A Unique Team With A Unique Vision

Synthesis offers safe, legal, medically supervised psychedelic retreats in Amsterdam. We make the psychedelic experience accessible for curious individuals who want to utilize moderate-to-high doses of 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.


Synthesis spearheads a new era in the integration of psychedelics into modern culture. In professionally curated settings, these remarkable molecules can be agents of transformational experiences. Psychedelics have the potential to restore our sense of wonder and foster a renewed sense of connection; to ourselves, others, and the natural beauty of the wider world.
“Our name is a tribute to our core mission; providing an integrative approach to transformative wellness synthesizing modern science and medicine with wisdom traditions, ancient shamanistic rituals, and spiritual practices.”
Through workshops and ceremony, open-dialogue, bodywork, meditation, sound and psychedelic education, led by our professional facilitators, psychedelic experiences have the power to restructure thoughts, sharpen perceptual lenses, and awaken expanded forms of consciousness. This sense of possibility is what you will discover at Synthesis; a locus for profound transformation.
Lead Retreat Team

Natasja Pelgrom

Spiritual Care | Wellness Retreat Director

Throughout her professional development, Natasja maintained strong ties to her innate sense of spirituality, by concurrently studying energy healing, Reiki, ThetaHealing®, emotional freedom techniques (EFT), neuro-linguistic programming (NLP), and till today receiving sacred teachings from Native American and North European Shamanistic lineages.

She is a highly intuitive guide and has trained, assisted and facilitated in 500+ psychedelic ceremonies. As a medicine woman operating internationally, she curates medicine retreats, teaches empowerment workshops and developed a psychedelic integration and Self-Love program.

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Daan Keiman

Daan Keiman

MA Spiritual Care | Lead Facilitator, Director of Ethics and Advocacy

Daan holds an MA in Spiritual Care and has years of professional experience working in mental health and addiction care. He is the co-founder of Guild of Guides Netherlands: an organisation that seeks to professionalize psychedelic sitting services. His experience with guiding and caring for people in altered states of consciousness spans over a decade; ranging from psychedelic harm reduction work on festivals to his private practice as a Psychedelic Chaplain.

Daan draws from his personal Buddhist practices, psychedelic research and his professional experiences to create compassionate and powerful containers for personal and relational transformation. As an avid explorer of consciousness, he is highly capable of supporting others who are traversing the landscapes of the mind.

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James Clifton

James Clifton

Integral Psychotherapist, Dip-Psych, MBACP | Lead Facilitator

For more than 3 decades James has studied many of the world's perennial philosophies and engaged fully in a number of the great wisdom traditions, with specific interest in non-ordinary states of consciousness.

Trained formally in transpersonal psychotherapy and integral coaching and working with trauma and addiction, he is experienced at tracking tension and points of change and growth in individuals and groups. This unique experience allows him to fully understand the role of psychedelics and entheogen’s as a catalyst for authentic transformation.

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Co-Lead Retreat Team
Tessa Van De Ven

Tessa Van De Ven

Co-Lead Facilitator

In her role as co-lead facilitator, Tessa takes individuals on introspective journeys to connect with their true authentic self. Psychedelics entered her world when she experienced a challenging identity crisis and sought out nature-based healing modalities.

This exploration of self-healing led her towards various traditional and modern psychedelic ceremonies working with skilled guides and studies in the transformative potential of natural compounds. Tessa's strong intuitive abilities, empathy skills and deep connection with psychoactive plants make her an excellent guide on your journey through expanded states of consciousness.

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Sven Kimenai

Sven Kimenai

BSc. Psychobiology | Co-Lead Facilitator & Breathwork Coach

Sven has a background in Psychobiology & Supplement Development. After his studies, he went on a path of exploring science-based methods for self-healing. He became a Wim Hof Method Instructor, a Breathwork Facilitator and started studying Psychedelics for transformational healing.

He emphatically empowers others to step out of their comfort zones and supports them in exploring their inner landscapes. His aim is to research and apply psychedelics and breathwork, to catalyze personal growth, insight & human connection.

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BSc. Psychology | Co-Lead Facilitator

Roos-Veerle has her background in psychology but also studied many different (eastern) healing modalities. Since 2020 she is the owner of a conscious enterprise in the heart of Amsterdam; ‘Roots & Wings’. In her lifework and business, she favours a holistic approach to human wellbeing to enable a safe container for the further exploration of the mind-body-spirit connection. What Roos-Veerle does is to assist people to evolve as a human being in consciousness (with more ease, joy and glory) instead of evolving in suffering, dis-ease or exhaustion.

