Safety first
Microdosing safety: who should not, and what to watch for
Psilocybin isn’t right for everyone, and some medicines don’t mix with it. Please read this before you order, and talk with a doctor if anything here applies to you.
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Free, and there for you. Tap a number to call.
- 911Emergency: trouble breathing, chest pain, a seizure, or someone who won’t wake up
- 988Suicide and Crisis Lifeline. Call or text 988, any time
- 1-800-222-1222Poison Help, answered by US poison centers, any time
- 62-FIRESIDEFireside Project psychedelic peer support. Call or text, 11 a.m. to 11 p.m. Pacific, every day
Who should not use psilocybin, or should talk to a doctor first
- A personal or family history of psychosis, schizophrenia or bipolar disorder. Research safety guidelines screen out these people, and anyone with a close blood relative, such as a parent, sibling, grandparent, aunt or uncle, who has them. (Johnson et al., 2008)
- Anyone taking lithium. In an analysis of 62 online reports of lithium combined with a psychedelic, 47% described seizures. (Nayak et al., 2021)
- Pregnancy or breastfeeding. A 2026 review found no studies of psilocybin and human pregnancy outcomes. No data isn’t the same as safe. (Albert and Arthur, 2026)
- Heart conditions. Psilocybin can raise blood pressure and heart rate; in one trial, blood pressure rose above 160 systolic in about a third of high-dose sessions. Talk with your doctor if you have high blood pressure or heart disease. (Griffiths et al., 2016)
- Anyone under 21. We don’t sell to anyone younger, and checkout asks every customer to confirm their age.
Medicines to raise with your clinician
Never stop, start or change a prescribed medicine on your own. Bring this list to your prescriber or pharmacist.
Antidepressants (SSRIs and SNRIs)
In a survey, people taking these often found psilocybin’s effects weaker, sometimes for months after stopping (Gukasyan et al., 2023). A small controlled trial in 23 healthy people, using a single full 25 mg dose of psilocybin, found escitalopram didn’t reduce its positive mood effects, though it did reduce anxiety and unpleasant effects (Becker et al., 2022). Either way, it’s a conversation for your prescriber.
MAOIs
A 2022 review found that true serotonin toxicity usually involves an overdose or a combination that includes an MAOI (Malcolm and Thomas, 2022), and dangerous blood-pressure spikes have been reported with MAOIs and psilocybin mushrooms (Rached et al., 2026).
Tramadol
Tramadol’s own FDA label warns of seizures and of serotonin syndrome when it’s combined with other drugs that act on serotonin. There’s no psilocybin-specific study, which is a reason for caution, not comfort. (Tramadol label, DailyMed)
Lithium and other psychiatric medicines
See the lithium note above. Antipsychotics, mood stabilizers, bupropion and others can all change how psilocybin affects you. Two systematic reviews collect what’s known (Halman et al., 2024; Sarparast et al., 2022).
Side effects people report
From surveys of people who microdose, and from blinded trials.
- Apart from problems tied to the substances being illegal, such as not knowing the dose, physical discomfort was the most common challenge in one analysis: trouble sleeping, an upset stomach, headaches or migraines, tingling, and feeling too warm or cold. (Anderson et al., 2019)
- Feeling more anxious, and dips in focus, energy or mood, in the same reports.
- About one in five of 1,116 microdosers in another survey reported a negative effect, mostly short-lived. (Hutten et al., 2019)
- In blinded trials, anxiety led some LSD microdosers to drop out (Murphy et al., 2023), and unpleasant body sensations were more common on psilocybin (Prochazkova et al., 2026).
- An open question about the heart. Researchers have raised a theoretical concern that repeated doses over long periods could affect heart valves, through a serotonin receptor called 5-HT2B. There are no good clinical studies either way. (Tagen et al., 2023)
Everyday care
- Don’t drive or use machineryafter taking psilocybin, including on days you feel nothing obvious.
- Store it safelyin its sealed package, out of reach of children and pets. If a child or pet swallows any, call Poison Help at 1-800-222-1222 or your vet right away.
- Don’t mix it with alcohol or other drugs,and check every medicine and supplement with a pharmacist.
- Tell someone you trustwhat you’re doing, and keep these numbers handy.
Warning signs: when to get help
Call 911 for chest pain, trouble breathing, a seizure, fainting or someone who won’t wake up, or a very high temperature with confusion, agitation, heavy sweating, a racing heart or muscle twitching or stiffness, which can be signs of serotonin toxicity.
Call or text 988 if you’re having thoughts of harming yourself, any time of day.
Call Poison Help at 1-800-222-1222 with questions about something someone has taken. It’s free and answered by US poison centers around the clock.
Call or text Fireside Project at 62-FIRESIDE to talk through a difficult psychedelic experience with a trained peer, from 11 a.m. to 11 p.m. Pacific every day. It isn’t an emergency or suicide line; for emergencies, call 911.
Harm-reduction resources
Independent community resources, not medical sources.
- Fireside Project: free psychedelic peer support by phone and text.
- DanceSafe: drug checking and harm-reduction education.
- TripSit’s combination chart: how common substances interact.
Quick answers on safety.
Safety questions
What are the side effects of microdosing?
In surveys and reports, people most often describe trouble sleeping, an upset stomach, headaches, feeling more anxious, and dips in focus, energy or mood. In blinded trials, some people on active doses reported more anxiety or unpleasant body sensations.
Can I take psilocybin with antidepressants?
Talk with your prescriber first, and never stop or change a prescribed medicine on your own. Antidepressants can blunt psilocybin’s effects, and some medicines, like MAOIs, lithium and tramadol, carry more serious risks.
Who should not take psilocybin?
Anyone under 21, anyone pregnant or breastfeeding, anyone with a personal or family history of psychosis, schizophrenia or bipolar disorder, anyone taking lithium, and anyone with a heart condition unless a doctor has said it’s safe.
When should I call 911?
For chest pain, trouble breathing, a seizure, fainting or someone who won’t wake up, a very high temperature with confusion or agitation, or if someone is in immediate danger of harming themselves or someone else. For thoughts of suicide, you can also call or text 988.
Our products haven’t been studied or evaluated for any condition, and nothing here is medical advice.