Microdosing psilocybin in Seattle: what the research says

What microdosing is

Microdosing means taking a small fraction of a psychedelic dose, on purpose too small to cause a trip, usually on a repeating schedule with rest days in between. People who do it describe the goal as feeling like a slightly better version of an ordinary day rather than feeling altered.

That makes microdosing different from the psilocybin therapy being tested in clinical trials, which uses a full dose taken once or twice under supervision. The two get lumped together in headlines, but the evidence for one doesn't carry over to the other.

We don't publish amounts or schedules. Potency varies a lot from one mushroom to the next and even between the cap and stem of the same mushroom, and the right amount depends on the person and their medications. Harm-reduction organizations on our resources page are a better place for that conversation, and so is a doctor if you take any medication.

Why people try it

In the largest survey of people who microdose, health and wellness were the most common motives, and microdosers were more likely than non-users to report a history of mental health concerns (Rootman et al., 2021). Others try it for focus or creativity. Those are serious reasons, and they're exactly why the quality of the evidence matters.

What the research shows

There are two kinds of evidence on microdosing, and they point in different directions.

Surveys of people who microdose

A 2021 study in Scientific Reports compared 4,050 people who microdose psychedelics, most of them with psilocybin, with 4,653 who don't. Among people with mental health concerns, the microdosers reported lower depression, anxiety and stress (Rootman et al.). A follow-up tracked 953 microdosers and 180 non-users over about a month and found small-to-medium improvements in mood (Rootman et al., 2022). These studies are large, but they can't separate the effect of psilocybin from the effect of expecting it to help, and people who had a bad experience are less likely to keep microdosing and answer the survey.

Placebo-controlled studies

When researchers hide whether people got psilocybin or a placebo, the picture changes:

• Self-blinding study, 2021. 191 people made their own blinded capsules, some with their microdose and some empty. Most were microdosing LSD; about a quarter used psilocybin mushrooms. Both groups improved on well-being and mood, with no meaningful difference between them; the few small differences tracked whether people guessed correctly what they'd taken (Szigeti et al., eLife).
• Mushroom microdosing trial, 2022. 34 people took dried mushroom or placebo under double-blind conditions. Brain activity measured by EEG changed, and people who correctly guessed they'd had psilocybin felt stronger effects, but well-being, creativity and cognition didn't improve compared with placebo (Cavanna et al.).
• Two randomized trials, published 2026. No reliable effect on cognition or mood after correcting for multiple comparisons, with participants who stayed properly blinded (Prochazkova, Marschall et al.). A pooled analysis found only a narrow gain in one measure of creative thinking (Prochazkova et al.).
• Meta-analysis, 2026. Across randomized trials in healthy adults, microdosing produced measurable subjective and brain-activity effects but "minimal impact" on cognition, creativity or lasting mood (CNS Drugs).

There's a fair counterpoint. Most trials have been small and enrolled healthy volunteers, not people with depression, so a 2024 review argued it's too early to write microdosing off as pure placebo (Polito and Liknaitzky). Placebo-controlled trials of psilocybin microdosing in people with major depression have been designed and registered, but none had reported results as of October 2026.

The risks worth knowing

• Lithium. In 62 online reports of people combining lithium with a psychedelic, 47% described seizures and 39% needed medical attention (Nayak et al., 2021). Oregon's licensed program says clients who've taken lithium in the past 30 days may be ineligible. Don't combine them.
• Antidepressants. SSRIs and SNRIs commonly weaken psilocybin's effects, which can tempt people to take more (Gukasyan et al.). Never stop an antidepressant on your own to make room for microdosing.
• Heart valves. Psilocybin's active form stimulates the 5-HT2B serotonin receptor. Long-term activation of that receptor by other drugs, like the diet drug fen-phen, damaged heart valves. Nobody has shown that microdosing does this, but nobody has studied it adequately either, which matters for a practice built on months of repeated use (Tagen et al., 2023).
• Mental health history. People with a personal or family history of psychosis or bipolar disorder are excluded from psilocybin trials for good reason. Psychedelic use has been linked to more psychotic and manic symptoms in people with that history.
• Tolerance. Tolerance to psilocybin builds quickly with use on consecutive days, which is one reason microdosing schedules include rest days.
• Unknown potency. With no regulated supply in Washington, the strength of what you have depends entirely on its source.

Our psilocybin safety guide covers interactions and warning signs in more detail.

Why measuring is harder than it looks

Because a microdose is a tiny fraction of a gram of dried mushroom, the usual problems are measurement problems: most kitchen scales can't weigh that little accurately, and potency differs between mushrooms and between parts of a mushroom. For a practical look at the measuring problem, see why a kitchen scale can't measure a microdose, written by our sister shop.

Microdosing and the law in Seattle

Microdosing gets no special treatment in Washington law. Any amount of psilocybin is a Schedule I controlled substance, and possessing it is a gross misdemeanor. Seattle's 2021 resolution makes personal possession and use a lowest police priority, which in practice covers private microdosing as much as anything. It doesn't make it legal, and it doesn't cover buying. Our Seattle law guide has the full picture.

Seattle is also home to serious research on full-dose psilocybin therapy, including the University of Washington's state-funded study in veterans and first responders and a VA trial at VA Puget Sound. Neither is studying microdosing.

Last checked against the sources above on Oct 20, 2026. Spotted something out of date? Tell us.