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Assistant Retreat Team
Marta Kaczmarczyk

Marta Kaczmarczyk

MSc. Cognitive Science | Retreat Assistant

Marta is a cognitive scientist (MSc) who has been exploring the concept of the mind from the perspective of science but also Jungian psychology, mindfulness, and somatic therapy.

She co-founded a non-profit psychedelic-oriented community platform and has been giving lectures on psychedelics, focusing on informed use and harm reduction.

Additionally, Marta is a biohacking consultant and a psilocybin truffles guide. In both of these activities, she supports people with the opening to the message of emotions and feelings, to find a fuller life.

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Odin Pepper

Retreat Assistant

Odin is a Dutch-American, born and bred in Amsterdam. For the past decade, he has worked as a cinematographer after earning his Bachelor of Arts degree at the Dutch Film Academy.

For the past few years, he has been on a path of self-exploration, self-development, healing, and trauma processing. He has been exploring different modalities and methods like tai-chi, reiki, the healing properties of psychedelics like ayahuasca and psilocybin containing truffles, meditation and different forms of movement therapy. He's recently completed a 2-year intensive course as a certified AuraTouch practitioner.

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Hanneke Meesters

Retreat Assistant

Hanneke began working with psychedelics in 2012. She discovered the therapeutic work of plant medicine in combination with ceremonial practices after spending time in the Guatemalan jungle where she studied the Mayan culture, herbal medicine, and Shamanism. After this beautiful and intense experience, Hanneke decided to combine her own intuitive skills with psychedelics and lifestyle coaching. Since then she has been working with individuals and groups as a coach and retreat facilitator using plant medicines, bodywork, and mindfulness practices to nurture alignment and synchronization.

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Jeff Hamburg

Retreat Assistant

Jeff’s arrival in the healing space occurred last decade when suddenly hypnotherapy, Holotropic Breathwork, psychedelics and Itzhak Beery, his shamanic teacher, almost simultaneously entered his life.
Jeff is a classical composer as well which has often taken him via his music into the inner world. By combining all of these modalities, he has developed an uncanny skill of navigating these inner worlds as well as creating a safe space for others to explore their own inner dimensions.

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John Newton

Retreat Assistant

John has widely studied the field of Transpersonal psychology and philosophy, and has a passionate interest in psychedelics, meditation and awakening. 
He has worked in clinical research with psychedelics, harm reduction services, and has a wealth of experience in providing psychological care, especially in supporting those undergoing challenging psychedelic experiences.   
Formally trained as a mindfulness coach, John is a long term meditation practitioner, and is deeply committed to supporting personal insight in service of collective transformation.
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Alexander Beiner

Holistic Counselor | Retreat Assistant

Alexander is a trained meditation instructor and Holistic Counselor, with a decade of experience guiding people through powerful personal development processes. As well as co-founding a meditation studio in London, he is co-founder of Rebel Wisdom, through which he runs men's retreats that have been covered by the BBC and the Guardian. As a director of Breaking Convention, Europe's largest conference on psychedelic medicine, he is a proponent of safe, ethical and transformative psychedelic experiences.  

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Venue Team

Maria Petit

Venue Manager

Former Motorola Ltd Commercial Director Europe Middle East and Africa. Maria left the corporate world in 2009 on a two year sabbatical which led her to study Arabic in Yemen, play polo in Argentina and launch her first start-up JAM Language. During the decade that followed, Maria lived in the United Arab Emirates, Mexico, Jordan, Yemen, Spain, Argentina and Brazil where she co-founded the events company SPNM.

Afterwards she embraced a minimalist lifestyle as a digital nomad chasing the summer between Europe and South America. This period led her down a road of self discovery which included living in Osho meditation communities in Germany and in Uruguay, attending Humaniversity and getting certified as a Human Potential Coach.  Coaching in the areas of Wellness, Performance and Lifestyle.


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Health & Psychological Support Team

Dr. Rosalind Watts

Clinical Director

Rosalind is the former Lead Clinical Psychologist at Imperial College London’s Centre for Psychedelic Research. Her clinical team has been pioneering research in the therapeutic potential of psilocybin, particularly for depression and disconnection.

Rosalind has developed a psychedelic therapy model ‘Accept, Connect, Embody’, and a psychometric measure of ‘connectedness’ which her qualitative research identified as a mechanism of therapeutic change in psychedelic approaches. Collecting data from our participants, her research has recognised consistently positive outcomes for people attending Synthesis retreats. Rosalind will use her expertise to optimise the Synthesis retreat model, continue scientific research and develop a clinical model to help more people with mental illnesses in the future.

