Magic mushrooms and pregnancy: what is known, and what isn’t

People ask about magic mushrooms and pregnancy for many reasons. Some used mushrooms before they knew they were pregnant. Some are breastfeeding and curious about psilocybin for low mood. Some have read that psilocybin is being studied as a medicine and wonder whether that makes it safe. These are reasonable questions, and they deserve straight answers.

The straight answer is that science knows very little. This guide explains what has been studied, what has not, why the gap exists, and who in Canada can help. It does not tell anyone what to do, and it gives no amounts or instructions.

Are magic mushrooms safe during pregnancy?

Nobody can say they are. That is not the same as saying harm is proven. It means the question has not been studied in people in any meaningful way.

MotherToBaby, a pregnancy and breastfeeding information service run by the Organization of Teratology Information Specialists, says studies have not been done to see whether taking magic mushrooms raises the chance of miscarriage, birth defects, preterm birth, low birth weight, or later behaviour or learning problems in the child. It adds that it is not known whether magic mushrooms make it harder to get pregnant (MotherToBaby, fact sheet dated 1 April 2025).

CAMH, Canada’s largest mental health hospital, says that although research is scarce, taking hallucinogens during pregnancy may affect the development of the baby and increase the chance of miscarriage (CAMH, hallucinogens). That is a general caution about hallucinogens as a group, not a result from a psilocybin study. Evidence: unresolved.

The most useful single sentence comes from a 2026 scoping review by Canadian family-medicine authors: the absence of eligible pregnancy outcome data for psilocybin “must not be interpreted as evidence of safety” (Albert and Arthur, 2026).

Why do psilocybin trials exclude pregnant and breastfeeding people?

The clinical trials that made psilocybin famous were not designed to answer pregnancy questions, and most were designed to keep pregnancy out. We checked the eligibility criteria registered on ClinicalTrials.gov for several of them:

• A 2021 trial of psilocybin-assisted therapy for major depression, published in JAMA Psychiatry, excluded women who were pregnant, checked with a urine pregnancy test at intake and before each drug session, or nursing. It also excluded sexually active women who could become pregnant and were not using effective birth control (NCT03181529).
• The single-dose psilocybin trial for major depressive disorder published in JAMA in 2023 excluded women who were pregnant, intended to become pregnant during the study or were nursing (NCT03866174).
• The trial comparing psilocybin with escitalopram for depression excluded a positive pregnancy test at screening or during the study, women planning a pregnancy and women nursing or breastfeeding (NCT03429075).
• A trial of psilocybin for psychological and existential distress in palliative care lists “pregnancy or lactation” as an exclusion (NCT04754061).

Some registry entries, including those for the large COMP360 trials, show only brief “key” criteria, so we cannot say from the registry alone how they handled pregnancy. The pattern across the entries we could read is consistent, though. Results from these trials, covered in our article on psilocybin for depression, tell us nothing about pregnancy because pregnant and breastfeeding people were not in them.

This is not unique to psilocybin. The 2026 scoping review notes that pregnancy-specific safety evidence for many drugs is limited because pregnant and breastfeeding people are commonly excluded from clinical trials. That leaves clinicians relying on observational data, case reports and teratology information services (Albert and Arthur, 2026). Excluding pregnant people protects them from an untested drug, but it also means the gap never closes on its own.

What human evidence exists on psilocybin in pregnancy?

Very little, and none of it is specific to psilocybin outcomes. Two recent reviews searched for it.

The 2026 scoping review searched five major medical databases from their start to March 2025 for human studies of pregnancy exposure to MDMA, psilocybin, LSD, mescaline and DMT or ayahuasca. It found 23 eligible sources, published between 1968 and 2020: 11 on MDMA, 11 on LSD and 1 on mescaline or peyote. It found no eligible primary human pregnancy outcome studies for psilocybin. The sources it did find were mostly small cohorts, follow-up reports from teratology services and case reports, often limited by self-reported use, use of several substances at once and inconsistent outcome definitions (Albert and Arthur, 2026). Evidence: established that the human data for psilocybin are missing.

