Medicinal Mushrooms in Pregnancy and Breastfeeding — What Is Actually Known, and Why We Say “Not Now”

Written by Shlomi Hayun, Head Grower · Scientifically reviewed by Dr. Evyatar Shaulsky, Ph.D., Yale graduate · Updated: August 25, 2026

Medicinal mushroom supplements — reishi (Ganoderma lucidum, lingzhi), lion’s mane (Hericium erinaceus, yamabushitake), cordyceps and turkey tail (Trametes versicolor, yun zhi) — are concentrated extracts of immunomodulating fungi, and in pregnancy and breastfeeding they all fall into one clear category: never studied in humans. Our short answer, as the people who grow and sell them: not during pregnancy, not while breastfeeding — unless it is a shared decision with the doctor or midwife who is following you. Not because harm has been shown, but because not a single human study has shown safety, because these are compounds that act on an immune system that is finely tuned during pregnancy, and because our extracts are alcohol tinctures. On this page we lay out what has been measured, what has not, and what a real pregnancy-safety study looks like — so that the conversation with your doctor is an informed one.

This is a page that says “no” to someone who wants to buy from us. Most answers to this question online come from two directions: brands explaining why their mushroom is “gentle and safe even in pregnancy”, and blogs warning against everything. Neither brings a study. We will bring only what has been tested — including the animal studies, including who funded them, and including the fact that a single human study of medicinal mushrooms in pregnancy simply does not exist.

Key facts

Our recommendation: avoid medicinal mushroom extracts during pregnancy and breastfeeding, and come back to them afterwards — as a shared decision with your doctor. That is also what our label says, and what Israeli law requires on every dietary supplement.
What exists: reishi and lion’s mane have developmental-toxicity studies in rats and rabbits (no harm found at the doses tested — most of them written by manufacturers); reishi also has a zebrafish-embryo assay that found toxicity at high extract concentrations. Cordyceps and turkey tail do not even have that.
What does not exist: zero studies in pregnant or breastfeeding women, for any of the four mushrooms. The U.S. National Institutes of Health lactation database (LactMed) has no monograph on any of them.
The third reason — alcohol: our extracts contain 32–33% alcohol. In a daily dose of 1.4 ml that is under half a millilitre — and still, the Israeli Ministry of Health states that no amount of alcohol is permitted in pregnancy, and we do not argue with that.
Culinary mushrooms are a different story: cooked button, shiitake and portobello mushrooms are food, not a concentrated supplement, and probably a good source of ergothioneine — an antioxidant being studied in the context of a healthy pregnancy.

Can you take medicinal mushrooms while pregnant?

Our recommendation is no — avoid medicinal mushroom extracts during pregnancy unless the doctor or midwife following your pregnancy has explicitly approved it. The reason is not a finding of harm but the absence of findings altogether: no study of reishi, lion’s mane, cordyceps or turkey tail extracts in pregnant women has ever been published, and without a study there is no way to say “safe”.

It is the same answer we have given for years on our FAQ page, in the side-effects guide and on “Who shouldn’t take lion’s mane” — what changes here is that we lay out every piece of evidence that exists, so that you can bring it to your doctor instead of just the sentence “ask your doctor”. Note the wording: “a shared decision with your doctor” is not a legal formula for us. In a survey of 170 obstetricians at seven Israeli medical centres, 58.8% reported using some form of complementary medicine themselves, and nearly two-thirds had recommended or would recommend it to pregnant patients — so this conversation is a real one, not a closed door.

Why “not studied” is the honest answer — not “safe” and not “dangerous”

Because safety in pregnancy is a claim that requires a specific kind of evidence: following women who were exposed to a substance, compared with women who were not, and counting malformations and pregnancy outcomes. Medicinal mushrooms have no such study. Whoever says “safe” is guessing optimistically, and whoever says “dangerous” is guessing pessimistically — and both guesses rest on the same zero data.

