The effects of psilocybin mushrooms come from psilocybin and psilocin. When psilocybin is ingested, it is broken down to produce psilocin, which is responsible for the psychedelic effects. Psilocybin and psilocin create short-term increases intolerance of users, thus making it difficult to abuse them because the more often they are taken within a short period of time, the weaker the resultant effects are. Psilocybin mushrooms have not been known to cause physical or psychological dependence (addiction). Using psilocybin is often associated with having negative physical and psychological consequences. The physical effects, tend to appear around 20 minutes of ingesting and will last approximately 6 hours. The effects include nausea, vomiting, muscle weakness, drowsiness, and lack of coordination, although many of the sickness associated side effects may be attributed to mould and or mildew which often accompanies the drug when purchased through black market means and not grown in sterile or cleanly growing environments. Mis-handling and improper storage thereof may also attribute to lower performing accounts of psilocybin and psilocin in the mushrooms resulting in larger required doses, which can often be accounted for the user’s non-psychological effects that are considered negative. Nevertheless, no evidence has been shown that users will become physically dependent on psilocybin, however, tolerance for the drug may develop when it is ingested in a short period of time.
As with many psychedelic substances, the effects of psychedelic mushrooms are subjective and can vary considerably among individual users. The mind-altering effects of psilocybin-containing mushrooms typically last from three to eight hours depending on dosage, preparation method, and personal metabolism. The first 3–4 hours of the trip are typically referred to as the ‘peak’ in which the user experiences more vivid visuals and distortions in reality. However, the effects can seem to last much longer to the user because of psilocybin’s ability to alter time perception.
In internet surveys, some psilocybin users have reported symptoms of hallucinogen persisting perception disorder, although this is uncommon and a causal connection with psilocybin use is unclear. There is a case report of perceptual disturbances and panic disorder beginning after using psilocybin mushrooms in frequent cannabis users with a pre-existing history of derealization and anxiety.
Noticeable changes to the auditory, visual, and tactile senses may become apparent around 30 minutes to an hour after ingestion, although effects may take up to two hours to take place. These shifts in perception visually include enhancement and contrasting of colours, strange light phenomena (such as auras or “halos” around light sources), increased visual acuity, surfaces that seem to ripple, shimmer, or breathe; complex open and closed eye visuals of form constants or images, objects that warp, morph, or change solid colours; a sense of melting into the environment, and trails behind moving objects. Sounds seem to be heard with increased clarity; music, for example, can often take on a profound sense of cadence and depth. Some users experience synesthesia, wherein they perceive, for example, a visualization of colour upon hearing a particular sound.
As with other psychedelics such as LSD, the experience, or “trip”, is strongly dependent upon set and setting. A negative environment could contribute to a bad trip, whereas a comfortable and familiar environment would set the stage for a pleasant experience. Psychedelics make experiences more intense, so if a person enters a trip in an anxious state of mind, they will likely experience heightened anxiety on their trip. Many users find it preferable to ingest the mushrooms with friends, people with whom they are familiar, or people who are familiar with ‘tripping’. Use of psilocybin is associated with negative physical and psychological consequences. The physical effects, which appear within 20 minutes of ingestion and last approximately 6 hours, include nausea, vomiting, muscle weakness, drowsiness, and lack of coordination. While there is no evidence that users may become physically dependent on psilocybin, tolerance for the drug does develop when it is ingested continuously over a short period of time. The psychological consequences of psilocybin use include hallucinations and an inability to discern fantasy from reality. Panic reactions and psychosis also may occur, particularly if a user ingests a large dose. In addition to the risks associated with ingestion of psilocybin, individuals who seek to use psilocybin mushrooms also risk poisoning if one of the many varieties of poisonous mushrooms is incorrectly identified as a psilocybin mushroom.
The dosage of mushrooms containing psilocybin depends on the potency of the mushroom (the total psilocybin and psilocin content of the mushrooms), which varies significantly both between species and within the same species, but is typically around 0.5–2.0% of the dried weight of the mushroom. A typical dose of the common species Psilocybe cubensis is about 1.0 to 2.5 g, while about 2.5 to 5.0 g dried mushroom material is considered a strong dose. Above 5 g is often considered a heavy dose with 5.0 grams of dried mushroom often being referred to as a “heroic dose”.
The concentration of active psilocybin mushroom compounds varies not only from species to species but also from mushroom to mushroom inside a given species, subspecies or variety. The same holds true even for different parts of the same mushroom. In the species, Psilocybe samuiensis, the dried cap of the mushroom contains the most psilocybin at about 0.23%–0.90%. The mycelium contains about 0.24%–0.32%.
Psilocybin mushrooms are regulated or prohibited in many countries, often carrying severe legal penalties (for example, the US Psychotropic Substances Act, the UK Misuse of Drugs Act 1971 and Drugs Act 2005, and in Canada the Controlled Drugs and Substances Act).