Psilocybin and psilocin are indole alkaloids found in a variety of mushroom-forming fungi commonly referred to in North America as magic mushrooms. These alkaloid indoles are naturally occurring agonists of 5-hydroxy tryptamine 2A receptors located in the mammalian nervous system. In humans, the compounds cause a variety of psychotropic effects which can include altered states of consciousness and perception in addition to auditory and visual hallucinations with minimal systemic effects .