The Matter
Culemborg, Gelderland
Boutique venue in Culemborg offering 4-day group retreats with two psychedelic truffle journeys, plus day retreats and one-to-one programmes.
Details from the centre's own website, read 28 Sep 2026. No independent source was found.
The legal position in Netherlands
Since 1 December 2008 List II of the Opium Act has covered psilocybin mushrooms, fresh and dried. Truffles, the underground sclerotia of some of the same species, are not on the list, and the Health Minister confirmed in 2011 that they fall outside the Act. The addiction service Jellinek says fresh truffles may be sold but dried truffles are treated as prohibited, so only fresh truffles have clear footing. A centre offering 'mushrooms' in the Netherlands is describing something the ban covers.
The sources for this
- The Decree of 17 November 2008 (Staatsblad 2008, 486), in force 1 December 2008, added hallucinogenic mushrooms to List II of the Opium Act. The explanatory note says freely available fresh mushrooms differ little in effects and risks from dried ones, which were already controlled after a 2002 Supreme Court ruling. (Overheid.nl Officiele bekendmakingen, 17 Nov 2008)
- The current List II entry 'Paddo's' covers "paddenstoelen die van nature de stof psilocine of psilocybine bevatten" (mushrooms that naturally contain psilocine or psilocybine), followed by a list of named species. It does not mention sclerotia. (wetten.overheid.nl, 1 Jan 2026)
- In an answer to parliamentary questions received on 28 December 2011, Health Minister Schippers wrote that psychedelic truffles or sclerotia do not fall under the Opium Act, and that this was known when 186 mushroom species were placed on List II on 1 December 2008. (Overheid.nl Officiele bekendmakingen, 28 Dec 2011)
- The Jellinek addiction service states that selling fresh sclerotia (truffles) is not prohibited, but dried truffles are treated as prohibited. (Jellinek, current page)
The law and every listed centre in the Netherlands
Programmes and cost
| Programme | Nights | Sessions | From |
|---|---|---|---|
| 4-day group retreat Per own site (Oct 2026, Nov 2026, Jan 2027 dates) | 3 | 2 | EUR 1,750as published on 28 Sep 2026 |
Prices and formats as published by the operator on the date shown. They change, so confirm directly before budgeting. We never estimate a price that is not published.
Screening, as the centre describes it
Not stated on the pages we read.
The cited psilocybin truffles safety facts to check it against
Accommodation
- Countryside venue with yurt, sauna and pool
What a psilocybin retreat involves
The typical shape of this kind of programme. Use it as a checklist to ask against, not as this centre's timetable.
- Before arrivalIntake questionnaire and medical screening. Reputable operators ask about SSRIs, lithium, cardiac history and family history of psychosis, and decline people accordingly.
- Day 1Arrival, group meeting, intention setting, one-to-one time with facilitators.
- Dosing daysSessions typically run in daylight over 4 to 6 hours, with facilitators present throughout. Doses are often escalated across sessions rather than kept flat.
- Between sessionsGroup integration discussion, bodywork or beach time, and rest. The day after a session is deliberately unstructured.
- Final dayClosing integration session and onward planning.
- AfterAsk specifically what follow-up is included and for how long.
Sources for this profile
- The Matter homepage · Centre's own site, read 28 Sep 2026
Also in Netherlands
- Beckley Retreats (Netherlands)De Hoorneboeg (Hilversum) and The Place to Be, Netherlands
- KiyumiDutch countryside (venue not named on site; press says near Amsterdam)
- Evolute InstituteLochem, Gelderland (Centrum Athanor)
- Experiential Training Institute (ETI)Amsterdam area
- Guided TrippingAmsterdam
- InwardboundCastricum area, North Holland (woodland venue about 45 min from Amsterdam)
- Tangerine RetreatLoenen (Apeldoorn area), Gelderland
All psilocybin retreats in the Netherlands, and the legal position there