This gap is not unique to mushrooms. In a multinational study of 9,459 women from 23 countries, 28.9% reported using herbal medicines during pregnancy — most on their own initiative. In the same group’s follow-up paper, which classified 126 herbal medicines by their safety in pregnancy, 27 were classified as contraindicated, and 20% of the women had used one of them. The researchers closed with a sentence worth remembering: “The paucity of human studies on herbal medicines safety in pregnancy stands in stark contrast to the widespread use of these products among pregnant women.” And for reishi specifically, a comprehensive critical review from 2021 said it outright: clinical studies on teratogenicity, mutagenicity and genotoxicity are missing.

What has actually been measured for each mushroom — and what is it worth?

Reishi and lion’s mane have developmental-toxicity studies in laboratory animals that found no harm to the mother or the fetuses at the doses tested; reishi also has a zebrafish-embryo assay that found delayed hatching and tail malformations at high extract concentrations. Cordyceps and turkey tail have no developmental study at all. In humans — no data for any of the four.

Mushroom	What exists	Model	What it does not tell you
Reishi (Ganoderma lucidum)	Full developmental and reproductive toxicity programme under ICH guidelines on sporoderm-removed reishi spores (2025): no maternal, embryo-fetal or teratogenic toxicity in rats and rabbits up to 4 g/kg/day, about 20 times the intended dose. Two authors employed by the manufacturer. Zebrafish-embryo assay (2012): at extract concentrations of 1% and above — tail malformations, delayed hatching and dose-dependent mortality.	Rats, rabbits, fish	Not tested in humans. Shelled spores are not a fruiting-body extract; fish water is not a human dose.
Lion’s mane (Hericium erinaceus)	Developmental toxicity study (2018): 66 pregnant rats, up to 2,625 mg/kg/day of erinacine-A-enriched mycelium — no difference in fetal weight, implantation or malformations. Written by the manufacturer. 90-day study of an aqueous fruiting-body extract (2016) and a 90-day plus genotoxicity study of a β-glucan extract (2022): no adverse findings.	Rats	Not tested in humans. The developmental study used mycelium, not fruiting body.
Cordyceps	Safety review (2020) of the metabolites of Cordyceps fungi: cordycepin and pentostatin also show dose-dependent toxicities in animals and humans, and the authors could not rule out mycotoxin production.	Review	No developmental study, no pregnancy study. The mushroom with the least safety data of the four.
Turkey tail (Trametes versicolor)	90-day plus genotoxicity study of a mushroom powder (2025): no toxicity up to 2,000 mg/kg/day. Written by the manufacturer. MSKCC: “Until safety data become available, pregnant or breastfeeding women should avoid taking Coriolus.”	Rats	No developmental study, no pregnancy study.

Two honest notes on the table. First: most of the animal safety studies were written or funded by supplement manufacturers — that does not disqualify them (they were run under OECD and ICH guidelines), but it is information you are owed, and we have an interest too, which is why we say it out loud. Second: “no harm found in rats” is the first step toward a human study, not a substitute for it.

What does a real pregnancy-safety study look like? The echinacea example

Echinacea is a popular immunomodulating herb, and it received exactly what no mushroom has: a prospective cohort study of 206 women exposed to the herb (112 of them in the first trimester) against 206 matched controls, with no difference in malformation rates; followed by an analysis of 68,522 women in the Norwegian Mother and Child Cohort, in which 363 reported echinacea use in pregnancy — with no increased risk of malformations or adverse pregnancy outcomes. That is the bar.

The example matters for two reasons. First, it shows that “herbal immunomodulator” does not automatically mean dangerous in pregnancy — echinacea came out clean. Second, it shows precisely what mushrooms lack: not good intentions, but data. A 2006 systematic review concluded that echinacea is non-teratogenic in pregnancy, and added caution specifically for lactation — because the research is thin there too. And when we checked the U.S. National Library of Medicine’s lactation database (LactMed), echinacea has a monograph; reishi, lion’s mane, cordyceps and turkey tail do not. The gap between “tested and found clean” and “not tested” is the whole difference, and we are on the far side of it.

Why does an “immune modulator” call for special caution in pregnancy specifically?

