Psilocybin effects are similar to those of other hallucinogens, such as mescaline from peyote or LSD. The psychological reaction to psilocybin use include visual and auditory hallucinations and an inability to discern fantasy from reality. Panic reactions and psychosis also may occur, particularly if large doses of psilocybin are ingested.
Hallucinogens that interfere with the action of the brain chemical serotonin may alter:
- sensory perception
- body temperature
- sexual behavior
- muscle control
Physical effects of psychedelic mushrooms may include a feeling of nausea, vomiting, muscle weakness, confusion, and a lack of coordination. Combined use with other substances, such as alcohol and marijuana can heighten, or worsen all of these effects.
Other effects of hallucinogenic drugs can include:
- intensified feelings and sensory experiences
- changes in sense of time (for example, time passing by slowly)
- increased blood pressure, breathing rate, or body temperature
- loss of appetite
- dry mouth
- sleep problems
- mixed senses (such as “seeing” sounds or “hearing” colors)
- spiritual experiences
- feelings of relaxation or detachment from self/environment
- uncoordinated movements
- lowered inhibition
- excessive sweating
- paranoia – extreme and unreasonable distrust of others
- psychosis – disordered thinking detached from reality
Larger psilocybin doses, including an overdose, can lead to intense hallucinogenic effects over a longer period of time. An intense “trip” episode may occur, which may involve panic, paranoia, psychosis, frightful visualizations (“bad trip”), and very rarely death. Memory of a “bad trip” can last a lifetime.
Abuse of psilocybin mushrooms could also lead to toxicity or death if a poisonous mushroom is incorrectly thought to be a “magic” mushroom and ingested. If vomiting, diarrhea, or stomach cramps begin several hours after consuming the mushrooms, the possibility of poisoning with toxic mushrooms should be considered, and emergency medical care should be sought immediately.
Tolerance to the use of psilocybin has been reported, which means a person needs an increasing larger dose to get the same hallucinogenic effect. “Flashbacks”, similar to those occur in some people after using LSD, have also been reported with mushrooms. It is reported that people who use LSD or mescaline can build a cross-tolerance to psilocybin, as well.