Education / Research

Is Microdosing Psilocybin Safe? What the Research Says

Last reviewed

The honest answer to whether microdosing is safe is that nobody knows for sure, because it has barely been studied. The best safety data comes from supervised sessions at full strength in people who were screened first. Very little of it looks at taking small amounts repeatedly, for months, outside a study.

This page goes through what we could find on side effects, medications, and the heart, and what has not been studied at all. Every study links to its source.

What the safety research shows

The studies that look at microdosing specifically are short, and most were in healthy volunteers. Surveys of microdosers describe mostly improved mood and focus, and some people also report physical discomfort or more anxiety. Our research page covers those studies in detail.

Reviews

The biggest safety review: well tolerated in research settings

A systematic review and meta-analysis pooled 214 studies of classic psychedelics, a group that includes psilocybin. Of these, 114 reported usable adverse-event data, covering 3,504 people. Non-serious effects such as headache were common, and psilocybin and LSD looked similar. No serious adverse events were reported among healthy volunteers. About 4 percent of participants who had a neuropsychiatric condition did have one, including worsening depression, suicidal behavior, psychosis, or seizures. The authors concluded these drugs were generally well tolerated in clinical and research settings.

Worth knowing

These were supervised research sessions with screened participants, not people using on their own. Events were tracked after full-strength sessions, and the review was not built to answer questions about repeated small doses. Only 16 of the 68 studies published since 2005 described a systematic way of tracking side effects, so the true rates are uncertain. The authors note that serious events reported outside research have not shown up in trial participants, so the trial results do not carry over directly.

Medications: antidepressants and lithium

Medications are where the research is most specific. Antidepressants and mood stabilizers can change what these mushrooms do, and in the case of lithium the reports are alarming. None of this is a reason to stop a prescription. It is a reason to talk to the person who prescribes it.

Small or open-label trials

Taking an SSRI first: positive effects held up, hard effects eased

In a randomized, double-blind crossover study, 23 healthy volunteers took the antidepressant escitalopram for 14 days, or a placebo, before a psilocybin session. The antidepressant did not significantly reduce the positive effects of psilocybin. It did reduce anxiety, bad drug effects, and the rise in blood pressure.

Worth knowing

Only 23 people finished, so no significant difference is not proof of no difference. The authors say 14 days may have been too short, and the findings may not apply to other antidepressants or to patients. It tested a full-strength session, not microdosing.

Case reports and surveys

Surveys: antidepressants may blunt the effect, sometimes for months

An online survey collected 611 reports from people who had used psilocybin mushrooms while on an antidepressant. Weaker-than-expected effects were reported in roughly half of the reports on SSRIs or SNRIs, and in about three in ten on bupropion, which does not act on serotonin. After people stopped an SSRI or SNRI, some still reported weaker effects for weeks to months.

Worth knowing

The reports were retrospective and self-reported, so the survey cannot prove cause, and weaker than expected is a subjective call. It is about how strong effects feel, not about safety, and it does not clear combining the two. Weaker acute effects do not necessarily mean a weaker benefit. Stopping an antidepressant is a decision for you and your doctor.

Case reports and surveys

Lithium and seizure reports

Researchers analyzed online reports from people who took a classic psychedelic while on a mood stabilizer. Of 62 reports involving lithium, 47 percent described a seizure, and 39 percent involved medical attention. Of 34 reports involving lamotrigine, none did. Most of the lithium reports involved LSD, and only six involved psilocybin.

Worth knowing

These are anonymous forum posts with no verified doses and no comparison group, and seizures are more likely to be written up than uneventful combinations, so they cannot give a rate or prove that lithium caused the seizures. The authors still call it a significant possible risk, which is why anyone taking lithium should talk to their prescriber before considering this.

Your heart

Trials of full-strength sessions report temporary rises in blood pressure and heart rate, which is one reason people with heart conditions are usually excluded. Long-term use of small amounts raises a different question.

Reviews

Heart valves: a theoretical risk for long-term use

A review asked whether taking psychedelics in small amounts for months or years could harm the heart. Psilocin, the active form of psilocybin, binds strongly to a receptor (5-HT2B) that is also hit by drugs linked to heart valve damage, such as fenfluramine and pergolide. The authors say the risk with such drugs builds with long exposure, even when they are not taken daily, and conclude that chronic microdosing may carry a risk of heart fibrosis and valve disease, but they call it uncertain.

Worth knowing

The concern comes from receptor data and from experience with other drugs. No controlled study has checked the hearts of people who microdose over a long time, and microdosing trials have mostly lasted weeks to a couple of months. The authors suggest breaks and regular heart scans in future long-term studies.

Who should talk to a doctor first

This is not medical advice, and it is not a complete list. It reflects what the studies above and the standard trial exclusions point to.

  • Psychosis, schizophrenia, or bipolar disorder. A personal or family history is a standard reason to be excluded from trials, and the safety review above found psychosis among the serious events in people with existing conditions.
  • Lithium or other mood stabilizers. The seizure reports above are the reason to check first.
  • Antidepressants. The research suggests effects can be weaker, and the evidence on safety is thin. Never stop or change a prescription on your own.
  • Heart conditions or high blood pressure. Trials report temporary rises in blood pressure and heart rate, and long-term effects on the heart valves are unstudied in people who microdose.
  • Pregnancy and nursing. We found no safety research that says anything reassuring.
  • Any other medication. Interactions are poorly studied. A pharmacist can check what you take.

What nobody has studied yet

We have not found research on the long-term effects of microdosing over months or years, on how it interacts with most prescription drugs, or on what happens in people who are older, pregnant, or living with a chronic illness. We have also not found a study that checked the heart health of regular microdosers.

Until that research exists, the advice common in the research community still applies: start low, go slowly, and do not try something new alone the first time.

Keep reading

This page is for adults 21 and older. It summarizes published research for education only. It is not medical or legal advice, and it makes no claim that any product sold by Luna treats, cures, prevents, or helps any condition. Laws about these mushrooms vary by place, and you are responsible for knowing yours.

Research moves quickly. We last checked this page against its sources on , and we will correct it if we get something wrong.