Repeated low doses of LSD were safe but did not improve mood or thinking in healthy adults
A 2022 controlled trial gave healthy adults repeated low doses of LSD — the kind people take when 'microdosing' — to test whether it actually changed their mood or thinking.
Many people who microdose say very low doses of LSD, taken every few days, lift their mood and sharpen their thinking. This study put that to a controlled test. Fifty-six healthy adults were split into three groups — a dummy-pill (placebo) group, a 13-microgram LSD group, and a 26-microgram LSD group — and took their assigned dose four times over about two weeks. Neither the participants nor the researchers scoring them knew who got real LSD. People on the higher dose could feel a mild drug effect, but it did not improve their mood or their performance on thinking and emotion tasks any more than the placebo. A drug-free check-in days later showed no lingering effects. The authors concluded the repeated low doses were safe but produced negligible changes in mood or cognition in these healthy volunteers.
In this randomized, double-blind, placebo-controlled dose-response study, 56 healthy adults aged 18-35 were assigned to placebo (N = 18), 13 μg LSD (N = 19), or 26 μg LSD (N = 19) and attended four 5-hour dosing sessions at 3-4 day intervals, followed by a drug-free follow-up session. The 26 μg dose produced modest subjective effects — increased ratings of 'feeling a drug effect' plus stimulant-like and LSD-like effects — but did not improve mood or performance on psychomotor or most emotional tasks relative to placebo. No residual effects on mood or task performance were detected at the drug-free follow-up. The authors conclude that, within a controlled setting and a limited number of administrations, the repeated low doses were safe but produced negligible changes in mood or cognition.
The authors flag several limitations. Participants were not highly emotionally distressed at enrollment, and the authors note that beneficial effects of low-dose LSD might emerge in more symptomatic individuals. The drug was administered only four times, with behavior measured while the drug was active at the receptor, so longer or alternative schedules were not tested. The mood and cognitive tasks were relatively simple standard measures that, the authors suggest, may not capture the effects users describe, and the study lacked pharmacokinetic (plasma-level) data for individual participants. Design-inherent points: the sample was small and drawn from a healthy, general-population cohort aged 18-35 — not a clinical or veteran group — limiting generalizability to people seeking symptom relief. The lead author disclosed advisory and board relationships with several pharmaceutical/biotech companies, none stated to be directly related to this study.
In a double-blind, placebo-controlled study, four repeated doses of LSD tartrate (13 or 26 μg) or placebo were administered to healthy adults at 3-4 day intervals, and the authors concluded that repeated low doses were safe but produced negligible changes in mood or cognition in healthy volunteers (de Wit et al., 2022, Addiction Biology).
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