Microdosing Research Review: What Science Actually Shows

What microdosing means

Microdosing means taking a small dose of a psychedelic, usually LSD or psilocybin mushrooms, repeatedly on a schedule, with the aim of feeling better or working better without a full psychedelic experience. A study team at Imperial College London described it as taking about 10% of a recreational dose two or three times a week. (eLife, 2021) Another research group noted that users commonly take low doses of LSD at 3 to 4 day intervals. (Addiction Biology, 2022)

There is no agreed definition. A 2022 systematic review of 44 studies found definitional inconsistencies across the literature and proposed suggested dose ranges for each substance. (Neuroscience & Biobehavioral Reviews, 2022) That matters when reading studies: one trial's "microdose" can be another's low dose, and strength varies between mushroom batches in a way it does not for a measured LSD solution.

This page has no condition page to point to, because microdosing is not an established treatment for any condition. For full-dose psilocybin therapy, see psilocybin for depression; for how to read psychedelic trials in general, see psilocybin clinical trial results.

What surveys and observational studies found

Most early evidence came from people who already microdosed. In one study of 98 microdosers tracked over six weeks, people rated their functioning higher on dosing days, and reported less depression and stress over time, but more neuroticism. In a second survey, people expected larger and broader benefits than actual microdosers reported. (PLOS ONE, 2019)

A smartphone-app study compared 4,050 microdosers with 4,653 non-microdosers. Psilocybin was the substance used by 85% of microdosers, health and wellness were the main motives, and among people with mental health concerns, microdosers reported lower depression, anxiety and stress. (Scientific Reports, 2021) A follow-up tracking 953 psilocybin microdosers and 180 comparators for about 30 days found small to medium improvements in mood and mental health. (Scientific Reports, 2022)

These studies are useful for describing who microdoses and why, but they cannot separate the drug from expectation. Participants choose to microdose, know what they are taking and usually expect it to help. See the research library for each study's design.

Placebo-controlled trials

When researchers supply the drug and nobody knows who got what, the picture changes.

• LSD in the lab. At the University of Chicago, 56 healthy adults took 13 or 26 micrograms of LSD or placebo four times at 3 to 4 day intervals. The higher dose produced modest drug effects but did not improve mood or task performance, and nothing carried over to a drug-free session afterwards. (Addiction Biology, 2022) An earlier single-dose study from the same group found effects on vigour at 26 micrograms but no change in most mood, cognitive or physiological measures. (Biological Psychiatry, 2019)
• LSD at home. In New Zealand, 80 healthy men took 10 micrograms of LSD or placebo every 3 days for 6 weeks, mostly at home. Dose days brought higher ratings of creativity, energy, happiness and wellness than non-dose days, but no questionnaire or cognitive test changed between the start and the end of the 6 weeks. (Biological Psychiatry, 2023)
• Psilocybin mushrooms. In Argentina, 34 people starting to microdose took 0.5 g of dried mushrooms or placebo. The acute effects were stronger than placebo only in people who correctly guessed their condition, and there was no sign of better well-being, creativity or cognition. (Translational Psychiatry, 2022) A Dutch crossover study found psilocybin microdosing did not change emotion processing or symptoms of anxiety and depression compared with placebo. (Journal of Psychopharmacology, 2022) Two further double-blind truffle trials, published in 2025, found no significant effect on cognitive or subjective measures after correction for multiple comparisons, with participants staying blinded throughout. (Neuropharmacology, 2026 (online October 2025))

A 2024 review of 14 rigorously controlled studies, all of LSD at 5 to 20 micrograms, concluded that acute microdoses altered blood pressure, sleep, mood and perception, but that repeated doses did not alter mood or cognition on any measure studied. (Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, 2024)

Self-blinding and the expectancy problem

Imperial College's self-blinding study let people who were already planning to microdose build their own placebo control at home, using instructions to mix capsules so they did not know which they were taking. 191 people completed it. All psychological outcomes improved over the 4-week dosing period, but the placebo group improved too, and there was no significant difference between groups. The small acute differences that did appear could be explained by people breaking blind. (eLife, 2021) A later reanalysis by the same authors argued that weak blinding combined with positive expectations can inflate effects and create false positive findings, and that microdosing can be understood as an active placebo. (Scientific Reports, 2023)

