Psilocybin has low physical toxicity and a low potential for dependence. A Dutch risk assessment rated acute toxicity as moderate and chronic toxicity as low, and named panic attacks and the setting of use as the main points of concern (van Amsterdam et al., 2011). The serious risks of a strong truffle are mostly psychological and behavioural: panic, confusion, accidents, and in a small group of people lasting psychological problems.
With a strong strain such as Hollandia those risks rise with the dose. In a survey of 1,993 people describing their most difficult psilocybin experience, 11% said they had put themselves or others at risk of physical harm, and the likelihood increased with the estimated dose (Carbonaro et al., 2016).
Who should not take Hollandia
Do not take truffles if any of the following applies to you:
- You, a parent, brother or sister have had psychosis, schizophrenia or bipolar disorder. Psilocybin can trigger an episode.
- You are going through a crisis, a recent loss or a period of severe stress.
- You have a heart condition or high blood pressure. Psilocybin can raise blood pressure, and anxiety during a trip can push up your heart rate.
- You are pregnant or breastfeeding.
- You are under 18.
- You take lithium or an MAO inhibitor (see below).
If you have never taken truffles, Hollandia is not a good first strain.
Dangerous combinations
Lithium. In an analysis of online experience reports, 47% of 62 reports of a psychedelic combined with lithium described a seizure, and 39% involved medical attention (Nayak et al., 2021). Do not combine them.
MAO inhibitors. These include some antidepressants and the harmala alkaloids in Syrian rue and ayahuasca brews. They can make psilocybin much stronger and longer lasting. With a strain that is already strong, that is a risk not worth taking.
SSRIs and SNRIs. These mostly weaken the effect (Gukasyan et al., 2023). The risk is that someone takes far more to compensate. Never stop prescribed medication to take truffles; discuss it with your doctor.
Alcohol and cannabis. Alcohol adds nausea and clumsiness and clouds judgement about how much you have taken. Cannabis can make a strong trip overwhelming within minutes, also during the comedown.
Other psychedelics and stimulants. Combining Hollandia with MDMA, LSD, ketamine or amphetamine makes the experience far less predictable. Take one substance at a time.
Physical effects to expect
Common and usually harmless: dilated pupils, yawning, cold hands or feet, nausea in the first hour, headache, muscle tension. In a controlled dose study with pure psilocybin, blood pressure rose moderately at the highest dose, about an hour after intake (Hasler et al., 2004).
The same study found that attention performance dropped by half at medium and high doses. That is why moving through traffic, cooking with fire, swimming or climbing is risky during a session.
Lasting effects
Most people are back to normal the next day. A small number report unsettling feelings or flashbacks for days or longer. In the survey above, 7.6% of those whose difficult experience was more than a year ago had sought professional help for psychological symptoms afterwards, and three cases appeared linked to lasting psychotic symptoms (Carbonaro et al., 2016). The authors note that such outcomes are very rare in laboratory studies with screened, prepared and supported participants. Screening yourself honestly, preparing and having support is the closest you can get to that at home.
Emergencies
Call 112 (in the Netherlands and the rest of the EU) if someone has trouble breathing, has a seizure, loses consciousness, is injured, or is a danger to themselves or others. Tell ambulance staff what was taken and how much. For non-urgent questions, the Drugs Infolijn of the Trimbos Institute answers on 0900-1995 (DRUGSinfo).
Read set and setting for preparation, or legal status before you travel.