you?

Start a confidential preliminary assessment

Takes about 4 minutes. You read your full summary before any contact details are requested.