Quick answer
NIH's LiverTox rates reishi a possible rare cause of clinically apparent liver injury (category D), based on a few reports from China, Japan, Thailand and India, one fatal. Liver enzymes did not change in short placebo-controlled trials. Ask your doctor first if you have liver disease or have had a liver reaction to reishi.1
Key facts
- LiverTox rates reishi a possible rare cause of clinically apparent liver injury (category D) and concludes that, given its worldwide use, such injury must be extremely rare.1
- In the reported cases, symptoms began usually 1 to 2 months after starting, and included fatigue, nausea, abdominal pain, poor appetite, dark urine and yellowing of the skin and eyes.1
- Most people recovered within 1 to 3 months of stopping and no chronic injury has been reported, but one woman died.1
- Two of the best-known cases began after a switch from boiled reishi to reishi powder, and both patients had also taken other therapeutic agents.1,2
- In small, short placebo-controlled trials in healthy adults, liver enzymes and other liver and kidney tests did not change.1,3,4
What NIH's liver injury database says
LiverTox, the NIH database of liver injury from medicines and supplements, has a chapter on reishi, also called lingzhi. It says reishi is well tolerated and has not been associated with raised serum liver enzymes during treatment, but that it has been implicated in rare single instances of acute liver injury, though in most reports other diagnoses were not adequately excluded.1
LiverTox rates reishi a possible rare cause of liver injury (category D) and notes that many reported cases were poorly documented, with other causes not always ruled out.1
LiverTox concludes that, in view of the extensive worldwide use of reishi, clinically apparent liver injury from it must be extremely rare.1
What the reported cases looked like
Rare cases of liver injury have been reported, usually 1 to 2 months after starting reishi, with tiredness, nausea, stomach pain, poor appetite, dark urine or yellowing of the skin and eyes. Most people recovered within 1 to 3 months of stopping, but one woman died.1
Two of the best-known reports share a pattern. A woman in Hong Kong and a woman in Thailand each developed liver injury 1 to 2 months after switching from boiled reishi to reishi powder, and both had also taken other therapeutic agents. The Thai woman died, and the Hong Kong woman improved slowly after stopping.1,2
A different pattern was reported in Japan in 2021. A 61-year-old man taking a commercial reishi product developed liver nodules, a high eosinophil count and slightly raised liver enzymes, and all of these resolved after he stopped it.5
What controlled trials measured
In 18 healthy adults who took 1.44 g of a reishi preparation a day for 4 weeks, tests showed no sign of liver, kidney or DNA harm. In 16 healthy volunteers given 2 g of reishi extract twice a day for 10 days, there were no adverse effects compared with placebo. In 157 adults who took 200 mg a day of a purified reishi beta-glucan for 12 weeks, kidney and liver blood tests did not change.3,4,6
A Cochrane review of five trials in 398 adults under medical care, using 1.4 to 3 g a day for 12 to 16 weeks, found side effects somewhat more common with reishi than with placebo, though none was serious.7
The trials in healthy adults ran from 10 days to 12 weeks and enrolled 16 to 157 people each. That is too few people, for too short a time, to find an event that LiverTox calls extremely rare, so the trials neither show nor rule out the cases above.1,3,4
The product and everything else a person takes
When 19 reishi supplements bought in the United States were analyzed, the measured triterpenes and polysaccharides matched the label in only 5.8
LiverTox notes that in some of the reports, other common causes of liver injury were not excluded, among them other herbal products and contaminants of the herbal product. A reishi supplement is often one of several products a person takes, and the sources cannot say which one a liver problem came from.1
Signs LiverTox lists
- Fatigue, nausea, abdominal pain and poor appetite.1
- Dark urine.1
- Yellowing of the skin and eyes, called jaundice.1
In the published cases LiverTox describes, recovery was rapid once the product was stopped and was complete within 1 to 3 months, with or without steroid treatment. People who notice these signs can contact a doctor and show them the product.1
Who should ask a doctor or pharmacist first
- Anyone who has liver disease, since liver injury is the concern LiverTox describes.1
- Anyone who has had a liver reaction to reishi before.1
- Anyone who takes several herbal products or medicines, because a pharmacist can look at all of them together when a liver test is abnormal.1
- Anyone who is allergic to mushrooms or molds.
This page reports what the sources say. It does not tell any person whether to take reishi.
Questions people ask
Can reishi tea hurt your liver?
LiverTox does not single out tea. In two published cases the liver injury began after a switch from boiled reishi to powder, and both patients had tolerated the boiled form. Ask your doctor or pharmacist about the form you use.1,2
How soon after starting reishi does liver injury appear?
In LiverTox's account of the reported cases, usually 1 to 2 months after starting, with a range from a few days to 6 months.1
Does reishi raise liver enzymes?
LiverTox says serum liver enzymes did not change during treatment in multiple small, short placebo-controlled trials. The injury it describes was rare and was found in individual case reports.1
Is reishi liver damage reversible?
In the published cases LiverTox describes, recovery was rapid after stopping and complete within 1 to 3 months, and no chronic injury has been reported. One woman died, so the reported cases were not all mild.1
Is reishi bad for your liver?
LiverTox rates reishi a possible rare cause of liver injury, not a likely one, and says many reported cases were poorly documented. Anyone with liver disease can ask a doctor first, since liver injury is the concern.1
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Sources
- LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Lingzhi, Reishi. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases. Last update October 5, 2024. Opened 2026-10-07.
- 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. Opened 2026-10-11.
- Wicks SM, Tong R, Wang CZ, O'Connor M, Karrison T, Li S, Moss J, Yuan CS. Safety and tolerability of Ganoderma lucidum in healthy subjects: a double-blind randomized placebo-controlled trial. Am J Chin Med. 2007;35(3):407-414. Opened 2026-10-07.
- Chen SN, Nan FH, Liu MW, Yang MF, Chang YC, Chen S. Evaluation of Immune Modulation by β-1,3; 1,6 D-Glucan Derived from Ganoderma lucidum in Healthy Adult Volunteers, A Randomized Controlled Trial. Foods. 2023;12(3):659. Opened 2026-10-07.
- Kogure T, Koiwai A, Fukushi D, Satoh M, Murakami K, Hirota M, Endo K, Murakami K, Satoh K. Hypereosinophilia with hepatic nodule formation caused by Ganoderma lucidum. Intern Med. 2021;60(24):3897-3903. Opened 2026-10-11.
- Wachtel-Galor S, Tomlinson B, Benzie IF. Ganoderma lucidum ("Lingzhi"), a Chinese medicinal mushroom: biomarker responses in a controlled human supplementation study. Br J Nutr. 2004;91(2):263-269. Opened 2026-10-07.
- Klupp NL, Chang D, Hawke F, Kiat H, Cao H, Grant SJ, Bensoussan A. Ganoderma lucidum mushroom for the treatment of cardiovascular risk factors. Cochrane Database Syst Rev. 2015;(2):CD007259. Opened 2026-10-07.
- Wu DT, Deng Y, Chen LX, Zhao J, Bzhelyansky A, Li SP. Evaluation on quality consistency of Ganoderma lucidum dietary supplements collected in the United States. Sci Rep. 2017;7(1):7792. Opened 2026-10-07.
This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.