Nobody has measured whether reishi, lion's mane, cordyceps, chaga or turkey tail compounds pass into breast milk. The NIH's LactMed database, the standard reference for medicines in breastfeeding, has no entry for any of them. Its only Amanita entry covers death cap poisoning. So the honest answer to "is this mushroom supplement safe while breastfeeding?" is that it hasn't been studied. With Amanita muscaria and panther cap, though, there are good reasons to say no outright.
There's no lactation data for medicinal mushroom supplements, and the NHS says not enough is known about herbal remedies to guarantee they're safe while breastfeeding. Cooked culinary mushrooms are ordinary food and fine. Avoid Amanita muscaria and panther cap entirely: their compounds act on the brain, and in a series of nine child poisonings, four children had seizures or twitching. For reishi, lion's mane and similar supplements, the cautious default is to wait until you've stopped breastfeeding, or decide with your doctor.
This is a safety guide, so there's nothing to buy here. Your GP, midwife, health visitor or pharmacist can look at your circumstances. What follows explains the reasoning so you know what to ask. If you're still pregnant, our pregnancy guide covers that stage.
Has Anyone Studied Mushroom Supplements in Breastfeeding?
No. LactMed, run by the US National Library of Medicine, summarises what's known about thousands of drugs and herbs in breast milk. It has entries for common herbs such as fenugreek and fennel. It has none for reishi, lion's mane, cordyceps, chaga, turkey tail or shiitake extract. Our searches of PubMed found no study measuring any medicinal mushroom compound in human milk.
Its one Amanita entry concerns amatoxins, the liver toxins in death cap (Amanita phalloides), not the compounds in Amanita muscaria. It notes that two infants developed raised liver enzymes after nursing when their mothers had eaten an Amanita species, although two well-documented cases found no toxin in the milk. It advises that mothers with suspected Amanita poisoning probably shouldn't breastfeed until they've recovered or the milk has been tested.
The NHS position on herbal products is short: not enough is known about herbal remedies to guarantee they're safe when breastfeeding. Mushroom supplements fall into that category. They're sold as food supplements, so nobody had to prove they were safe for nursing infants before they went on sale.
Why Is "No Data" a Reason for Caution?
Because infants handle substances differently from adults. Newborns clear many compounds more slowly, because their liver and kidneys are still maturing. A dose that does nothing noticeable to a parent can build up in a small baby. That's why LactMed gives specific infant risk information for each medicine, and why "it's natural" isn't a safety argument.
Whether a compound reaches milk depends on its size, how it binds in the blood and how much reaches the bloodstream at all. Large polysaccharides such as beta-glucans are poorly absorbed in adults, which suggests little would pass into milk. Smaller molecules, such as triterpenes in reishi or the active compounds in Amanita, are more plausible candidates. But plausible isn't measured. For every mushroom supplement, that measurement is missing.
There's also a practical point. During breastfeeding you're one of two people affected by side effects. A supplement that upsets your stomach, disturbs your sleep or interacts with a medicine you've been prescribed after birth matters more now than at other times.
Why Should You Avoid Amanita Completely?
Because its compounds act directly on the brain, and young children are clearly sensitive to them. Benjamin described nine children admitted to a Seattle children's hospital after eating Amanita pantherina (eight cases) or Amanita muscaria (one case). Most were toddlers. Symptoms began within 30 to 180 minutes.
The children had central nervous system depression, unsteadiness, drifting consciousness, hallucinations and agitation. Four of the nine had seizures or myoclonic twitching that needed anticonvulsant treatment. All recovered fully. That was direct ingestion rather than exposure through milk, but it shows how strongly these compounds affect a small developing brain.
Nobody knows how much muscimol or ibotenic acid reaches breast milk. Muscimol is a small, water-soluble molecule that acts on GABA receptors, the same broad system targeted by many sedatives. For sedating medicines, sleepiness and poor feeding in the baby are the usual concerns. There's no reason to assume Amanita is gentler.
