Psilocybin has a low level of toxicity, which means that it has a low potential of causing potentially fatal events like breathing problems or a heart attack.1 However, studies show there are health risks associated with taking psilocybin, particularly when unsupervised and outside of a research study and clinical supervision. These include:
Dangerous Behavior
People may do things that put themselves or others at risk of physical harm after taking mushrooms in an unsupervised environment—driving dangerously or walking in traffic, for example—as they may be less aware of their physical surroundings13 and have an impairment in their ability to think clearly.
Physical Side Effects
Psilocybin typically raises blood pressure and heart rate, which may be dangerous for people with heart conditions. People may also experience side effects like agitation, confusion, vomiting or nausea, which may be severe and require medical attention.14 With more public interest and, in some areas, fewer legal restrictions on psilocybin use, exposures reported to poison control centers have increased over the past few years.15
There is also the risk of misidentifying mushrooms and taking a toxic mushroom instead of one containing psilocybin.16 According to the U.S. Centers for Disease Controls and Prevention (CDC), some commercial products such as candies marketed as containing psilocybin have also been found to contain toxic chemicals and have caused severe illness.
Fear
Some people who take psilocybin have extreme fear, anxiety, panic, or paranoia as they experience its hallucinogenic effects, which is known as a “bad trip.”17
Mental Health Issues
The risk of mental health problems such as psychosis or suicidality in supervised clinical settings among people who participate in research on psilocybin is low. However, poor mental health outcomes may be more likely with use outside of clinical settings. For more information, see “What is the relationship between psychedelic and dissociative drugs and mental illness?”