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David de Wied

MSc. Clinical Psychology | Health Screener

David graduated from Utrecht University in the fields of Clinical Psychology and Cognitive Neuroscience. His research has been focused on set and setting factors such as the role of music and the effects of different social and physical contexts on the psychedelic experience, a collaborative project with Imperial College and the Psychedelic Survey.

At Synthesis he performs exploration calls and is a member of the medical screening team, utilizing his clinical expertise in helping determine if people should come attend the retreat. David is particularly fascinated by visionary experiences and cognitive changes from psychedelic experiences, as well as finding the right therapeutic approach to work alongside these medicines.

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Maria A

Maria Amato

MSc. Cognitive Neuroscience | Researcher & Health Screener

Maria holds a master degree in Cognitive Neuroscience and has a background in molecular biology. She carried out both fundamental and clinical research, investigating the immune system, the role of neurotransmitters in the brain, and emotional processes in people with ADHD.

Maria has entered a path of self-exploration through meditation and the study of Eastern religions and philosophies. Her passion for psychedelics developed together with her scientific curiosity towards the mysteries of the brain. She sees her own psychedelic experiences as life-changing
and hopes for a world where science and spirituality can come together for the awakening of human consciousness. 

She is in love with nature and spent the last year fighting climate change both as activist and educator. As part of the medical screening team, Maria carries out scientific research with the aim of improving the physical and mental health of people joining the Synthesis retreat.


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Floor Janssen

MSc. Behavioral Science | Medical Screener

Floor is a behavioral scientist that graduated from Radboud University. She specialized in Affective Neuroscience and Experimental Psychopathology & Treatment. Furthermore, her background lays in interdisciplinary research, behavioral change, and bias in decision making. 

As a member of the health screening team at Synthesis, her focus lays in the wellbeing and safety of people attending the retreat. Her main interests are optimizing mental health and the therapeutic potential of psychedelics. 

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Rosanna Ellis

MSc. Palliative Care | Clinical Administration

Rosanna has worked in healthcare for over a decade and has a background in intensive care and hospice Nursing. She has an MSc in Palliative Care and has researched the use of psychedelics for the treatment of anxiety and depression in people with advanced diseases.

Through her work in hospitals and hospices, Rosanna recognized a need for novel ways of approaching mental health problems and believes that psychedelics have the potential to change the therapeutic paradigm of mental health care. 

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Corporate Team
Melissa Watkins

Melissa Watkins

Operations Manager

Melissa has a broad background in operations. Before joining Synthesis, she managed a luxury diving resort in the Philippines, supported a large scale IT implementation in a Dutch hospital, and earned her stripes as a project manager at an international marketing agency.

With over 10 years of personal experience working with psychedelics ceremonially, she’s bringing her process management and coordination skills to Synthesis.

While not oiling the wheels in our corporate office, or holding space during our retreats, Melissa is working towards her degree in Psychotherapy, specialising in embodiment, sexuality and psychedelic-assisted therapy.

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Jakobien van der Weijden

Jakobien van der Weijden

Customer Service Manager

Jakobien is a Media Studies graduate and former marketer who has been in service of the psychedelic renaissance since 2003. She co-founded a microdosing information platform and has been part of several psychedelic research organisations in the Netherlands.

At Synthesis she supports our attendees on their pre and post retreat journey. When not connecting with you for your exploration call or running corporate operations, she is a Holistic Health Coach in training. She has a strong belief that through the therapeutic use of psychedelics we can activate our inner healing intelligence.

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Operations Support Manager

Arin has a background in business, leadership development and yogic philosophy, and has spent most of her career as a startup Founder working on projects to scale healing and transformative experiences.

She is a Reiki Master Teacher, and is certified as an integrative psychosomatic coach with special concentration in relationships and sexuality. She believes business is a powerful vehicle for positive change and that change has to start at the heart of business: its people and it's leaders.

Her journey with Psychedelics began in Peru's Sacred Valley, and she is passionate about bringing more integration and balance to the healing journey through embodiment and self-care.

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Financial Controller

Ethan is the financial controller at Synthesis. Over the past 15 years, he has worked in the private sector managing community-based projects for start-ups, state and federal government projects in the U.S. Ethan is especially passionate about conscious organizational strategy in the psychedelic space, financial modeling and providing data-driven insights to inform strategic, financial, and operational decision-making across the company.

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Austin Piedmont

Digital Media Manager

Working for his first start-up while still in high school, Austin prides himself in his creativity and storytelling abilities. Being a hands-on learner, he taught himself skills such as web design, photography, videography, and graphic design - to name a few.