There's a second risk, too. Amanita can impair your own alertness, coordination and judgement. Moss and Hendrickson's poison-centre review found gastrointestinal symptoms in 35% of Amanita muscaria cases and 80% of panther cap cases. Being drowsy, confused or vomiting while caring for a newborn is a hazard in itself. Our who should avoid panther cap and Amanita muscaria side effects guides both list breastfeeding as a reason to stay away.
What about a microdose?
The same applies. A small dose doesn't solve the missing data on milk transfer, and you can't predict a batch's potency precisely. If you were using Amanita before or during pregnancy, the time to restart, if at all, is after you've stopped breastfeeding.
How Do Common Mushroom Supplements Compare?
All of them lack lactation data, but they don't carry equal concern. Here's how we'd rank them, based on what's known about each in adults.
| Product | Lactation data | Known adult concerns | Practical default while breastfeeding |
|---|---|---|---|
| Cooked culinary mushrooms | Ordinary food | Allergy in a few people | Fine to eat |
| Reishi | None | Rare liver injury reports; may lower blood pressure and glucose | Defer, or decide with your doctor |
| Lion's mane | None | Few reported problems; allergy possible | Defer, or decide with your doctor |
| Cordyceps | None | Hormone-related lab data; may affect glucose | Defer, or decide with your doctor |
| Chaga | None | Very high oxalate; kidney injury case reports | Avoid |
| Turkey tail | None | Mostly studied with cancer treatment | Defer, or decide with your doctor |
| Amanita muscaria, panther cap | None | Psychoactive; seizures in poisoned children | Avoid |
| Multi-herb "mood" or "energy" blends | Depends on ingredients | May include stimulants or strong herbs | Avoid unless every ingredient is cleared |
Why is chaga on the avoid list?
Because its known problem is cumulative. Chaga is extremely high in oxalate, and there are case reports of kidney damage after long-term use, including a 2022 Korean case of oxalate nephropathy. That risk exists outside breastfeeding too, but there's no reason to take it on now. Our chaga side effects guide and oxalates article give the detail.
What about reishi's liver reports?
They're rare, but real. Published cases include hepatotoxicity linked to a reishi formulation in 2004 and a fatal case associated with reishi powder in 2007. Causation in such reports is hard to prove, and millions of people use reishi without problems. But with no lactation data at all, a rare adult risk is one more reason to wait. Our reishi side effects article covers the cases.
Are Culinary Mushrooms Fine to Eat?
Yes. Cooked button, chestnut, oyster, shiitake and other shop-bought mushrooms are ordinary food, and there's no reason to cut them out while breastfeeding. They add fibre, B vitamins and, in UV-exposed varieties, some vitamin D. Our mushrooms and vitamin D guide explains which ones.
Two sensible precautions apply. Cook shiitake thoroughly, because raw or undercooked shiitake can cause an itchy, whip-like rash called shiitake dermatitis. And don't forage. Misidentification is the main way people end up eating Amanita, including the deadly ones covered by LactMed's entry.
Vitamin D is worth a mention, because it's the one supplement routinely recommended in breastfeeding. The NHS advises that breastfed babies get a daily supplement of 8.5 to 10 micrograms of vitamin D from birth, whether or not you're taking one yourself. That's for the baby, and it comes as infant drops, not from your diet or mushrooms.
What Should You Do If You Want to Take One Anyway?
Make it a deliberate decision rather than a default. If you and your doctor decide a non-psychoactive mushroom supplement is reasonable, these steps keep the risk as low as possible.
- Talk to a professional first. Your GP, health visitor or pharmacist can check the product against any medicines you're taking. The Breastfeeding Network's drug factsheets are another source the NHS points to.
- Choose a single-ingredient product. Blends multiply the unknowns. Our guide to reading a mushroom supplement label shows how to check what's actually in it.
- Check contamination data. Heavy metals and mould matter more when an infant is downstream. See our heavy metals guide.
