Truffles are the firm, underground part of certain fungi, and unlike mushrooms they are legal in the Netherlands. At Stars Frequencies in Amsterdam, Rosa works with truffles only within a guided truffle ceremony: a day of about 7 hours in a small group of at most 8 people (€295 per person) or privately (€495).
When people in the Netherlands talk about truffles in this context, they don't mean the expensive truffle you grate over pasta. They mean sclerotia: small, firm knots that certain fungi form below the ground. You could see them as the fungus's store of energy, a compact form that can survive dry or cold periods.
These truffles contain the same substances as the mushrooms that grow above ground from related fungi: psilocybin and psilocin. The difference that matters most in the Netherlands is not biological but legal. More about that below, and in the comparison between truffles and mushrooms.
On this page you'll find what truffles are, what they can do, what the risks are and why the setting makes such a difference. Plain information, without promises. If you want to know what a guided day looks like, read what a truffle ceremony is.
Yes. Truffles are legal in the Netherlands. They are not named in the Opium Act, the Dutch law that lists which substances and products are banned. Mushrooms that contain psilocybin are a different story: both dried and fresh mushrooms are on list II of the Opium Act, and fresh ones have been banned since 2008.
Stars Frequencies only works with legal truffles. Legal does not mean harmless, though. The law says something about what is allowed, not about what is wise for you. That second question is what the intro call is for. You can read more about the legal side of a truffle ceremony.
No. Because truffles are not named in the Opium Act, they are legally neither a hard drug nor a soft drug. The substances psilocybin and psilocin themselves are on list I, the list of hard drugs, and mushrooms containing them are on list II. Truffles fall outside both lists. Jellinek and the Trimbos-instituut, two independent Dutch sources, explain this in more detail (see the sources at the bottom of this page).
Truffles change how you perceive things for a number of hours. Independent information from the Trimbos-instituut describes that reality starts to feel different, that music and sounds can come in intensely, and that thoughts are experienced differently. Something that normally seems simple can suddenly feel complicated.
Participants at Stars Frequencies often describe it in plainer words: they feel more than they're used to. Emotions that were kept at a distance come closer. Some people see images with their eyes closed, others mainly notice their body. For people who run their life from their head, that can be unfamiliar. It's also often why they come.
There are physical effects too. Trimbos mentions relaxed muscles, large pupils, headache and nausea. It's good to know about nausea beforehand, so it doesn't frighten you if it comes.
The main risks are psychological. You can feel anxious, confused or restless for a while, and something that has been pushed away for a long time can come up. In people with a vulnerability to psychosis, truffles can trigger one, and some medication combines dangerously with them. That's why screening, a calm setting and someone who stays with you are the foundation, not extras.
A ceremony is not a replacement for medical or psychological care. Read more about safety
There is no single answer, and we'd rather not give you a number that turns into something to watch the clock for. How quickly you notice something differs per person. It depends on your body, on what you've eaten, on how tense or relaxed you are, and on the truffles themselves. Some people notice a change fairly soon, for others it comes on more slowly.
What helps more than a number: knowing that the effect usually comes on gradually rather than all at once, and that you don't have to do anything to make it happen. In the intro call Rosa explains how the day unfolds, from arriving to going home, so you know what to expect at each stage. On the day itself she's in the room the whole time, so if you're unsure whether something is starting, you can ask her.
The whole ceremony day at Stars Frequencies takes about 7 hours. That gives the experience time to come, to settle and to wind down, without rushing anything.
Truffles are legal, so some people take them on their own, at home or with friends. The substance is the same. What's different is everything around it.
| On your own | In a guided ceremony | |
|---|---|---|
| Beforehand | No one checks your medication or health | A free 30-minute intro call with screening for medication and contraindications |
| The amount | You guess | We tune the amount to you together in the intro call |
| The setting | Wherever you are, with whatever is going on around you | A calm, prepared room in Amsterdam, in a small group of at most 8 people or private |
| Support | Friends who may be having their own experience | Rosa is in the room for the whole ceremony, and there is an emergency protocol |
| Something to hold on to | Mostly your own thoughts | Meditation and sound healing with live singing bowls, a fixed part of every ceremony |
For someone who wants to stay in control, that difference matters. Letting go isn't a condition. It's a consequence. It tends to happen more easily when you know someone is watching over the space, when you don't have to arrange anything yourself, and when your mind has something to follow. That's how a guided truffle ceremony is set up.
Research into psilocybin, the substance in truffles, has picked up again in recent years, including studies into psychological complaints. The Trimbos-instituut notes that in such studies people receive intensive guidance from trained professionals. The research is ongoing and the outcomes are still being studied.
That's worth saying clearly: research in a clinical setting is not the same as a ceremony, and it is no reason to expect a particular result. At Stars Frequencies we don't promise outcomes. What we can describe is what participants tell us afterwards, and how the day is built to keep it safe and calm.
Truffles are not for everyone. A ceremony isn't responsible if:
With SSRIs and SNRIs the effect can be strongly reduced or unpredictable, so always bring them up. Never stop medication on your own. Rosa goes through all of this in the intro call and honestly says no if it isn't responsible. Everything about screening is on the safety page.
Yes. Truffles are legal in the Netherlands because they are not named in the Opium Act. Mushrooms, which contain the same substances, are on list II of the Opium Act and are banned. Stars Frequencies only works with legal truffles.
No. Legally, truffles are neither a hard drug nor a soft drug, because the Opium Act doesn't name them. The substances psilocybin and psilocin themselves are on list I, and mushrooms containing them are on list II. Legal does not mean without risk, which is why screening beforehand matters.
Not quite. Truffles are the firm knots certain fungi form below the ground, and mushrooms are what grows above it. They contain the same substances, but in the Netherlands truffles are legal and mushrooms are not.
Physical side effects can include nausea, headache, relaxed muscles and large pupils. The main risks are psychological: feeling anxious, confused or restless for a while, and in people with a vulnerability to psychosis truffles can trigger one. That's why Rosa screens everyone in the intro call and stays in the room for the whole ceremony.
It differs per person, and it depends on your body, what you've eaten, how tense you are and the truffles themselves. Rosa explains how the day unfolds in the intro call, so you know what to expect. On the day she's in the room the whole time, and you can ask her whenever you're unsure.
We tune the amount to you together in the intro call. It isn't a competition, and you don't have to go as deep as possible. Tell Rosa what you find scary and she takes it into account.
About half of the participants are doing it for the first time. No experience needed. You start with a free 30-minute intro call and get preparation for at home.
Write to Rosa to ask whether a ceremony in English is possible for you. You can do that in the same message in which you plan the free intro call.
In a free 30-minute intro call Rosa listens to where you stand and goes through your health and medication. You decide afterwards, in your own time. Write to Rosa to ask whether a ceremony in English is possible for you.
