Review of psilocybin microdosing studies finds low-certainty evidence for benefits

The question

What does the existing research actually show about people taking very small, repeated doses of psilocybin mushrooms or truffles — the practice known as microdosing?

What they did

Researchers searched the published literature for studies of adults who microdosed psilocybin mushrooms or truffles. They followed a standard review method (PRISMA), registered the plan in advance, and assessed each study for risk of bias. Eleven articles met the criteria — five quantitative and six qualitative — covering 3,262 adults in the United States (4 studies), the Netherlands, Argentina, international samples (2 each) and Slovenia (1).

What they found

Some studies reported that microdosing was linked to improvements in well-being, mental health, thinking, physical health, creativity, relationships, pain, curiosity, substance dependence and the senses. But most of the evidence had at least some risk-of-bias concerns or was qualitative, using a mix of self-reported measures. About 86% of people’s stated reasons for microdosing were non-medical and only 14% related to a medical diagnosis, mostly mental health. Dosing schedules and preparations varied widely. Most studies did not report adverse events; those reported were mostly mild. Four studies declared conflicts of interest and four did not disclose their funding.

The fine print

None of the included studies were randomized controlled trials, so benefits cannot be attributed to the microdosing itself — expectation and self-selection could explain the reported effects. Outcomes were self-reported and inconsistent across studies, doses and products were not standardized, and most studies did not systematically record side effects, which means the safety picture is incomplete. This summary is based on the abstract only.

What it means

Enthusiasm for psilocybin microdosing currently outpaces the evidence: the reported benefits come mostly from people describing their own experiences, not from controlled trials that can separate the drug from expectation.

Evidence grade: Low. A systematic review, but the studies it pooled were mostly observational or qualitative with self-reported outcomes and risk-of-bias concerns, so no cause-and-effect conclusions are possible.

This summary is based on the study’s published abstract.