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Reishi mushroom benefits are mostly a story of long tradition and promising lab work, with human trials that have so far been small and largely disappointing. Reishi, also called lingzhi, has been used in East Asian medicine for centuries and is now sold as capsules, powders, teas and coffee blends. Two Cochrane reviews found weak evidence for the uses people ask about most, and reishi carries real cautions: rare liver injury reports and possible bleeding concerns with blood thinners. Here is what reishi is, what the research shows and who should be careful.
Peptide Labs sells no reishi products, and this article does not recommend any product. It is general information, not medical advice.
Key Takeaways
- Reishi (Ganoderma lucidum, also called lingzhi) is a fan-shaped, reddish-brown mushroom used in traditional Chinese medicine.
- A Cochrane review of five trials found no meaningful effect on blood sugar, cholesterol or blood pressure.
- A Cochrane review in people with cancer found low-quality trials and no evidence for reishi on its own.
- Rare cases of serious liver injury have been linked to reishi powder, including one death.
- Reishi may add to bleeding risk with warfarin and similar drugs; tell your pharmacist and surgeon.
What is reishi mushroom?
The NIH LiverTox database describes lingzhi, usually Ganoderma lucidum when sold as reishi, as a large, reddish-brown mushroom with a distinctive fan shape, used in traditional Chinese medicine to improve health and restore vitality. A Cochrane review notes it has been consumed in Asia for more than 2,000 years. It was traditionally boiled into a tea, and today it is mostly sold as capsules, ground powder and tea made from dried fruiting bodies, as well as spore products and extracts.
Researchers have focused on reishi’s polysaccharides, complex carbohydrates that act on immune cells in lab studies. Lab and animal findings do not tell you what happens when a person swallows a capsule, which is why human trials matter. Reishi is also a common ingredient in mushroom blends; our guide to mushroom coffee covers those products and how they compare with regular coffee.
Reishi mushroom benefits: what the research shows
Human trials of reishi are few, and their quality varies. The table summarizes the strongest evidence we found.
| Area studied | What the research found | Evidence quality |
|---|---|---|
| Blood sugar, cholesterol and blood pressure | Cochrane 2015: five trials, 398 people, no meaningful effect | Small trials, mostly unclear risk of bias |
| Metabolic syndrome with diabetes | 2016 trial of 84 adults: no effect on any measured outcome over 16 weeks | One randomized, placebo-controlled trial |
| People with cancer | Cochrane 2016: five trials; some signals as an add-on, none on its own | Low; no trial measured long-term survival |
| Immune markers | Small shifts in immune cell counts in cancer trials | Low; lab markers, not health outcomes |
Heart and metabolic health
A 2015 Cochrane review pooled five trials with 398 participants testing reishi for heart disease risk factors. It found no statistically or clinically significant change in HbA1c, total or LDL cholesterol, body mass index, blood pressure or triglycerides, and concluded that the evidence does not support reishi for cardiovascular risk factors in people with type 2 diabetes. A 2016 double-blind trial in 84 Australian adults with type 2 diabetes and metabolic syndrome compared reishi, reishi with cordyceps, and placebo for 16 weeks and found no effect on blood sugar or any other measured outcome.
Cancer research
Reishi is popular among people with cancer, especially in Asia. A 2016 Cochrane review found five randomized trials, all of generally poor methodological quality. When reishi was added to chemotherapy or radiotherapy, tumors were somewhat more likely to respond, and some immune cell counts rose, but reishi alone did not show the same response, and no trial tracked long-term survival. The reviewers found insufficient evidence to justify reishi as a first-line option. Anyone in cancer care should talk with their oncology team before taking it, partly because of the interaction and lab test issues below.
Sleep, stress and immunity claims
Marketing often links reishi with calm, sleep and immune support. These ideas come mainly from traditional use and laboratory studies. We did not find large, high-quality human trials showing that reishi improves sleep, stress or resistance to infection, so consider such label language unproven.
Reishi side effects and liver safety
In trials, reishi side effects have usually been mild. Memorial Sloan Kettering Cancer Center (MSKCC) lists nausea and insomnia among them, and the 2015 Cochrane review found more adverse events with reishi than placebo, though none were serious. The bigger concern is rare liver injury.