- Start after feeding settles. The first weeks, especially with a premature or unwell baby, are the worst time to add anything new.
- Watch the baby. Stop if you notice unusual sleepiness, poor feeding, rash, diarrhoea or irritability, and tell your health visitor.
- Watch yourself. Stop if you get a rash, digestive upset or any sign of a reaction. Our mushroom allergy guide lists the symptoms.
Most of the benefits people take mushroom supplements for, such as focus, calm or immune support, can wait a few months. If they can't, that's a conversation to have with your doctor rather than a supplement shelf.
Frequently Asked Questions
Can I take reishi while breastfeeding?
It hasn't been studied. There's no data on whether reishi compounds pass into breast milk, and the NHS says not enough is known about herbal remedies to guarantee their safety in breastfeeding. Rare adult liver injury reports add a further reason for caution. The cautious default is to wait or decide with your doctor.
Is lion's mane safe while breastfeeding?
Nobody knows. LactMed, the NIH breastfeeding database, has no entry for lion's mane, and no study has measured its compounds in milk. It has few reported problems in adults, but that isn't evidence of safety for a nursing infant. Talk to your doctor before taking it.
Can I microdose Amanita muscaria while breastfeeding?
No. Its compounds act directly on the brain, nobody has measured how much reaches milk, and young children are clearly sensitive: four of nine children in one hospital series had seizures or twitching after eating Amanita. It can also impair your own ability to care for your baby.
Is it safe to eat mushrooms while breastfeeding?
Yes, cooked culinary mushrooms are ordinary food. Cook shiitake thoroughly to avoid shiitake dermatitis, and never eat foraged wild mushrooms unless an expert has identified them. LactMed notes infant liver enzyme rises after mothers ate a toxic Amanita species.
Do mushroom supplements increase milk supply?
There's no evidence that any mushroom supplement does. Herbal galactagogues such as fenugreek have been studied with mixed results, but mushrooms aren't among them. If you're worried about supply, a midwife, health visitor or lactation consultant is the right first call.
Related Articles
- Mushroom Supplements During Pregnancy
- Mushroom Supplements for Children
- Mushroom Supplements and Medication Interactions
- Mushroom Supplements and Birth Control
- Who Should Avoid Amanita Pantherina?
- Chaga Side Effects and Interactions
Sources
- Drugs and Lactation Database (LactMed). Amanita mushroom poisoning. Bethesda (MD): National Institute of Child Health and Human Development. PubMed 30372000
- Benjamin DR. Mushroom poisoning in infants and children: the Amanita pantherina/muscaria group. J Toxicol Clin Toxicol. 1992;30(1):13-22. PubMed 1347320
- Moss MJ, Hendrickson RG. Toxicity of muscimol and ibotenic acid containing mushrooms reported to a regional poison control center from 2002-2016. Clin Toxicol (Phila). 2019;57(2):99-103. PubMed 30073844
- Yuen MF, Ip P, Ng WK, Lai CL. Hepatotoxicity due to a formulation of Ganoderma lucidum (lingzhi). J Hepatol. 2004;41(4):686-687. PubMed 15464254
- Wanmuang H, Leopairut J, Kositchaiwat C, Wananukul W, Bunyaratvej S. Fatal fulminant hepatitis associated with Ganoderma lucidum (Lingzhi) mushroom powder. J Med Assoc Thai. 2007;90(1):179-181. PubMed 17621752
- Kwon O, Kim Y, Paek JH, et al. Chaga mushroom-induced oxalate nephropathy that clinically manifested as nephrotic syndrome: a case report. Medicine (Baltimore). 2022;101(10):e28997. PubMed 35451393
- Nguyen AH, Gonzaga MI, Lim VM, Adler MJ, Mitkov MV, Cappel MA. Clinical features of shiitake dermatitis: a systematic review. Int J Dermatol. 2017;56(6):610-616. PubMed 28054338
- NHS. Breastfeeding and medicines. nhs.uk
- NHS. Vitamins for children. nhs.uk