Because pregnancy itself is a state of fine immune tuning — the body has to tolerate a fetus that is half genetically foreign while still protecting both of you. Beta-glucan, the main active compound in medicinal mushrooms, acts on exactly that system, through receptors on immune cells. What happens when you stimulate it during a period when it is set differently? Nobody has measured. And that is precisely the point.

A review published in July 2026 in the journal Molecules, by an obstetrics group from Novi Sad, set out the background: pregnancy involves profound metabolic, hormonal and immunological adaptations, and mushrooms contain immunomodulating compounds — which is why, they write, “clinical evidence remains limited” and controlled trials are needed to establish efficacy, safety and intake. We agree with every word. The full explanation of how beta-glucan works is on our beta-glucan page — and once you read it, you will understand why “immune support” is exactly the kind of action you want to know more about before starting in pregnancy.

What about the alcohol in the tincture?

Our extracts are 32–33% alcohol tinctures. In a daily dose of 1.4 ml that is under half a millilitre of alcohol per day — a very small amount, and we show the arithmetic transparently. But the Israeli Ministry of Health states that “there is no amount of alcohol that is permitted in pregnancy”, and that is also the position of the UK’s NHS and of the American College of Obstetricians and Gynecologists. We do not use this arithmetic to argue “so it’s fine” — we present it so that the conversation with your doctor is grounded.

Why alcohol at all? Because it is the solvent that pulls out the triterpenoids (in reishi) and the fat-soluble compounds, and it is the tincture’s natural preservative — we explained this on the storage page. Alcohol-free glycerin tinctures exist on the market; we do not make them, and it is important to say honestly that they have not been studied in pregnancy either — removing the alcohol removes one of three reasons, not all of them. If you are weighing formats, the full comparison is in “Powder, capsules or tincture”.

Breastfeeding — what changes, and what doesn’t?

In breastfeeding the question changes: not “what crosses the placenta” but “what passes into milk, and what does it do to the baby”. Here too there are no data: it is not known whether mushroom compounds pass into breast milk, in what amount, or what they do to an infant whose immune system and liver are still maturing. So our recommendation is the same — avoid while breastfeeding, unless it is a shared decision with a doctor or lactation consultant.

Two things are worth noting. First — the only beta-glucan lactation trial we could find is the Australian BLOOM study, which tests yeast-derived beta-glucan (not mushroom) as a milk-supply aid after preterm birth — and as of its protocol publication in 2024, it was still at the planning stage. Second — in a survey of 173 nurse-midwives in Israel, 48.6% reported personal use of herbal medicine, and the large majority (87.3%) some form of complementary medicine. In other words, your lactation consultant or midwife probably knows the question — and it is worth asking them, with this page in hand.

I took a tincture before I knew I was pregnant — now what?

Stop, tell your doctor at the next visit, and do not panic. In a PubMed search we ran, we found no human case report of harm to a pregnancy from reishi, lion’s mane, cordyceps or turkey tail extract — and the animal studies that exist found no harm at the doses tested. “Not studied” cuts both ways: it does not let us promise safety, but it is not evidence of risk either.

The situation is more common than it seems. The echinacea researchers opened their study with exactly this point: since at least half of all pregnancies are unplanned, many women use the herb in the first trimester without knowing. If that happened to you with a mushroom tincture, the only relevant information is the table above — take it to your doctor.

What about culinary mushrooms in pregnancy — shiitake, button, portobello?

Cooked culinary mushrooms are food, not a concentrated supplement, and they are not covered by the caution on this page. They are also the main dietary source of ergothioneine — an antioxidant that, in a cohort of 432 first-time mothers (SCOPE), showed an intriguing association with pre-eclampsia: of the 97 women who developed it, only one was in the top decile of blood ergothioneine. That is an observational finding, not proof of cause, and you can read it in full in the sources.

The distinction between food and extract is the heart of this page. A plate of cooked mushrooms delivers a few grams of mushroom in a form humans have eaten for thousands of years, pregnancy included. One of our extracts delivers, in every 50 ml, the material of 16–25 grams of fresh mushroom after seven weeks of alcohol extraction — an entirely different product, and therefore an entirely different question. If you want to understand exactly what is in the bottle, the process is in “Fresh vs. dried mushroom extract” and the numbers are on the lab-testing page. And if for now you prefer your mushrooms on a plate — that is exactly what we would do in your place.

