Where the term comes from

The pairing is credited to Timothy Leary, who ran psilocybin research at Harvard in the early 1960s. In a 1964 book written with Ralph Metzner and Richard Alpert, he described set as a person’s preparation, personality and mood at the time, and setting as physical, social and cultural. The book claimed that the nature of the experience depends almost entirely on the two, a claim later research has qualified. The idea is older than the name: a history of the concept traces it through 1950s drug research and the methods of early psychedelic therapists. Norman Zinberg later applied it to drug use in general in his 1984 book Drug, Set, and Setting.

What the research shows

Dose matters most, but it is not the whole story. In pooled data from 23 studies with 409 psilocybin sessions in 261 healthy volunteers, people high in the trait of absorption, a tendency to become deeply immersed, tended to have pleasant and mystical-type experiences, while younger age, an emotionally excitable temperament and a session involving a PET brain scan predicted anxious ones.

In a prospective survey of 654 people planning to take a psychedelic, clear intentions went with more mystical-type experiences, and a positive mindset with fewer challenging ones. Still, a 2022 review of 43 studies found broad agreement that setting matters but few consistent, rigorous tests of which parts of it do.

In clinical practice

Johns Hopkins safety guidelines describe a session room that looks like a living room rather than a clinic, eyeshades and headphones with music, careful preparation, and at least two monitors present throughout. Setting therefore covers who is in the room as much as what the room looks like. Whether a more comfortable or luxurious setting improves outcomes has not been rigorously tested. Our own sessions are one-to-one at a private site, with two facilitators present for the whole session. For questions to ask any provider about the people and the room, see our guide to choosing a psychedelic retreat.

Related terms

Psychedelic Integration: the work after the session.

Psilocybin Contraindications: medical screening, a separate safeguard.

Serotonin Syndrome: what is known about psilocybin with antidepressants.