Anxiety DisordersNeurocognitive DisordersHealthy VolunteersMicrodosingSafety & Risk ManagementLSDPsilocybin

Side Effects of Microdosing Lysergic Acid Diethylamide and Psilocybin: A Systematic Review of Potential Physiological and Psychiatric Outcomes

This systematic review (s=31) examines the side effects of microdosing LSD and psilocybin, finding that adverse effects are typically dose-dependent, mild, and short-lived. Common side effects include increased blood pressure, anxiety, and cognitive impairment. The review highlights the lack of standardised reporting on side effects and calls for future studies to provide more systematic and transparent assessments.

Authors

  • Modzelewski, S.
  • Waszkiewicz, N.
  • Lukasiewicz, K.

Published

Neuropharmacology
meta Study

Abstract

Objective

Psychedelics are gaining renewed attention, especially through the practice of microdosing, where low doses are taken regularly. Microdosing lysergic acid diethylamide (LSD) and psilocybin is used by both healthy individuals and those with mental health conditions to improve daily functioning, reduce anxiety, and enhance mood and cognition. However, there is limited information about the side effects of this practice. This review aimed to collect and characterize the side effects of psychedelic microdosing.

Methods

We conducted a systematic review of original papers from PubMed, Web of Science, and Scopus (accessed August 03, 2024) that reported side effects of microdosing LSD and psilocybin. Non-English papers, non-original studies, studies without typical microdosing doses, or those lacking descriptions of side effects were excluded. Our methodology has been developed in accordance with PRISMA guidelines. Because side effects were assessed heterogeneously in these papers, we did not perform a bias evaluation.

Results

We included 31 studies, 15 of which we classified as laboratory studies with higher quality evidence, and 14 studies with lower quality evidence, as well as 2 clinical cases. Side effects were typically dose-dependent, mild, and short-lived. Common adverse effects included increased blood pressure, anxiety, and cognitive impairment.

Discussion

This review is limited by the heterogeneity in reporting side effects and the short duration of many studies. Future studies should transparently and systematically present a description of side effects.

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Research Summary of 'Side Effects of Microdosing Lysergic Acid Diethylamide and Psilocybin: A Systematic Review of Potential Physiological and Psychiatric Outcomes'

Introduction

Research on classic psychedelics has resurged since regulatory restrictions of the late 20th century, and with that has come widespread interest in the practice of microdosing — the repeated administration of sub‑perceptual doses of substances such as LSD and psilocybin. Earlier studies, largely observational or short-term laboratory experiments, report many anecdotal benefits (improved mood, cognition and daily functioning) but provide limited, inconsistent and often non-systematic information on adverse effects. The literature is further complicated by heterogeneous definitions of microdosing, variable preparation methods, and reliance on internet surveys and self-report data. Modzelewski and colleagues set out to systematically collect and characterise reported physiological and psychiatric side effects of microdosing with LSD and psilocybin. The review aimed to describe the nature, frequency, severity and course of adverse events in the existing literature, separating physiological and psychiatric outcomes and highlighting gaps that impede understanding of long‑term risk.

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Study Details

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