By SterlingMedicalCenter.org Editorial Team. Sources checked October 3, 2026. SterlingMedicalCenter.org is an independent editorial publication, not a medical practice or healthcare provider. This article is for education and is not medical advice.
The Short Answer
If you take a mushroom supplement every day, the sources we reviewed do not establish what months or years of use will do. Operation Supplement Safety, a U.S. Department of Defense program that reviews dietary supplement research for service members, says there is limited information supporting the safety of functional mushrooms in supplements. It also says product quality and purity can vary widely.
The side effects it lists are mostly mild: nausea, vomiting, diarrhea, stomach discomfort, dry mouth, and allergic reactions. The more serious concern is rare. There are published case reports of liver injury linked to reishi products. Case reports cannot show how often this happens, but they are a good reason to know the warning signs and to track how you feel.
Below are a simple monitoring log, a list of “stop and call” signs, and a guide to who should talk to a clinician before starting.
What Is Known and What Is Not
Functional mushroom supplements usually contain species such as lion's mane, turkey tail, reishi, cordyceps, shiitake, chaga, and maitake, sold as powders or extracts. According to Operation Supplement Safety, it is also unclear whether a supplement delivers the same compounds or effects as eating whole mushrooms.
The same source notes that some products combine several mushrooms in a proprietary blend, and there is little to no safety data on how those combinations behave together. A multi-mushroom label therefore tells you less about long-term safety than you might expect.
Digestive, Skin, and Allergy Effects
For a daily supplement, the practical question is whether these effects fade, stay the same, or get worse over time. A log helps you answer that.
An allergic reaction can range from itching or a rash to a medical emergency. Swelling of the face, lips, or throat, or trouble breathing, needs emergency care right away.
Liver Injury: Rare, but Reported
Published case reports describe liver injury in people using reishi (Ganoderma lucidum or lingzhi) products:
- A 2023 report in Cureus described a 47-year-old man with fatty liver disease who took several tablespoons of reishi powder over three days while drinking a large amount of alcohol. His liver enzymes were sharply elevated, and they had returned to normal at a two-week follow-up. The authors considered the powder the likely cause, possibly worsened by alcohol, and noted that product instructions do not address alcohol. Read the report.
- The same paper recounts an earlier report of fatal fulminant hepatitis in a patient who switched from boiled reishi to reishi powder.
- A 2022 report in AME Medical Journal described a 19-year-old man who drank a premixed reishi coffee for about a year. He developed jaundice, tea-colored urine, and pale stools, and his liver tests gradually normalized after he stopped. The authors attributed the injury to the product but noted he also had liver scarring from a past hepatitis B infection, which may have made him more susceptible. Read the report.
Limits: These are individual cases, and some involved alcohol or existing liver conditions. They do not show how common liver injury is, and the cases we reviewed all involve reishi, so they say little about other mushrooms in either direction.
Do Not Confuse These With Psilocybin or “Magic Mushroom” Products
Searches for “mushroom side effects long-term” often return pages about psilocybin, the psychoactive compound in “magic mushrooms.” That is a different category. GoodRx reports that the clinical studies it reviewed found no serious long-term side effects of psilocybin, while noting that trials often exclude people with certain mental health conditions. It also describes short-term risks such as distressing hallucinations and advises supervised medical settings. None of this applies to reishi, lion's mane, or other functional mushroom supplements.
Operation Supplement Safety also warns about products marketed with “legal high” language. It says some may contain prohibited or harmful substances, including Amanita muscaria compounds or psilocybin, and that such ingredients can cause vomiting, confusion, loss of consciousness, and seizures. A product that promises a “buzz” or “trip” is not a functional mushroom supplement.
Your Long-Term Monitoring Log
This log is an editorial tool, not a validated clinical instrument. Its value is that it gives you and your clinician something concrete to look at. Write down the start date, the product and serving, and any other supplements and medicines you take, then check in weekly for the first month and monthly after that.
- Digestive symptoms: nausea, vomiting, diarrhea, stomach pain. Note how often, how severe, and whether it is getting better or worse.
- Skin reactions: itching, rash, hives. Note when they started relative to a dose.
- Bruising or bleeding: new or unexplained bruises, nosebleeds, or bleeding that is slow to stop.
- Energy: unusual tiredness that is new or growing.
- Liver-related signs: yellowing of the skin or eyes, dark urine, pale stools, itching, persistent nausea or vomiting, pain in the upper abdomen.
- Alcohol and other supplements: note any change, since the case reports involved alcohol or other conditions.
Stop and Call Triggers
These are general safety guidelines, not a diagnosis.
- Call emergency services: trouble breathing, or swelling of the face, lips, or throat.
- Stop the supplement and contact a clinician promptly: yellowing of the skin or eyes, dark urine, pale stools, persistent vomiting, abdominal pain, or unexplained severe fatigue.
- Stop and call during business hours: a new rash or itching, diarrhea that does not settle, or unexplained bruising or bleeding.
- Bring your log and the product label to the appointment, including the full ingredient list.
Who Should Check With a Doctor First
- Anyone with liver disease or past liver problems, or who drinks alcohol regularly: the serious case reports we reviewed involve the liver, and alcohol or existing liver conditions were a factor in two of the three.
- Anyone taking blood thinners, diabetes medicines, or immune-suppressing drugs: our functional mushroom supplement safety guide discusses these interactions.
- Anyone pregnant, nursing, or giving a supplement to a child: because safety information is limited, ask first.
- Anyone with a known mushroom or mold allergy: allergic reactions are a reported side effect.
- Anyone with surgery coming up: tell your surgical team about every supplement you take.
- Anyone taking many supplements at once: it is harder to tell which one is causing a problem.
What You Can Do Next
- Show your clinician or pharmacist the exact product label before you start, or now if you already have.
- Ask whether baseline or follow-up liver blood tests make sense for you. The sources we reviewed do not set a testing schedule for mushroom supplements, so this is a conversation, not a rule.
- Avoid adding new supplements at the same time, so any reaction is easier to trace.
- Choose products with a clear ingredient list, and be wary of proprietary blends and “legal high” marketing.
- Keep the log going, and stop the product if a trigger above appears.
Limits of This Article
This article draws on published case reports and a government safety summary written for service members. It cannot tell you your personal risk, and it does not cover every mushroom species or product. Nothing here replaces advice from a clinician who knows your health history.
Sources
- Operation Supplement Safety, “Mushroom Dietary Supplements,” posted April 2, 2026: opss.org
- Guedikian R, et al. “Ganoderma lingzhi (Reishi Mushroom)-Induced Acute Liver Injury in the Setting of Alcohol Use.” Cureus, 2023: PMC10599861
- Tay YZ, Pan AF, Chiam KH. “Cholestatic liver injury from Ganoderma lucidum coffee extract: a case report.” AME Medical Journal, 2022;7:29: amj.amegroups.org
- GoodRx, “What Are the Side Effects of Magic Mushrooms (Shrooms)?” updated August 12, 2024: goodrx.com
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