Is Microdosing a Placebo?

This review (2023) critically assesses the available evidence from dose-controlled studies investigating low doses of LSD and psilocybin. It proposes eight potential issues, such as small sample sizes, a limited number of controlled studies, and the possibility of selection bias, that challenge the claims that microdosing is predominantly a placebo effect. It suggests that it is currently inconclusive whether microdosing is merely a placebo.

Abstract of Is Microdosing a Placebo?

“Some recent research and commentary have suggested that most or all the effects reported by people who microdose psychedelics may be explained by expectations or placebo effects. Here we step through all the available evidence from dose-controlled studies that have investigated the effects of low doses of LSD and psilocybin. We suggest eight reasons why current claims that microdosing is predominately a placebo are premature and possibly wrong: 1) there have been only a small number of controlled studies; 2) studies have had small sample sizes; 3) there is evidence of dose-dependent effects; 4) studies have only investigated the effects of a small number of doses; 5) the doses investigated may have been too small; 6) studies have looked only at non-clinical populations; 7) studies so far have been susceptible to selection bias; and 8) the measured impact of expectancy is small. Considering the available evidence, we conclude that it is not yet possible to determine whether microdosing is a placebo.”

Authors: Vince Polito & Paul Liknaitzky

Summary of Is Microdosing a Placebo?

Microdosing became popular around 2015, with thousands experimenting with this novel way of using psychedelics. There is still little scientific knowledge about the effects, mechanisms, or risks of regular use of psychedelic drugs at low doses.

Early microdosing studies reported positive effects on mental health, well-being, cognition, personality, changes in conscious state, and physiological changes.

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