Psilocybin

The active compound in “magic mushrooms”

Psilocybin is a naturally occurring psychedelic compound made by certain mushrooms. In the body it is converted to psilocin, which acts mainly on serotonin 2A receptors and alters perception, mood and the sense of self for roughly six hours. It is a chemical substance and an investigational medicine, not a diagnosis or a type of therapy.

Where it comes from

Indigenous peoples in Mexico and Central America have used these mushrooms in ceremonies for centuries. A 1957 article in Life magazine by R. Gordon Wasson brought them to wide Western attention, and in 1958 the Swiss chemist Albert Hofmann isolated psilocybin and psilocin from the species Psilocybe mexicana. Brain imaging later showed that the intensity of the experience rises with the share of serotonin 2A receptors that psilocin occupies.

What trials show

Most of the evidence concerns depression. In a phase 2 trial of 233 adults with treatment-resistant depression, one 25 mg dose given with psychological support lowered scores on a 60-point depression scale by 6.6 points more than a 1 mg control dose after three weeks. Sustained response at 12 weeks did not clearly support that result, 77 percent of participants reported side effects such as headache and nausea, and suicidal thoughts or self-harm occurred in every dose group. In 104 adults with major depression, one dose outperformed a niacin placebo by 12.3 points on the same scale after six weeks, with no serious adverse events. A 59-person comparison found no significant difference from the antidepressant escitalopram on its main measure.

A 2024 meta-analysis found larger effects when symptoms were self-reported and when participants had used psychedelics before, a sign that expectations play a part. None of these trials shows that psilocybin treats burnout or a sense of emptiness after success.

Legal status in October 2026

Psilocybin is a Schedule I drug under US federal law, and the FDA has not approved any psilocybin product. In April 2026 the FDA granted a rolling review of COMP360, a synthetic formulation from Compass Pathways, which expects to complete its application in the fourth quarter of 2026. In Australia, psychiatrists approved as a TGA Authorised Prescriber have been able to prescribe it for treatment-resistant depression since July 1, 2023. Oregon and Colorado license supervised psilocybin services for adults, delivered by state-licensed facilitators; in Oregon no prescription or referral is needed. Our country-by-country reference explains each mechanism, including the one in Jamaica, where our residencies take place. Our safety and screening page covers who should not take it.