A second, broader review posted in 2026 as a preprint, meaning it had not yet been peer reviewed when we read it, included 42 studies covering 251 women exposed to a psychedelic during or before pregnancy. LSD was the substance in about nine in ten studies, more than half the studies were case reports, and most were published before 2000. The authors rated the certainty of evidence for every outcome as very low and called for robust research (Sun et al., 2026 preprint). We could read only the abstract, so we cannot say how many of the women, if any, were exposed to psilocybin.

Why not borrow the answer from other drugs? The scoping review warns against it. MDMA works differently from psilocybin, so findings from MDMA studies should not be applied to classic psychedelics (Albert and Arthur, 2026). Old LSD reports, often involving several drugs, cannot stand in for psilocybin either.

What do animal studies show?

Animal studies are a weak guide to people, but they are most of what exists. Everything in this section is from animals, not humans.

On pregnancy itself, MotherToBaby says a single animal study showed no increased chance of birth defects (MotherToBaby). One animal study cannot rule out risk in people, and the fact sheet does not describe it further. Evidence: preliminary, animal only.

After birth, a 2025 mouse study points the other way. Researchers gave a single dose of psilocybin to mouse mothers in the first week after giving birth. It did not ease the effects of a social stress model, and weeks later the treated mothers were more anxious, whether or not they had been stressed. Female mice that had never given birth were not affected in the same way. The offspring of treated mothers showed anhedonia, a reduced response to reward, in adulthood (Hatzipantelis et al., 2025).

The same study found psilocin, the active form of psilocybin, in the brains of nursing pups after their mothers were dosed: in 60% of samples at 30 minutes, 80% at one hour and all samples at two hours. The authors read this as psilocin passing into breast milk. Psilocybin also sharply disrupted maternal care at the time. The authors wrote that, before their work, there had been no clinical or preclinical safety testing of psilocybin in the postpartum period (Hatzipantelis et al., 2025).

What this does and does not mean: it is one study, in mice, with injected psilocybin in a laboratory. It does not show what would happen in a person, and it is not a measure of risk. It does show that the postpartum period can change how psilocybin acts, which is a reason for caution, not reassurance. Evidence: preliminary, animal only.

What about magic mushrooms and breastfeeding?

MotherToBaby says magic mushrooms have not been studied during breastfeeding and that it is not known if or how they could affect a nursing child. It says that if a parent who has taken magic mushrooms while breastfeeding suspects the baby has symptoms, such as trouble feeding, sleeping or breathing, they should contact the child’s health care provider, and that parents should talk to their own provider about breastfeeding questions (MotherToBaby).

We searched the US National Library of Medicine’s Drugs and Lactation Database (LactMed) records indexed in PubMed and found no entry for psilocybin. The only human information we found on breastfeeding is the absence of studies. The mouse data above are the only direct evidence that psilocin may reach a nursing infant. Evidence: unresolved.

Some people ask because psilocybin is being studied for postpartum depression. The authors of the mouse study note that trials of a psilocybin-related compound for postpartum mood are under way (Hatzipantelis et al., 2025). A trial in progress is not a result. If you are struggling with your mood after having a baby, the Government of Canada’s guide says to talk to your health care provider if you think you may be depressed (Government of Canada).

How strong is the evidence, question by question?

Why is the research missing, and how could it be done?

Testing an unproven drug on pregnant people in a randomized trial would raise serious ethical problems, so that design is unlikely. The realistic routes are observational. The scoping review calls for structured pregnancy drug-safety monitoring and ethically designed ways of gathering evidence as psychedelic research expands (Albert and Arthur, 2026).

