Psilocybin is one of the hallucinogenic drugs contained in certain types of mushrooms – hence the name “magic mushrooms.” These mushrooms can be purchased in fresh or dried forms that can be made into tea or added to cooked foods, or even in powders that can be injected, smoked or snorted. Psilocybin can even appear in capsules, although many of them are laced with other drugs like LSD or PCP. 
Users should be cautious with fresh mushrooms, though, as some that look remarkably like psilocybin mushrooms are actually poisonous and could possibly cause liver damage or even death. 
+ WHAT IS THE HISTORY OF PSILOCYBIN MUSHROOMS?
Archaeological evidence suggests that hallucinogenic mushrooms have been used by humans for thousands of years. Some evidence from the Sahara desert dates back at least 7,000 years. And there are extensive accounts of Mayan and Aztec cultures using these types of mushrooms in what is now Mexico and Guatemala dating back to the 15th and 16th centuries. 
Psilocybin was first isolated from a mushroom in a laboratory in 1957, by Swiss chemist Albert Hoffman. The following year, psilocybin was produced synthetically for the first time. 
Also in 1957, Gordon Wasson, a former vice-president at investment banking company J.P. Morgan & Co., had a photo essay published in Time magazine detailing a voyage to Oaxaca, Mexico, to meet an indigenous mushroom shaman there. This essay is credited with sparking the popularity of psilocybin mushrooms in Western culture. 
+ WHAT ARE THE EFFECTS OF PSILOCYBIN MUSHROOMS?
The effects of psilocybin vary greatly depending on the size of the dose, the age and weight of the user, past drug use, and even what you’ve had to eat around the time of ingestion. The effects can usually be felt within about 30 minutes, and can last anywhere from three to six hours. 
For some users, psilocybin affects how they see, smell, hear, taste and touch – they believe they can see music or hear colours, for example. Their perceptions of their bodies can change, feeling as though they are exceptionally light or heavy. Physical effects of psilocybin include:
- high blood pressure;
- rapid heart rate;
- dizziness or lightheadedness;
- shivers and chills;
- upset stomach or nausea; and
- numbness in the mouth and tongue. 
Some users may also experience negative effects with psilocybin use, which is commonly referred to as a “bad trip.” These negative effects may include: unpleasant or intense hallucinations; anxiety; paranoia; and panic or fear.  After ingesting mushrooms, uers may also experience headaches for up to two days afterwards, along with exhaustion, depression and anxiety. 
+ CAN YOU DEVELOP A TOLERANCE TO PSILOCYBIN?
If you use psilocybin mushrooms every day, you can build up a tolerance in as few as three or four days. This means you would need take increasing amounts of the drug in order to achieve the same high as earlier. After several days, it is possible to build up a “complete tolerance,” meaning the drug will have no effect on you, no matter how much of it you take.  However, discontinuing use for about a week usually returns people to their normal tolerance level.