A 2005 magazine survey of club goers in the UK found that nausea or vomiting was experienced by over a quarter of those who had used psilocybin mushrooms in the last year .
This effect is caused by the mushroom rather than psilocybin itself .
A 2005 magazine survey of club goers in the UK found that nausea or vomiting was experienced by over a quarter of those who had used psilocybin mushrooms in the last year , although this effect is caused by the mushroom rather than psilocybin itself .