The Synthesis Institute is a pioneering organization that offers both training and legal psychedelic sessions in The Netherlands. The services offered range from a weekend to 5-day retreats. The price does match the professional and scientific vibe.

With a proven track record for leading safe, legal, and medically supervised psychedelic retreats for over 1000 individuals, the institute has amassed years of data, experience, and anecdotal success stories. At its inception, the Synthesis Institute collaborated with Imperial College London to supplement its clinical research and with the California Institute of Integral Studies (CIIS) to provide hands-on experience for its students to become certified in psychedelic-assisted therapies and research.

With its reputation for offering world-class, legal psychedelic experiences and its involvement in psychedelic research, The Synthesis Institute is uniquely qualified to set the standard for practitioners to safely, ethically, and effectively support individuals on a journey for healing using truffles containing psilocybin.

The Company

“Synthesis offers legal, medically supervised, and scientific-based psychedelic retreats [near] Amsterdam. We make the psychedelic experience accessible for curious individuals who want to utilize moderate-to-high doses of psilocybin truffles to catalyze creative breakthroughs, explore consciousness, find meaning, improve confidence, and search for a mystical experience. Find out here what our customers say about us.”

Founded: 2018-04-01


  • Mental health (diverse)
  • Personal Growth

The Retreat

Synthesis offers 5 different retreats. The main retreat is the 3-day core retreat (as described below), this can also be done private (at a higher price). The other retreats all last 5 days and are for expansion, men, or women separately. The first day of the retreats are centred around the preparation and the last day around integration and sharing experiences.

“We offer an exclusive 3-day retreat [near] Amsterdam for individuals who want to utilize moderate-to-high doses of psilocybin truffles to catalyze creative breakthroughs, deepen self-understanding, and feel ready to make their next big ‘leap’ in life.”


  • Netherlands


  • 3 Days
  • 5 Days

Costs: from €2000 to €9000


  • Psilocybin (Mushrooms)

Group Size:

  • Private Retreat
  • 10-13 Participants
  • 14+ Participants

Guide Density:

  • 1 Participant per Guide
  • 5 Participants per Guide
  • 6 Participants per Guide

More information

Synthesis has access to four beautiful venues that they are using for the retreats.

They are working together with researchers at Imperial College London.

The advisory board is impressive and includes Robin Carhart-Harris and Rosalind Watts.

In July 2020 they raised $2.75 million to develop an end-to-end professional platform for psychedelic wellness & therapy.

Company Information

Synthesis Website

April, 2018


B2C Educational / Training Retreat

Compounds of Interest

Explore more company info with a Tree membership

📰 Weekly newsletter about the business of psychedelics
📈 Extended company information (analyst view, fundraising, revenue numbers)
🪄 Priority company page updates

Explore memberships

Related Course(s)

Psychedelic Practitioner Training
The Synthesis Institute's Psychedelic Practitioner Core Training is a 13-month educational program designed for professionals interested in contributing to the burgeoning field of psychedelic therapy.

Guiding the Unbound Mind
Guiding the Unbound Mind: What Every Practitioner Must Know About Working With Psychedelics, is an on-demand expert forum. This event is available at no charge and is designed to help practitioners safely and effectively incorporate psychedelics into their treatment protocols.

The Fundamentals of Psychedelics
The Synthesis Institute's The Fundamentals of Psychedelics, is an on-demand digital conference that will provide mental health professionals and practitioners with the foundational understanding of how to work safely, ethically and skillfully with psychedelics as a treatment option.


HQ / Office Weesperstraat 61, 1018 VN Amsterdam, Netherlands
Retreat Vuurse Steeg 1, 3749 AN Lage Vuursche, Netherlands
Retreat Spanbroekerweg 33, 1715 GH Spanbroek, Netherlands
Retreat Noorderstraat 2, 1901 MT Castricum, Netherlands