Reishi mushroom growing at Triterra Farm, with guttation droplets on the fruiting body — Reishi growing on the farm. What we grow, we also measure — but in pregnancy, the missing measurement is not of the mushroom; it is of the woman.

What does the label say — and why does Israeli law require that sentence?

Every dietary supplement in Israel must carry, under the Dietary Supplements Regulations, the sentence: “Pregnant women, nursing women, people taking prescription medication and children — consult a physician.” That sentence is on our bottles too — not as a legal hedge, but because it is true: the law does not require the manufacturer to prove safety in pregnancy, so it hands the decision to the doctor.

It is worth understanding what the regulation checks and what it does not: proper manufacturing, Hebrew labelling and a warning sentence — not a pregnancy-safety study, and not measurement of an active compound. We wrote about all of this on the regulation page. The practical meaning: “Ministry of Health approved” on a mushroom supplement says nothing about pregnancy — not ours, and not anyone else’s. The U.S. framework (DSHEA) likewise requires no pre-market pregnancy-safety testing of supplements.

What do the institutional sources say?

The same thing, in different words: not known. Memorial Sloan Kettering’s About Herbs monograph on turkey tail says pregnant or breastfeeding women should avoid it until safety data exist. WebMD says of reishi to “stay on the safe side and avoid use”, and of lion’s mane and cordyceps that “it is not known if or how” they could affect pregnancy. No institutional source writes “safe”.

Source	What it says	About
Israeli Ministry of Health (Dietary Supplements Regulations)	Mandatory sentence on every supplement: pregnant and nursing women — consult a physician	All dietary supplements
Israeli Ministry of Health (alcohol in pregnancy)	“There is no amount of alcohol that is permitted in pregnancy”	Alcohol tinctures
MSKCC (About Herbs)	“Until safety data become available, pregnant or breastfeeding women should avoid taking Coriolus”	Turkey tail (Coriolus)
WebMD	“There isn’t enough reliable information… Stay on the safe side and avoid use”	Reishi
WebMD	“It is not known if or how [it] could affect pregnancy or harm a fetus”	Lion’s mane, cordyceps
LactMed (NIH)	No monograph for any of the four mushrooms	Breastfeeding

When do you come back — and how?

After breastfeeding ends, and at our usual pace for any beginner: a low dose, gradual increase, and attention to your body in the first weeks. There is no special “return protocol” after birth — because there is no such study, and we do not invent them. What there is: the dosage guide, and the timing and stacking page, which explains why consistency matters more than the hour you take it.

And if the question is “which mushroom is even right for me after this period” — our matching quiz asks, at its safety gate, precisely the question “Are you pregnant or nursing?”, because it was built not to recommend to anyone whose answer is yes. The recommendation will wait. The mushrooms will keep growing in the Galilee, and when you return they will be there, with the same open test report.

What this page does not say — and what we do not claim

We do not say medicinal mushrooms are dangerous in pregnancy — there is no evidence of that. We do not say they are safe — there is no evidence of that either. We do not give a “reduced pregnancy dose”, because no such dose exists in any study. And we do not say the alcohol is “negligible” — only that it is small, and that the decision about “small” in pregnancy is not ours to make.

What has been measured on our side was measured on the extract, not on pregnant women. That is the distinction to take from here: the numbers below say what is in the bottle, and only that.

Extract	Beta-glucan (dry basis)	Alpha-glucan (starch)
Cordyceps	28.16%	Not detected
Reishi	25.65%	Not detected
Lion’s mane	23.93%	Not detected
Turkey tail + reishi	23.21%	Not detected

Tested at TÜV Austria on the finished extract, per extract; the certificates are open, and if you want to learn to read one yourself, the full walk-through is in “How to read a mushroom supplement COA”. They answer the question “what is inside” — not the question “is it fine in pregnancy”. On the second, science has not yet answered, and neither have we.