• Pregnancy registries, which follow people who were exposed, often before they knew they were pregnant, and compare outcomes with similar people who were not.
• Teratology information services, which record calls about exposures and follow up after birth.
• Large population studies that link health records, which can find rare outcomes but struggle to measure what was taken.

Each route has problems for magic mushrooms. The scoping review lists under-reporting, use of several substances at once and variable drug purity as features of this kind of evidence (Albert and Arthur, 2026). The amount of psilocybin in mushrooms varies, which our article on mushroom potency claims explains. Stigma and legal risk also make people less likely to report use. All of this means the gap is likely to close slowly.

What if I used mushrooms before I knew I was pregnant?

This is common enough that the scoping review describes exposure during early, unrecognized pregnancy as clinically plausible (Albert and Arthur, 2026). No study can tell you what it means for your pregnancy, in either direction. The person who can help is your doctor, midwife or pharmacist.

It can feel hard to raise drug use with a health professional. Canadian guidance is written to make that conversation safer. The Society of Obstetricians and Gynaecologists of Canada’s 2011 guideline on substance use in pregnancy says providers should take a flexible approach, encourage community resources, and counsel women about the risks of drug use around conception, during pregnancy and after birth (SOGC, Wong et al., 2011). That guideline is from 2011 and may have been updated since. The Government of Canada’s pregnancy guide, writing about alcohol, tells people who drank before they knew they were pregnant to talk to their health care provider to learn more (Government of Canada). The same honest conversation applies to other substances.

A health professional can also check things this article cannot, such as other medicines you take. Our article on magic mushrooms and antidepressants covers what is known about mixing them. Do not stop or change a prescribed medicine on your own; the pregnancy guide says to speak to your health care provider about your medications (Government of Canada).

Where to get confidential help in Canada

• Emergency: call 911 if someone is unconscious, not breathing or having a seizure, or if anyone’s safety is at risk.
• Possible poisoning, including a wild mushroom someone ate, in Ontario: the Ontario Poison Centre on 1-800-268-9017 (toll-free) or 1-844-POISON-X (1-844-764-7669). The centre says it is available by phone 24 hours a day, every day of the year. Across most of Canada, 1-844-POISON-X (1-844-764-7669) also reaches a poison centre; Québec keeps its own number, 1-800-463-5060.
• Suicide crisis: 9-8-8, the Suicide Crisis Helpline, which you can call or text, 24 hours a day, every day of the year (9-8-8).
• Support after a difficult experience: CAMH’s page lists CAMH Access (416-535-8501, press 2), ConnexOntario and Kids Help Phone (1-800-668-6868) (CAMH). These are support and treatment-access lines, not emergency services.
• For pregnancy and breastfeeding questions: your doctor, midwife, nurse or pharmacist.

We did not find a Canadian telephone line specifically for questions about drugs in pregnancy on an official page we could verify, so we have not listed one. More numbers are on our safety page. Picking wild mushrooms carries its own poisoning risk, covered in our misidentification guide.

What is still unknown

• Whether psilocybin or magic mushrooms change the chance of miscarriage, birth defects, preterm birth or low birth weight in people. No human studies (unresolved).
• Whether exposure before birth affects a child’s later behaviour, learning or mental health. No human studies (unresolved).
• Whether, and how much, psilocin passes into human breast milk, and what it might do to a nursing baby. Only one mouse study (unresolved).
• Whether the lasting effects seen in mouse mothers after birth have any parallel in people (unresolved).
• Whether timing in pregnancy matters, or whether one use differs from repeated use. Not studied (unresolved).
• Whether psilocybin affects fertility. MotherToBaby says this is not known (unresolved).

None of these gaps means the risk is small. It means nobody has measured it. For a wider view of what is known about short- and long-term effects in general, see magic mushroom effects and are magic mushrooms safe?. Research moves, so check the date at the top of this page.

Shroomverse sells mushroom products. This article is general information about health research. It is not medical, legal or purchasing advice, and it does not recommend any product.