Other Drugs

Psilocybin (Mushrooms)

What is psilocybin?

Psilocybin and psilocin are chemical compounds obtained from certain types of dried or fresh hallucinogenic mushrooms found in Mexico, Central America and the United States. These compounds have similar structure to lysergic acid diethylamide (LSD).

There are over 180 species of mushrooms that contain the chemicals psilocybin or psilocin. Like the peyote, hallucinogenic mushrooms have been used in native rites for centuries. Both psilocybin and psilocin can also be produced synthetically in the lab.

How is psilocybin used?

Usually taken orally, psilocybin is found in dried or fresh mushrooms or as a powder in capsules. It is also sometimes brewed into a tea. Typical doses range from 10 to 50 milligrams (approximately 20 to 30 grams of fresh mushrooms or 1 to 2.5 grams of dried mushroom powder) and the effects usually take 1 to 2 hours to start and typically last for about 6 hours. However, dosages may vary because psilocybin concentrations differ widely according to the genus, strength, and condition (fresh or dried) of the mushrooms.

Why do people use psilocybin?

Mushrooms have been taken in religious rituals in indigenous cultures in Mexico and Central America for thousands of years. Today, recreational users take them to induce mild euphoria, tingling physical sensations, increased sensitivity to music, and visual sensations. They are considered by many to be a more gentle or natural hallucinogen in comparison to other, more aggressive chemical hallucinogens such as Ketamine and LSD.

What are the short-term effects or risks of using psilocybin?

Misidentification is one of the biggest dangers that can occur with taking psilocybin mushrooms. It is difficult to know if the mushrooms are psilocybin mushrooms because poisonous mushrooms also cause hallucinogenic effects. Signs that the mushrooms are toxic include stomach pains, vomiting and diarrhea. Poisonous mushrooms can even lead to death.

It is also difficult to determine what genus of mushroom you have and the dose of active hallucinogen each mushroom contains. To reduce the risk of a dangerous experience, it is safer to take a small amount and wait for its effects to be felt. In some cases, hallucinating can be unpleasant or even terrifying and the memory of this intense fear can remain with the person for life. A bad trip can occur at any dose. Signs of a bad trip include anxiety, confused or disordered thinking and panic.

At doses of 13 mg or more, users' perceptions become altered, and they develop the same symptoms as an LSD user. They also might experience facial flushing, sweating, a slowed sense of time, and the sense that they are separate from their bodies. At these higher doses some of the warning signs of a potential overdose include:

  • Lightheadedness or dizziness

  • Numbness of the tongue, lips, or mouth

  • Shivering or sweating

  • Nausea

  • Anxiety

Remember never to drive on psilocybin or any other hallucinogen. Operating machinery while under the influence of reality-altering substances is extremely dangerous. 

Are there long-term consequences to using psilocybin?

A "bad trip" may contain terrifying thoughts, feelings, and fears. Also, psilocybin can cause flashbacks, in which the person suddenly relives certain aspects of the experience without having taken the drug. Flashbacks may occur a few days or more than a year after use of psilocybin.

In addition, serious psychiatric conditions can develop after even one use of psilocybin. The cause of these effects is not known. These conditions include:

  • Drug-induced psychosis. Psychosis is a serious condition in which the person has lost the ability to recognize reality, think rationally, or communicate with others. The person may have dramatic mood swings, ranging from being extremely overactive (mania) to severe depression. Psychosis from psilocybin may last for years.
  • Hallucinogen-persisting perception disorder (HPPD). With HPPD, the person has flashbacks in which the person experiences recurrences of some of the sensory distortions that occurred while under the influence of the drug. The person may have the same flashback for years after stopping use of psilocybin. 

Is psilocybin addictive?

Psilocybin is not considered an addictive drug. Although addiction to hallucinogens is rare, poly-drug addicts (people who are addicted to several drugs) frequently abuse hallucinogens. However, psilocybin does produce tolerance, so some users who take the drug repeatedly must take higher doses to achieve the same effects. This is very dangerous given the unpredictability of the drug and dose. Cross-tolerance between psilocybin and other hallucinogens has been reported. 

Is psilocybin illegal?

Yes, Psilocybin is illegal and it is currently a Schedule I drug (drug with no currently accepted medical use and a high potential for abuse). Its possession, use, and sale carry heavy prison sentences and fines, as well as disciplinary consequences at Brown. See the Brown University Policy on Drugs on the Student Rights and Responsibilities web site. 

How do I help a friend who's having a bad trip?

It is important to make your friend feel safe and comfortable. Speak to them in a soothing voice and tone and reassure them that their emotions, sensations, and visions are just the effects of the drug and will wear off in time. Additionally, it would be helpful to keep them away from other people they do not know, visual stimulation, and loud or abrupt noises. If your friend is inconsolable or seems violently agitated, then seek medical help right away. Call EMS at 401.863-4111.

How do I help a friend who's having trouble with drugs or alcohol?

If you are concerned about a friend's drug or alcohol use, this page contains information about different ways to help them. 

Related Links

Dance Safe  
Dance Safe is a harm-reduction web site centered on drugs found in nightclubs and raves. The site offers drug information, a risk assessment, ecstasy testing kits and e-news.

The Good Drugs Guide  
This British harm-reduction web site provides extensive information on mushrooms, including the basics, dangers, mixing with other drugs and links.

National Institute of Drug Abuse   
NIDA's report on hallucinogens and dissociative drugs is available from this link. NIDA drug pages have research reports, statistics and information on addiction.


If you or a friend are having trouble with drugs or alcohol, or just have questions, there is help available.

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