Here for someone else, or planning for the period after? Our extracts — fresh fruiting bodies from our farm in the Galilee, a seven-week extraction, and an open lab test for each extract — come with a 100-day trial and free shipping over ₪285. The matching quiz takes two minutes, and includes the safety gate we described here. Take the quiz All extracts

The bottom line

In pregnancy and breastfeeding — no, unless it is a shared decision with your doctor. Not because of a finding of harm, but because of three facts that do not go away when you switch brands: zero human studies, an action on an immune system that is finely tuned, and alcohol in the bottle. The animal studies that exist are reassuring, not conclusive; the real bar — the one echinacea cleared — has not yet been built for any mushroom. Culinary mushrooms on a plate are a different story, and a good one. When you come back, we are here — with the same numbers on the same extract, and the same honest answer about what has not yet been measured.

Frequently asked questions

Is reishi safe during pregnancy?

Not known. There is no study of reishi in pregnant women. A 2025 developmental-toxicity study in rats and rabbits found no harm, and a 2012 zebrafish-embryo assay found toxicity at high extract concentrations — neither is human data. Our recommendation: avoid, and talk to your doctor.

Is lion’s mane safe during pregnancy?

Not studied in humans. A study in pregnant rats (2018) found no effect on the fetuses at the doses tested, but it used mycelium and was written by the manufacturer. WebMD sums it up: it is not known if or how lion’s mane could affect pregnancy. We recommend avoiding it and consulting your doctor.

Can I take cordyceps while pregnant?

Cordyceps does not even have a developmental study in animals, and a 2020 safety review notes dose-dependent toxicity of some of its metabolites. Of the four mushrooms it has the least safety data — our recommendation to avoid it in pregnancy is the most unambiguous here.

Can I take medicinal mushrooms while breastfeeding?

Our recommendation is no, unless it is a shared decision with a doctor or lactation consultant. It is not known whether mushroom compounds pass into breast milk or in what amount, and the NIH’s LactMed lactation database has no monograph on any of them.

How much alcohol is in a dose of the tincture?

Our extracts contain 32–33% alcohol, and in a daily dose of 1.4 ml that is under half a millilitre of alcohol. The Israeli Ministry of Health states that no amount of alcohol is permitted in pregnancy, so we do not use this arithmetic as an argument — only as information for the conversation with your doctor.

I took a tincture before I knew I was pregnant — should I worry?

Stop and tell your doctor, without panic. In a PubMed search we found no human case report of harm to a pregnancy from these mushroom extracts, and the existing animal studies found no harm at the doses tested. “Not studied” is not evidence of risk — it is only the reason we cannot promise.

Are culinary mushrooms okay in pregnancy?

Yes — cooked button, shiitake and portobello mushrooms are ordinary food and are not covered by the caution here. They are also the main dietary source of ergothioneine, an antioxidant observationally linked to lower pre-eclampsia risk in the SCOPE cohort. A concentrated extract is an entirely different product.

When can I go back to the tincture after giving birth?

After breastfeeding ends, at our usual pace for any beginner — a low dose and gradual increase per the dosage guide. There is no special post-birth protocol, because there is no such study; if there is a medical condition or regular medication, the decision goes through your doctor.

Scientific sources (peer-reviewed)

