Mushroom Safety Quick Reference: Warning Signs and Whom to Call
A one-page safety reference for mushrooms: what to do first if someone ate a wild mushroom, warning signs after a mushroom product or meal, and whom to call. US numbers only.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
If someone may have eaten a wild or unknown mushroom, call Poison Help now at 1-800-222-1222 (US). If the person collapses, has a seizure, has trouble breathing or cannot be awakened, call 911. [1] You can also use the online tool at poison.org. [1]
You do not need to be sure it is an emergency to call: the Poison Help line is free and confidential, and an official medical encyclopedia states that a call does not need to be an emergency. [2] Follow whatever the poison center tells you, including what to do about any sample. Outside the US, see Poison Help by Country.
This page is a quick reference, not a diagnosis tool. It gives no way to identify mushrooms. Identification apps tested in one study were not reliable enough to exclude poisonous mushrooms. [3] For the full steps, see Plant and Mushroom Poisoning and Mushroom Poisoning: Warning Signs and Urgent Help.
Wild mushrooms: three facts that matter
- Photos and apps are not enough. In a study of three popular identification apps, the apps were not reliable enough to exclude poisonous mushrooms when used alone. [3]
- Cooking and drying do not make a poisonous mushroom safe. No matter how much you cook or dry them, you will not destroy their toxins. [4]
- Only an expert can tell poisonous from edible. [4] This site gives no identification, foraging or look-alike guidance.
Warning signs after a mushroom product or meal
The table lists signs that sources linked to specific mushrooms. A sign here does not prove the mushroom is the cause. If any of these happen, contact a clinician or pharmacist, and tell them every product you take. For signs of a severe allergic reaction, see the first row.
| Situation | What the sources describe | What to do |
|---|---|---|
| Hives, swelling of lips or face, wheezing, trouble breathing | NHS lists itchy skin or a raised rash (hives), swelling of the lips, face and eyes (angioedema) as signs of food allergy, and says serious signs may need immediate treatment in hospital. [5] A case report describes anaphylaxis after breathing oyster mushroom spores on a farm. [6] | Call 911 (US) for trouble breathing or collapse. [1] See Severe Allergic Reactions to Natural Products. |
| Rash after eating shiitake | A French poison-center review concluded inadequate cooking seems to be a driver of shiitake dermatitis. [7] A systematic review found 22% of cases followed lightly cooked or undercooked mushrooms. [8] | Contact a clinician. Cooking food through is covered in Cooking Edible Mushrooms Safely. |
| Cough or breathing problems after exposure to spores | A cancer center lists pneumonia caused by hypersensitivity to spores among shiitake side effects. [9] | Seek medical care for breathing trouble. |
| Possible liver problem on a mushroom supplement | Liver injury is listed as a reishi side effect, with a fatal case report after powdered reishi. [10] Three advanced cancer patients had severe hepatic damage while taking Agaricus blazei extract, and two died. [11] | Contact a clinician promptly. See Liver Injury Warning Signs From Supplements and Herbs. |
| Kidney problems with chaga powder | Case reports describe oxalate nephropathy after ingesting chaga powder. [12] | Tell a clinician about chaga use, especially with kidney disease. See Mushrooms and the Kidneys, Oxalates and the Liver. |
| Unusual bleeding or bruising | Reishi, cordyceps, maitake and chaga summaries each say the mushroom may increase bleeding risk. [10] [13] [14] [12] One case report described excessive bleeding after a tooth extraction in someone using cordyceps daily. [13] | Tell your clinician, dentist and surgical team before any procedure. See Supplements Before Surgery. |
| Fever, aches or stomach upset after eating enoki | FDA and CDC investigated a Listeria outbreak linked to enoki. [15] NHS lists people who are pregnant or have a weakened immune system as higher-risk groups for listeriosis. [16] | Contact a clinician and mention the mushrooms. Cook enoki thoroughly if you are pregnant, 65 or older, or immunocompromised. [15] |
Before you take a mushroom supplement
- Tell your care team. Dietary supplements may interact with medicines or pose risks with certain medical problems or before surgery. [17]
- Cancer care. Reishi spore powder was found to raise the tumor marker CA72-4, which can show up on test results. [10] Tell the oncology team about any mushroom product.
- Blood thinners or blood sugar medicines. Reishi: ask first if you take blood thinners or immunosuppressants. [10] Cordyceps: ask first about insulin or other blood sugar medicines. [13]
- Pregnancy, breastfeeding and children. Many dietary supplements have not been tested in pregnant women, nursing mothers or children. [17]
- The label may not match the product. What is on the label may not be what is in the product. [17] In a Thai online survey, 54.3% of cordyceps products were falsified. [18]
- Report problems. See Side Effects, Allergic Reactions and Reporting.
