Review of microdosing trials finds no clear mood benefit over placebo in healthy adults

The question

Does taking very small, non-hallucinogenic doses of psychedelics (“microdosing”) improve mood, cognition or wellbeing in healthy adults, and is it safe?

What they did

Researchers searched three research databases up to February 2026 for studies of repeated sub-hallucinogenic psychedelic doses in healthy, non-clinical adults. They included randomized trials, non-randomized prospective studies, cross-sectional surveys and longitudinal observational studies, and analyzed them separately by design. In total, 24 studies with 3,681 participants met the criteria, and 6 studies contributed to the pooled statistical analyses.

What they found

Randomized trials of psilocybin and LSD microdosing produced noticeable subjective and brain-activity effects but little change in cognition, creativity or lasting mood. Pooled randomized data (two parallel trials, 3 comparisons, 117 people) showed no clear reduction in depressive symptoms (standardized mean difference -0.19; 95% confidence interval -0.56 to 0.19), anxiety (-0.20; -1.11 to 0.71) or stress (0.02; -0.39 to 0.43) — all ranges cross zero, meaning no reliable effect. Non-randomized studies (1,013 people) suggested small improvements in depressive symptoms and anxiety, but the estimates were imprecise and inconsistent. Side-effect rates, pooled from two trials (4 comparisons, 109 people), were similar between microdosing and control.

The fine print

Only 6 of 24 studies could be pooled, and the randomized evidence rests on roughly 117 participants — far too few to settle the question. Observational and survey studies were self-selected and unblinded, so expectancy (placebo-like belief effects) and lifestyle differences could explain their more positive results. Anxiety findings varied widely between studies, follow-up was short, and this summary is based on the abstract only.

What it means

At present, the controlled evidence does not show that microdosing psychedelics reliably improves mood, anxiety or stress in healthy adults beyond placebo, though it did not appear to raise side-effect rates in the small trials analyzed.

Evidence grade: Moderate. A systematic review and meta-analysis, but it pools very different study designs and only a small number of randomized participants contributed to the key comparisons.

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