When he's not working, Austin spends his time with his wife and three children. His hobbies include jiu jitsu, video games, and reading philosophy. He also volunteers at the organization he founded, The Collective Unconscious, which focuses on improving the psychological well-being and development of university students.

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Jessica McCulloch

Content Marketing Specialist

Jess has worked in many marketing and writing positions in the arts, architecture, tech and luxury global FMCG brands over the last five years.

With a passion for the integration of science in the arts, Jess received a first-class honours degree and a writing award in History of Art, and earned a Masters in Design, Culture and Society. In her free time, she’s the Editor-in-Chief of a Bioart foundation called Unbore Collective, and loves exploring galleries and museums.

Jess is happy to work for a conscious startup that contributes to social good. She brings inspiring editorial about the science and stories of psychedelics to our curious audience.

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Christopher Koutsouvelis

BSc. Accounting | Financial Accountant

Chris has spent his career at many firms performing multiple roles over the last 5 years including EY and Morgan Stanley. He holds multiple accounting degrees and honours in South Africa, with eligibility to register as a Chartered Accountant. He also started his own small business and is a highly entrepreneurial thinker.

Chris is passionate about improving the well-being of fellow man and the advancement of consciousness. He is excited to see the benefits of safely introduced psychedelics into a new world and is committed to help create a more connected future. When not accounting he is an avid movement enthusiast and spends his spare time building a mind body awareness through gymnastics, yoga, meditation and breathwork.

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Lucy Nightingale

Product Manager

Lucy has over 15 years experience working in mental health, her career began working in psychiatric hospitals. In more recent years, Lucy founded an international organisation that for 10 years has sent over 8000 aspiring mental health practitioners across the world to support and learn from local organisations committed to improving the mental wellbeing of their communities.

Being exposed to various cultures' different mental health treatments ignited Lucy’s passion for exploring alternative medicines, which led to her interest in the therapeutic potential of psychedelics.

Lucy finds clarity and grounding from her yoga and meditation practice and is deeply grateful for her personal experiences working with plant medicines. 

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Julia Piedmont

Retreat Support Manager

Julia's background is rooted in psychology and caretaking. Between the United States and Europe, her career has involved many roles supporting mental health. This includes working in a drug and alcohol addiction rehabilitation center, being a caretaker for a woman with severe brain damage and paralysis, working with children with special needs, coaching individuals facing a variety of mental challenges, and more.

After Julia experienced some difficult challenges herself, psychedelics sparked a transformation in her that was life-changing. Through Synthesis she is able to bring her knowledge and skillset together with her support for psychedelics as a tool for healing and growth.


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Management Team


Co-Founder & Chief Visionary Officer

Martijn has driven the vision of Synthesis Institute since he co-founded the company in 2018. As CEO for two years - and now as Chief Visionary Officer - he has stewarded Synthesis through the early concept to maturity with the vision of making psychedelic tools accessible in a safe, legal, and modern context. Under Martijn's leadership, Synthesis has heralded a world-class, professional standard for psychedelic wellness and mental health. 

Having previously co-founded HighExistence and Apotheosis, Martijn is an experienced entrepreneur in the wellness and transformative space. As a writer, speaker and interviewer on psychedelic subject matter, he was one of the first in the space to anticipate the microdosing revolution in early 2014.  

Applying his academic background in interdisciplinary science and philosophy, his work and identity as an entrepreneur is strongly influenced by eco-phenomenological thought, and by his decade-long personal practice with Buddhism and Shamanism. He is currently focused on scaling opportunities for flourishing, well-being, and transformation through the synthesis of contemplative practices, immersive technology, and psychedelics. 

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Co-Founder & Director of Business Development

Myles has spent his career on three different continents launching or leading VC-funded startups with technological, socially responsible, and green initiatives.

He has a strong belief that business and capitalism, when incentivized correctly, can be the most powerful tools we have to make positive, sustainable change in our modern society, and is excited to bring his experience to the psychedelic movement.

Specifically with Synthesis, Myles looks forward to developing an impact-focused business model that increases access to safe, legal and professionally-guided psychedelic experiences and sets an example for what a psychedelic-integrated future can look like.

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PhDc. | Chief Executive Officer

Rachel is a serial entrepreneur, conscious business and leadership coach, speaker, and conscious social change facilitator with nearly 20 years of experience working with clients across the U.S., Europe and East Africa.

In addition to her passion for conscious business and leadership, Rachel is focused on the transformation of trauma into action and leadership. Her practice includes a variety of modalities integrating body, breath, meditation, and creative arts-based practices.

