The Osiris Retreat
A 3-day guided prolonged fast in the Dutch countryside. Small group. Full support. Real results.
Overview
The Osiris Retreat is a structured, guided prolonged fast held in a small group setting in the Dutch countryside. Over three full days, participants are guided through the complete fasting arc — from preparation and release through to depth and renewal — with expert support, daily movement, breathwork, and group sessions throughout. The retreat concludes with a carefully designed refeeding meal, prepared to optimise reintroduction of food.
This is not a detox weekend or a juice cleanse. It is a serious, science-informed intervention — and for most participants, it is unlike anything they have experienced before.
How to join
Apply via contact form
Tell us a little about yourself, your health background, and what brings you to Osiris. There are no wrong answers — we just want to understand where you are.
Intake call
We schedule a 30-minute call to discuss your goals, your experience with fasting (if any), and any health considerations. This is a conversation, not an interview.
Medical screening
All participants complete a medical screening questionnaire. Certain conditions preclude participation for safety reasons — we explain these clearly and without exception.
Confirmation and preparation
Once confirmed, you receive a comprehensive preparation guide covering what to eat in the days before, what to bring, and what to expect. You arrive informed and ready.
Day-by-day program
Arrive at the venue and settle in. We gather as a group for a light welcome dinner (your last meal), a brief orientation, and an introduction to the days ahead. This evening is calm and unhurried — the fast does not begin until the morning.
The fast begins. The first day is often the most physically challenging, as the body works through its glycogen stores. We guide you through gentle morning yoga, a group sharing circle, and an afternoon nature walk. Electrolytes and warm bouillon are provided throughout. Evening: breathwork session and early rest.
By day two, most participants are entering or have entered ketosis. Energy stabilises. The mind quietens. This is often described as the most profound day. We go deeper with a longer morning movement session, a group discussion on the science of what your body is doing, and an extended afternoon in nature. Evening: a guided meditation on cellular renewal.
The final morning is gentle. A sunrise walk, personal reflection, and a group closing circle. At midday, we break the fast together with a carefully prepared refeeding meal — small portions, easily digestible, and nutritionally calibrated. You leave with a take-home guide, a post-fast protocol, and a clear plan for reintroducing food safely over the following days.
What’s included
Who this is for
- —Adults who have struggled with persistent fatigue, brain fog, or metabolic issues despite conventional approaches
- —People who have tried dietary changes and exercise but feel something fundamental is still off
- —Those curious about fasting who want the safety and structure of expert guidance
- —Anyone ready to commit fully to three days of rest, reset, and repair
Who this is not for
- —Individuals who are underweight or have a history of eating disorders
- —Those who are pregnant or breastfeeding
- —Individuals with type 1 diabetes or insulin-dependent conditions
- —Those with severe cardiac, renal, or hepatic disease
- —Anyone unwilling or unable to complete the pre-retreat medical screening
Frequently asked questions
Is it safe?
Prolonged fasting carries real physiological effects and is not appropriate for everyone. That is precisely why Osiris includes a medical screening process for every participant and why the retreat is guided, not self-directed. For healthy adults without contraindicated conditions, a 3-day water fast under proper supervision is well within the bounds of established safety profiles documented in clinical research.
Will I be hungry?
Yes — particularly on day one, as your body works through its glycogen stores. Hunger is typically a mental and habitual experience more than a physical emergency. By day two, most participants report that hunger has largely subsided as ketosis takes over. The group setting, movement sessions, and continuous support help significantly.
What if I can’t finish?
There is no failure in this process. Fasting is deeply individual. If at any point during the retreat you need to stop — whether for physical or personal reasons — we handle that with care, without judgment, and with a structured, safe reintroduction of food. Your wellbeing always comes first.
Do I need previous fasting experience?
No. Most participants come with no prior fasting experience beyond ordinary intermittent fasting, or none at all. The preparation guide, intake call, and guided structure of the retreat are specifically designed for people who are new to extended fasting.
Can I exercise during the fast?
We incorporate gentle movement — yoga, walks, and breathwork — which is both safe and beneficial during a fast. Intense exercise is not recommended and is not part of the programme. If you have a specific exercise-related concern, we discuss this during your intake call.
Pricing
Pricing will be announced once the venue and September 2026 dates are confirmed. Register your interest now to be notified first and to secure a place when booking opens.
Health disclaimer: This retreat is not a substitute for medical advice or medical treatment. Participants are required to consult their physician before attending. Osiris Retreats does not provide medical treatment, diagnosis, or clinical care. Individuals who are underweight, pregnant, nursing, or have a history of eating disorders should not participate. All participants undergo medical screening before their place is confirmed.
Ready to register your interest?
We’ll be in touch with more details, availability, and next steps.