Blind-breaking turns up in the lab trials too. In the Dutch crossover study, participants broke blind in the second block, and in the Argentine mushroom study the stronger acute effects appeared only in people who guessed correctly. (Journal of Psychopharmacology, 2022; Translational Psychiatry, 2022) The New Zealand team concluded that future microdosing trials in patients will need active placebos, which produce a noticeable effect of their own, to control for this. (Biological Psychiatry, 2023)

Not every researcher agrees that expectation explains everything. The authors of the 2022 systematic review argued that claims that microdosing effects are largely due to expectancy are premature and possibly wrong. (Neuroscience & Biobehavioral Reviews, 2022) The fair summary is that the controlled studies so far have not shown a lasting benefit over placebo in healthy volunteers, and that patients with depression, the group most likely to try it, have barely been studied.

What is known about safety

In short controlled studies, low doses looked tolerable. The 2024 review found no serious adverse effects across its 14 LSD studies. (Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, 2024) A phase 1 trial in 48 healthy older adults found adverse events no more frequent than with placebo and no impairment of cognition or balance at 5 to 20 micrograms every fourth day. (Psychopharmacology, 2020) Anxiety is the clearest reported risk: in the New Zealand home-dosing trial, treatment-related anxiety led 4 people in the LSD group to withdraw. (Biological Psychiatry, 2023)

The open question is the heart. Valvular heart disease has been proposed as a potential risk of chronic microdosing because these drugs activate the serotonin 5-HT2B receptor. A 2023 review found that LSD, psilocybin, DMT and MDMA all bind the 5-HT2B receptor and act as partial agonists, that safety margins at typical microdoses were wider than for known valve-damaging drugs but not without potential risk, that no animal or clinical study had been designed to evaluate the risk for the psychedelics, and that chronic full-dose MDMA has some clinical evidence linking it to valve disease. (Journal of Psychopharmacology, 2023) A 2025 open-label trial of 19 people with depression who microdosed LSD for 8 weeks observed no serious adverse events and no clinical changes in safety measures that included echocardiography, and described itself as the first study to look for valvulopathy after repeated psychedelic doses in humans. (Neuropharmacology, 2026 (online November 2025)) Eight weeks in 19 people cannot rule out a risk from years of use.

The general psilocybin cautions still apply at low doses. Reports of lithium taken with a classic psychedelic often involved seizures. (Pharmacopsychiatry, 2021; Oregon Health Authority, Public Health Division, 2026) SSRIs and SNRIs can blunt psilocybin's effects. (Journal of Psychopharmacology, 2023; Neuropsychopharmacology, 1996; Psychopharmacology (Berl), 2022) People with a personal or family history of psychosis are excluded from research. (Journal of Psychopharmacology, 2008; Oregon Health Authority, Public Health Division, 2026) Do not stop or change a prescribed medicine to microdose; talk to your prescriber, and use the interaction checker. For general harm reduction, see harm reduction basics and the safety hub.

The law

Dose size does not change legal status. LSD and psilocybin are both listed in Schedule I of the US Controlled Substances Act. (Legal Information Institute (Cornell), current) Oregon's licensed programme allows psilocybin only at a licensed service centre under a facilitator, with no take-home or retail sale, so a home microdosing routine is outside it. (Oregon State Legislature, current edition) In the UK, fungus containing psilocin is a Class A drug. (legislation.gov.uk, current text; Home Office (GOV.UK), current page) Health Canada says the production, sale and possession of magic mushrooms are illegal. (Health Canada, 8 Oct 2025) The Netherlands is the main exception people cite: fresh psilocybin truffles fall outside the Opium Act, although mushrooms have been on its List II since 2008. (Overheid.nl Officiele bekendmakingen, 28 Dec 2011; Overheid.nl Officiele bekendmakingen, 17 Nov 2008) Check a specific place with is it legal.

What would settle it

The research that matters most is in people with a diagnosis, over months, with an active placebo. One such trial, LSDDEP2 in New Zealand, was registered in 2024: 8 weeks of LSD microdoses at home against an active placebo in patients with major depressive disorder, with depression scores as the main outcome. (Trials, 2024) Its open-label pilot reported a 59.5% fall in depression scores, but with 19 participants and no control group, that is a reason to run the controlled trial, not a result. (Neuropharmacology, 2026 (online November 2025)) Recruiting psychedelic studies are listed on the clinical trials page.