Rachel holds a B.A. in Transformative Education & Leadership and a M.A. in Clinical Mental Health and Mindful-Trauma Informed Leadership. Rachel is currently working on her PhD in Integral/Transpersonal Psychology.

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Advisory Board

Dr. Robin Carhart-Harris

Advisory Board Member

Robin is the Head of the Centre for Psychedelic Research, in the Department of Brain Sciences at Imperial College London, where he has designed a number of functional brain imaging studies with psilocybin (magic mushrooms), LSD, MDMA (ecstasy) and DMT (ayahuasca), plus clinical trials of psilocybin for treatment-resistant depression. His scientific contributions to psychedelic-assisted therapy could play a significant role in the future of psychedelics for mental health care.

Robin states that scientific investigation into the therapeutic potential of psychedelics is vital for combating the mental health crisis. As a partner with the center, scientific research shows that the Synthesis experience was found to significantly reduce symptoms of anxiety and depression, improve sense of wellbeing and emotional stability, and increase connection to self, others and nature. Legal, professionally-organised retreats like Synthesis can be a safe way for people to experience the transformational potential of psychedelics, and they can also be a great source of data for research, helping to further advance the field. Robin is excited to continue working alongside Synthesis to provide high-quality services and meaningful scientific research for the psychedelic community.

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Dr. Beatriz Caiuby Labate

Advisory Board Member

Dr. Beatriz Caiuby Labate (Bia Labate) is a queer Brazilian anthropologist based in San Francisco. She has a Ph.D. in social anthropology from the State University of Campinas (UNICAMP), Brazil. Her main areas of interest are the study of plant medicines, drug policy, shamanism, ritual, and religion. She is Executive Director of the Chacruna Institute for Psychedelic Plant Medicines (http://chacruna.net). She is Public Education and Culture Specialist at the Multidisciplinary Association for Psychedelic Studies (MAPS), and Adjunct Faculty at the East-West Psychology Program at the California Institute of Integral Studies (CIIS). She is also co-founder of the Interdisciplinary Group for Psychoactive Studies (NEIP) in Brazil and Diversity, Culture and Ethics Advisor at the Synthesis Institute. She is author, co-author, and co-editor of twenty-one books, two special-edition journals, and several peer-reviewed articles.

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Tero Isokauppila

Advisory Board Member

Tero is the CEO and Founder of Four Sigmatic, a global superfood company helping people to elevate their wellness with adaptogenic mushroom ingredients. He is also the author of two best-selling books Healing Mushrooms and Santa Sold Shrooms.

A respected expert in the industry, Tero speaks at various events and was chosen twice as one of the world’s Top 50 Food Activists. Tero believes that professional, legal and modern contexts like Synthesis are making psychedelic experiences more accessible to help people gain the benefits of greater connection, personal healing and meaningful insights from a single dose.

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Tura Patterson

Advisory Board Member

Tura builds upon her background in business development in leading the cultivation and management of strategic relationships for Usona Institute. Tura engages directly in identifying and fostering key relationships with research collaborators, donors and regulatory partners to ensure streamlined and well-managed alignment with Usona’s clinical program goals as well as new drug discovery and research initiatives.

Prior to Usona, Tura worked as a business development consultant with specialization in strategic planning, development of new markets and services, sustainable design and global engagement for high-technology, non-profit, academic and professional service organizations. Within that role, Tura applied her expertise in facilitation, creative thinking, and organizational development to position clients through innovative partnerships and new collaboration opportunities.

Tura has bachelor’s and master’s degrees in International Economic and Commercial Relations and Scandinavian Studies from the University of Wisconsin-Madison, and is an LEED Accredited Professional.

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Dr. Bennet Zelner

Advisory Board Member

Bennet researches, teaches, and advises on regenerative economics, the delivery of psychedelic-assisted mental healthcare, and institutional change. He serves as Associate Professor of Business and Public Policy at the Robert H. Smith School of Business at the University of Maryland, College Park. He is also co-founder of a new organization, the Transformative Capital Institute, that funds and collaborates on projects supporting the emergence of regenerative communities and the production of well-being. Bennet is a frequent presenter at conferences and seminars, and his article on the “Pollination Approach” to delivering psychedelic-assisted mental healthcare appeared in the Spring 2020 of the MAPS Bulletin. In addition to serving on the Synthesis Board of Advisors, Bennet advises the Usona Institute, MAPS, the MIND European Foundation for Psychedelic Science, Sage Integrative Health, and Enthea. Bennet received his bachelor’s degree from Brown University and his PhD from the University of California at Berkeley.

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Join The Synthesis Team