Liu J, Song Y, Chen C, et al. Developmental and reproductive toxicity assessment of sporoderm-removed Ganoderma lucidum spores. Frontiers in Cell and Developmental Biology, 2025;13:1705415. PubMed
Dulay RM, Kalaw SP, Reyes RG, Alfonso NF, Eguchi F. Teratogenic and toxic effects of Lingzhi or Reishi medicinal mushroom, Ganoderma lucidum, on zebrafish embryo as model. International Journal of Medicinal Mushrooms, 2012;14(5):507-512. PubMed
Ahmad R, Riaz M, Khan A, et al. Ganoderma lucidum (Reishi) an edible mushroom; a comprehensive and critical review of its nutritional, cosmeceutical, mycochemical, pharmacological, clinical, and toxicological properties. Phytotherapy Research, 2021;35(11):6030-6062. PubMed
Li IC, Chen WP, Chen YP, Lee LY, Tsai YT, Chen CC. Acute and developmental toxicity assessment of erincine A-enriched Hericium erinaceus mycelia in Sprague-Dawley rats. Drug and Chemical Toxicology, 2018;41(4):459-464. PubMed
Lakshmanan H, Raman J, David P, Wong KH, Naidu M, Sabaratnam V. Haematological, biochemical and histopathological aspects of Hericium erinaceus ingestion in a rodent model: a sub-chronic toxicological assessment. Journal of Ethnopharmacology, 2016;194:1051-1059. PubMed
Chen SN, Chang CS, Yang MF, Chen S, Soni M, Mahadevan B. Subchronic toxicity and genotoxicity studies of Hericium erinaceus β-glucan extract preparation. Current Research in Toxicology, 2022;3:100068. PubMed
Chen B, Sun Y, Luo F, Wang C. Bioactive metabolites and potential mycotoxins produced by Cordyceps fungi: a review of safety. Toxins, 2020;12(6):410. PubMed
Mahadevan K, Daoust J, Brendler T, Chaudhary A, Saifi A, Garg VK. A toxicological assessment of Hericium erinaceus (Lion’s mane) and Trametes versicolor (Turkey tail) mushroom powders. Frontiers in Toxicology, 2025;7:1651442. PubMed
Kennedy DA, Lupattelli A, Koren G, Nordeng H. Herbal medicine use in pregnancy: results of a multinational study. BMC Complementary and Alternative Medicine, 2013;13:355. PubMed
Kennedy DA, Lupattelli A, Koren G, Nordeng H. Safety classification of herbal medicines used in pregnancy in a multinational study. BMC Complementary and Alternative Medicine, 2016;16:102. PubMed
Gallo M, Sarkar M, Au W, et al. Pregnancy outcome following gestational exposure to echinacea: a prospective controlled study. Archives of Internal Medicine, 2000;160(20):3141-3143. PubMed
Heitmann K, Havnen GC, Holst L, Nordeng H. Pregnancy outcomes after prenatal exposure to echinacea: the Norwegian Mother and Child Cohort Study. European Journal of Clinical Pharmacology, 2016;72(5):623-630. PubMed
Perri D, Dugoua JJ, Mills E, Koren G. Safety and efficacy of echinacea during pregnancy and lactation. Canadian Journal of Clinical Pharmacology, 2006;13(3):e262-e267. PubMed
Stajić D, Bogavac M, Stojić M, et al. Edible and medicinal mushrooms as sources of bioactive molecules in pregnancy: potential impact on preeclampsia and gestational diabetes outcomes. Molecules, 2026;31(13):2355. PubMed
Kenny LC, Brown LW, Ortea P, Tuytten R, Kell DB. Relationship between the concentration of ergothioneine in plasma and the likelihood of developing pre-eclampsia. Bioscience Reports, 2023;43(7):BSR20230160. PubMed
Grzeskowiak LE, Rumbold AR, Williams L, et al. Effect of brewer’s yeast or beta-glucan on breast milk supply following preterm birth: the BLOOM study — protocol for a multicentre randomised controlled trial. International Breastfeeding Journal, 2024;19(1):43. PubMed
Samuels N, Zisk-Rony RY, Many A, et al. Use of and attitudes toward complementary and alternative medicine among obstetricians in Israel. International Journal of Gynecology & Obstetrics, 2013;121(2):132-136. PubMed
Samuels N, Zisk-Rony RY, Singer SR, et al. Use of and attitudes toward complementary and alternative medicine among nurse-midwives in Israel. American Journal of Obstetrics and Gynecology, 2010;203(4):341.e1-7. PubMed

Institutional sources: Israeli Ministry of Health — Alcohol in pregnancy (Hebrew) · MSKCC About Herbs — Coriolus versicolor · MSKCC About Herbs — Reishi · NHS — Drinking alcohol while pregnant · ACOG — Tobacco, alcohol, drugs and pregnancy · LactMed (NIH) — Drugs and Lactation Database.