Whom to call
| Who | When |
|---|---|
| 911 (US) | Collapse, seizure, trouble breathing or cannot be awakened. [1] |
| Poison Help 1-800-222-1222 (US) | Any exposure to a wild or unknown mushroom, or a poisoning question; free and confidential. [1] [2] |
| Your pharmacist or prescriber | Before combining a mushroom product with medicines; never stop a prescribed medicine on your own. |
| Your clinician | A rash, liver, kidney or bleeding concern, or any reaction after a mushroom product. |
| Your oncology or surgical team | Before or during treatment or an operation. |
Frequently asked questions
What should I do first if a child ate part of a wild mushroom?
Call Poison Help at 1-800-222-1222 (US). [1] Call 911 if the child collapses, has a seizure, has trouble breathing or cannot be awakened. [1] See Mushroom, Plant and Berry Ingestions: Urgent Steps.
Can cooking make a wild mushroom safe?
No. No matter how much you cook or dry them, you will not destroy their toxins. [4]
Can an app confirm that a mushroom is safe?
No. In a study, three popular identification apps were not reliable enough to exclude poisonous mushrooms when used alone. [3]
Do I have to wait until I feel sick before calling?
No. The Poison Help line does not need an emergency to be called, and the service is free and confidential. [2] A poison center can tell you what to do next.
Where do I find the number outside the United States?
See Poison Help by Country. We do not list other countries' numbers on this page.
References
- Poison Control (America's Poison Centers). Poison Control home page. Help line 1-800-222-1222. Read 2026-10-23.
- MedlinePlus Medical Encyclopedia. Jerusalem cherry poisoning. Used only for its description of the national Poison Help line. Read 2026-10-23.
- Hodgson SE, McKenzie C, May TW, Greene SL. A comparison of the accuracy of mushroom identification applications using digital photographs. Clin Toxicol (Phila). 2023. PubMed 36794335. Read 2026-10-23.
- Penn State Extension. Preparing and Preserving Mushrooms. Read 2026-10-23.
- NHS. Food allergy. UK page; the emergency number it gives is for the UK. Read 2026-10-23.
- Branicka O, Rozlucka L, Gawlik R. A case of anaphylactic reaction following oyster mushroom (Pleurotus ostreatus) inhalation. Int J Occup Med Environ Health. 2021. PubMed 33630827. Read 2026-10-23.
- Boels D, et al. Shiitake dermatitis: experience of the Poison Control Centre Network in France from 2014 to 2019. Clin Toxicol (Phila). 2022. PubMed 35404185. Read 2026-10-23.
- Nguyen AH, et al. Clinical features of shiitake dermatitis: a systematic review. Int J Dermatol. 2017. PubMed 28054338. Read 2026-10-23.
- Memorial Sloan Kettering Cancer Center. Shiitake Mushroom. About Herbs, Botanicals and Other Products. Read 2026-10-23.
- Memorial Sloan Kettering Cancer Center. Reishi Mushroom. About Herbs, Botanicals and Other Products. Read 2026-10-23.
- Mukai H, Watanabe T, Ando M, Katsumata N. An alternative medicine, Agaricus blazei, may have induced severe hepatic dysfunction in cancer patients. Jpn J Clin Oncol. 2006. PubMed 17105737. Read 2026-10-23.
- Memorial Sloan Kettering Cancer Center. Chaga Mushroom. About Herbs, Botanicals and Other Products. Read 2026-10-23.
- Memorial Sloan Kettering Cancer Center. Cordyceps. About Herbs, Botanicals and Other Products. Read 2026-10-23.
- Memorial Sloan Kettering Cancer Center. Maitake. About Herbs, Botanicals and Other Products. Read 2026-10-23.
- U.S. Food and Drug Administration. Outbreak Investigation of Listeria monocytogenes: Enoki Mushrooms (November 2022). Read 2026-10-23.
- NHS. Listeriosis. Read 2026-10-23.
- National Center for Complementary and Integrative Health. Using Dietary Supplements Wisely. Read 2026-10-23.
- Wirasathien L, Sriputhon N, Tangkiatkumjai M. Post-marketing surveillance of cordyceps products online: identifying falsified products and regulatory challenges. BMC Complement Med Ther. 2026. PubMed 41947147. Read 2026-10-23.