Reishi
Reishi (Ganoderma lucidum and related lingzhi species) in plain language. Liver injury reports and bleeding cautions first, then what trials found and the species naming dispute.
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.
Safety first. Liver injury has been reported with reishi, mostly with powdered products, and one report was fatal. [1][2] Anyone with liver disease, or symptoms of liver trouble, should speak to a clinician before using reishi; the liver safety page lists warning signs. Memorial Sloan Kettering Cancer Center (MSK) also advises talking to a healthcare provider if you take warfarin (reishi may raise bleeding risk) or immunosuppressants, and before any reishi spore powder. [1] See liver safety and supplements and medicine interactions.
Traditional use
Traditional use only, not proof. The NCI summary says Ganoderma has a long history in East Asia, appearing in the Chinese materia medica "Shen Nung Ben Cao Jing" written between 206 BC and 8 AD, where it was considered a tonic for prolonging life. [3] It is called Ling Zhi in traditional Chinese medicine and Reishi in Japan. [3] Tradition does not show that a supplement works, and research is not dismissed because a use is traditional.What research shows
| Question | What the source found | Strength of evidence | Population and form |
|---|---|---|---|
| Cancer treatment | A Cochrane review of 5 randomized trials found not enough evidence to justify use as first-line cancer treatment; trial quality was generally unsatisfying. [6] | Insufficient evidence | People with cancer; various G. lucidum products |
| Immune markers in cancer | In that review, some immune cell percentages rose slightly. [6] | Biomarker only; not a clinical outcome | Cancer patients |
| Blood sugar, cholesterol, blood pressure | A Cochrane review of 5 trials (398 people; the three trials used in the analysis were all in people with type 2 diabetes) found no significant change in HbA1c, LDL, total cholesterol or blood pressure; it did not support use. [7] | No good evidence of benefit | Adults with type 2 diabetes |
| Fatigue | A 132-person trial of a polysaccharide extract over 8 weeks found lower fatigue scores than placebo in people with neurasthenia in China. [8] | Promising but limited | Extract; 8 weeks |
| Sleep | Proper evidence not found. We searched PubMed for human trials of Ganoderma with sleep or insomnia and found none usable. | Insufficient evidence | Not applicable |
| Alzheimer's disease | MSK reports a pilot of reishi spore powder that did not find it helpful. [1] | No good evidence of benefit | Spore powder, pilot |
Immune "boosting" is a marketing phrase. Reishi showed immune effects in lab work and small studies, but higher test values are not the same as fewer infections. See reishi and the immune system and reishi for sleep and stress.
Quality
Products made from mycelium grown on grain can contain large amounts of alpha-glucans from the grain, unlike fruiting body extracts, which are entirely beta-glucan, according to the NCI summary. [3] See mycelium on grain, reishi side effects and liver reports and quality testing.Official statements
NCI (PDQ, updated 2024): the US FDA has not approved medicinal mushrooms as a treatment for cancer or any other medical condition. [3]Frequently asked questions
Is reishi safe for the liver?
Not guaranteed. Case reports, including one fatal case with powder, link reishi to liver injury. [1][2] Anyone with liver disease should ask a clinician first.
Is "lingzhi" the same as reishi?
Usually the names refer to the same traditional mushrooms, but which species a product contains is disputed. [3][4]
Can reishi replace cancer treatment?
No. A Cochrane review found insufficient evidence for use as a first-line cancer treatment. [6] Tell the oncology team about any product.
Does reishi help sleep or stress?
Proper evidence not found for sleep in the sources we searched. MSK lists insomnia as a reported side effect. [1] See reishi tea, powder and coffee for product differences.
Can I take reishi with blood thinners?
MSK advises asking your healthcare provider because bleeding risk may rise. [1] See reishi and medicines.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
What it is, and the naming dispute
Wild mushrooms cannot be safely identified from a description, so this guide gives no identification help. If someone eats an unknown wild mushroom, call Poison Help at 1-800-222-1222 (US) or 911 for collapse or seizure. See poison help by country.
Safety in more detail
- Liver: a 2007 Thai report described fatal fulminant hepatitis after powder, in a person who had taken boiled reishi earlier without harm and was also on other medicines. [2] A 2023 case report described acute hepatitis after reishi powder together with alcohol that fully resolved in two weeks. [9]
- Bleeding and surgery: MSK lists a bleeding-risk interaction with anticoagulants and antiplatelets, and says extracts may prolong clotting tests. [1] In contrast, a controlled trial in 40 healthy volunteers (20 on 1.5 g daily for 4 weeks) found no change in clotting measures. [10] Mixed evidence: tell the surgical team and your prescriber.
- Immune medicines and autoimmune conditions: MSK says reishi may enhance immune response and may trigger or worsen autoimmune skin disease, though cause is not established. [1]
- Other medicines: in the lab, reishi polysaccharides inhibited enzymes that clear some drugs; MSK says the clinical relevance is not known. [1]
- Tests: reishi spore powder raised a tumor marker (CA72-4) and may confuse cancer test results. [1]
- Children: MSK describes acute neurotoxicity in a 9-year-old after several fungal supplements, including reishi, that resolved after stopping. [1]
- Pregnancy and breastfeeding: not described in the sources we read. See pregnancy and breastfeeding.
- Short-term tolerance: in 16 healthy volunteers, no adverse effects were seen over 10 days. [11] This does not show long-term safety.
- Common effects: nausea and insomnia were reported. [1]
References
- Memorial Sloan Kettering Cancer Center, Reishi Mushroom, About Herbs Read 2026-10-23.
- Fatal fulminant hepatitis associated with Ganoderma lucidum (Lingzhi) mushroom powder. J Med Assoc Thai 2007 Read 2026-10-23.
- National Cancer Institute, Medicinal Mushrooms (PDQ), Health Professional Version, updated November 6, 2024 Read 2026-10-23.
- GBIF Backbone Taxonomy, Ganoderma lucidum and Ganoderma sichuanense Read 2026-10-23.
- Global diversity of the Ganoderma lucidum complex (Ganodermataceae, Polyporales) inferred from morphology and multilocus phylogeny. Phytochemistry 2015 Read 2026-10-23.
- Jin X et al. Ganoderma lucidum (Reishi mushroom) for cancer treatment. Cochrane Database Syst Rev 2016 Read 2026-10-23.
- Klupp NL et al. Ganoderma lucidum mushroom for the treatment of cardiovascular risk factors. Cochrane Database Syst Rev 2015 Read 2026-10-23.
- A randomized, double-blind and placebo-controlled study of a Ganoderma lucidum polysaccharide extract in neurasthenia. J Med Food 2005 Read 2026-10-23.
- Ganoderma lingzhi (Reishi Mushroom)-Induced Acute Liver Injury in the Setting of Alcohol Use: A Case Report. Cureus 2023 Read 2026-10-23.
- A prospective, randomized, double-blind, placebo-controlled study of the platelet and global hemostatic effects of Ganoderma lucidum (Ling-Zhi) in healthy volunteers. Anesth Analg 2005 Read 2026-10-23.
- Safety and tolerability of Ganoderma lucidum in healthy subjects: a double-blind randomized placebo-controlled trial. Am J Chin Med 2007 Read 2026-10-23.