A 2022 Review Mapped Microdosing Research—and Its Gaps

Written by Microdose News Editorial TeamNovember 8, 2026Research1 min read

Key takeaways

The review covered 44 studies through 2021.
Mixed designs and bias limit conclusions.
Research synthesis is not proof of treatment efficacy.

A systematic review covering research from 1955 through 2021 brought together 44 studies of low-dose psychedelics. Its value lies as much in the methodological gaps it identified as in the signals it summarized.

Different evidence under one umbrella

Polito and Liknaitzky published the review in Neuroscience & Biobehavioral Reviews in May 2022. The included literature spanned different eras, substances, measures, and study designs.

Laboratory experiments and self-report investigations do not carry the same causal strength. A review needs to preserve those differences rather than treating every positive observation as equally convincing.

Why study quality matters

The review identified substantial variation in design and risk of bias. Participants’ expectations, selection into studies, inconsistent definitions, and limited control conditions can shape the apparent pattern of findings.

Bringing papers together does not remove their original limitations. The number of studies is not a substitute for consistent, rigorous evidence.

What a review cannot decide

The review summarized reported signals and recommendations for future work; it did not establish microdosing as a treatment. Mixed evidence should not be turned into a promise of benefit for a particular patient.

A review through 2021 also has a defined evidence window. Later studies need to be considered separately rather than implied to be included in the original synthesis.

A roadmap for stronger research

Better standardized interventions, masking checks, meaningful outcomes, adequate samples, and longer monitoring would improve the field. Clear reporting of harms is as important as reporting favorable outcomes.

Read our introduction to the evidence for a practical way to keep uncertainty visible when evaluating claims.

Sources and further reading

Explore our research resources for help checking original sources.

Medical information: This article is for education, not diagnosis or treatment. Discuss health decisions with a qualified clinician. Do not change prescribed treatment based on this article.

The accompanying picture is an illustrative editorial image, not a photograph of the cited study or its participants.