- Case reports: a 2004 report from Hong Kong and a 2007 report from Thailand linked reishi powder to hepatitis; the Thai case was fatal. Both patients had used boiled reishi without problems before switching to powder for one to two months.
- A 2023 US case: a 47-year-old man developed acute hepatitis after taking reishi powder while drinking heavily. His liver tests returned to normal within two weeks after stopping.
- The LiverTox view: NIH’s liver injury database calls reishi well tolerated and not linked to liver enzyme rises in studies, but implicated in rare single cases of acute liver injury, noting that other causes were often not ruled out.
Stop reishi and contact a clinician promptly if you notice signs of liver trouble such as yellowing of the skin or eyes, dark urine, unusual fatigue or pain in the upper right abdomen. If you drink alcohol heavily or already have liver disease, ask your doctor before using any concentrated herbal powder. Our guides to turmeric side effects and ashwagandha describe similar rare liver reports with other popular herbs, and liver cleanse supplements explains why no supplement needs to clean your liver.
Reishi with warfarin and other medicines
MSKCC advises that reishi may increase bleeding risk when combined with blood thinners such as warfarin, and that reishi extracts may prolong clotting times on lab tests. Evidence is mixed: a small 2005 trial in 40 healthy volunteers found no impairment of clotting or platelet function after four weeks of reishi. Because people on anticoagulants are not healthy volunteers, the cautious approach is to involve your prescriber before combining them and to tell your surgeon before any procedure.
- Immunosuppressants: MSKCC says to talk with your provider if you take drugs that suppress the immune system, such as those used after an organ transplant.
- Drug-processing enzymes: lab studies suggest reishi may affect liver enzymes that break down medicines, though the real-world importance is unknown.
- Lab tests: MSKCC notes that reishi spore powder may raise CA72-4, a blood marker used in cancer monitoring, which could cause confusion if your care team does not know you take it.
- Pregnancy and breastfeeding: safety has not been established in human studies, so avoid concentrated reishi products unless your clinician agrees.
How to choose and read a reishi label
Reishi products vary widely. Some use ground whole mushroom, others hot-water or alcohol extracts, and others spores or spore oil, and the case reports above involved powders. A clear label names the species (Ganoderma lucidum or Ganoderma lingzhi), the part used and whether it is an extract, and shows a full Supplement Facts panel. Claims that reishi fights cancer or boosts immunity against specific illnesses are not supported and are not allowed on supplement labels.
Independent testing helps confirm identity and screen for contaminants; see our guide to third-party tested supplements. For another heavily hyped ingredient whose evidence lags its marketing, read our NMN supplement guide.
Frequently Asked Questions
What are the main reishi mushroom benefits?
Reishi has a long traditional history, but human trials are small. Cochrane reviews found no meaningful effect on blood sugar, cholesterol or blood pressure and only low-quality evidence in people with cancer.
What are reishi side effects?
Reported side effects include nausea and insomnia. Rare cases of serious liver injury have been linked to reishi powder, and it may add to bleeding risk with blood thinners.
Is reishi the same as lingzhi?
Yes. Lingzhi is the Chinese name. Products sold as reishi are usually Ganoderma lucidum, and some are labeled Ganoderma lingzhi.
Can I take reishi with warfarin?
Talk to your prescriber first. MSKCC warns reishi may increase bleeding risk with blood thinners, even though one small study in healthy people found no clotting changes.
Is reishi safe for the liver?
Most people in studies had no liver problems, but rare cases of acute hepatitis, one fatal, have been reported with reishi powder. Stop and see a clinician if you notice yellow skin or dark urine.
Does reishi help you sleep?
That claim comes mainly from tradition and lab studies. We found no large, high-quality human trials showing reishi improves sleep.
Questions about a label? Contact us or read our Buyer’s Guide. Follow the label and ask a healthcare provider before starting any supplement, especially if you take medicines or are pregnant. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Last reviewed October 2026.
Related guides: Mushroom Coffee: Benefits, Caffeine and Is It Healthy?, Ashwagandha Benefits, Side Effects and Safety: What Studies Show, Holy Basil (Tulsi): Benefits, Research and Side Effects, Chaga Mushroom: Benefits, Kidney Risks and Warfarin, Cordyceps Benefits: Research, Side Effects and Militaris vs Sinensis.