← Back

Research · Supplements

Reishi

A Cochrane review of 5 cancer trials found better tumor response alongside chemotherapy or radiotherapy, with poor trial quality and no survival data. Two meta-analyses, including a Cochrane review in type 2 diabetes, found no change in blood sugar, cholesterol or blood pressure. Case reports describe acute liver injury, eosinophil liver nodules and a falsely raised tumor marker.

Add to Bio HackChecked 2026-11-09
Status
Dietary supplement in the US. Not approved by the FDA as a drug for any use.
Also called
Ganoderma lucidum, lingzhi, ling zhi, Ganoderma lingzhi, mushroom of immortality, reishi mushroom, Ganoderma spore powder, ganoderic acids
Taken for
immunity, cancer support, stress, sleep, energy, fatigue, blood sugar, cholesterol, longevity, liver health

Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on

What people take it for, and what was found

Shown to help1

LimitedStudied in women

Stress and fitness

One small trial found better VO2 max, grip strength and mood scores than placebo in sedentary female students over 30 days.

The numbers and sources
Effect
In 78 female college students in India, 1,000 mg a day for 30 days improved heart rate, VO2 max, physical work capacity and right-hand grip strength against placebo, and anxiety, depression and well-being scores improved. The 500 mg dose differed from the 1,000 mg dose on VO2 max and work capacity [6].
Population
78 sedentary female students, mean age 20.6 [6].
Sources
[6]
Caveats
One small trial. The abstract does not report effect sizes or funding.

Mixed results1

Limited

Immune function

One small trial found changes in lab immune markers in older women, without measuring infections or illness.

The numbers and sources
Effect
In 39 older women who completed 8 weeks of 2,000 mg a day of dry extract, stimulated lymphocyte proliferation rose, Th17 cells fell and Th2 cells rose, with changes in several immune gene expressions against placebo [5]. In cancer trials, T-cell percentages rose modestly [1].
Population
60 older women enrolled, 39 completed [5]. Cancer patients [1].
Sources
[5], [1]
Caveats
Lab markers, not infection or illness rates. High dropout in [5].

Not shown to help2

Limited

Alongside cancer treatment

Limited evidence: tumor response with reishi alongside chemotherapy or radiotherapy was not clearly better, and no trial recorded long-term survival.

The numbers and sources
Effect
In 5 RCTs, patients given reishi alongside chemotherapy or radiotherapy were more likely to respond than those on chemotherapy or radiotherapy alone (RR 1.50, 95% CI 0.90 to 2.51). Reishi alone did not show the same response. CD3, CD4 and CD8 percentages rose by 3.91%, 3.05% and 2.02%, and four studies reported better quality of life. No trial recorded long-term survival [1].
Population
Patients with cancer [1].
Sources
[1]
Caveats
Trial quality was generally unsatisfying and reporting inadequate. The reported interval for tumor response crosses 1 [1].
Moderate

Blood sugar, cholesterol and blood pressure

Not shown to change HbA1c, fasting glucose, cholesterol or blood pressure against placebo, with one spore oil trial finding lower lipids.

The numbers and sources
Effect
In a Cochrane review of 5 trials (398 participants), 1.4 to 3 g a day for 12 to 16 weeks did not change HbA1c (WMD -0.10%, 95% CI -1.05 to 0.85), total cholesterol, LDL or BMI against placebo. Fasting glucose, blood pressure and triglycerides did not differ. Post-meal glucose results were inconsistent [2]. A 2025 meta-analysis of 17 RCTs (971 participants) at 200 to 11,200 mg a day for 1 to 24 weeks found no effect on blood pressure, fasting glucose or the lipid profile. BMI fell by 0.43 (95% CI 0.10 to 0.77) and heart rate by 3.92 beats a minute (95% CI 0.40 to 7.45) [3]. In 110 adults with dyslipidemia, a spore oil extract for 12 weeks lowered total cholesterol, triglycerides and LDL and raised HDL compared with placebo. The abstract gives no effect sizes [4].
Population
Adults with type 2 diabetes in the analyzed trials [2]. Healthy, at-risk and chronically ill adults [3]. Adults with dyslipidemia [4].
Sources
[2], [3], [4]
Caveats
Data in [2] came from 3 small trials, and risk of bias was unclear in 4 of 5 [2]. The 2025 review rated the certainty of evidence very low for every outcome [3]. The spore oil trial tested a different product and disagrees with both reviews on lipids [4].

Claimed, not studied in people1

Untested

Sleep

Not studied in people. Used in China for insomnia for hundreds of years. In rats, an extract lengthened total and non-REM sleep in one study but not another.

No study in people. This rests on animal studies, documented traditional use.

The numbers and sources
Effect
Reishi has been used in China as a tranquilizing agent for restlessness, insomnia and palpitations for hundreds of years [10]. In freely moving rats, 3 days of an oral fruiting body extract at 80 mg/kg increased total sleep time and non-REM sleep, an effect blocked by an antibody to TNF-α [10]. In another study, a water extract at 80 and 120 mg/kg did not change sleep architecture in normal rats, but shortened sleep onset and lengthened sleep in rats given pentobarbital, an effect partly blocked by the benzodiazepine antagonist flumazenil [11].
Population
Rats and mice [10][11].
Sources
[10], [11]
Caveats
Rodent studies with short dosing, and the two disagree on sleep in normal animals. No sleep trial in people was located.

Doses studied

Diabetes trials used 1.4 to 3 g a day for 12 to 16 weeks [2]. The immune trial used 2,000 mg of dry extract a day for 8 weeks [5], and the fitness trial 500 or 1,000 mg a day for 30 days [6]. Spore powder in the tumor marker cases was taken twice a day for 1 to 2 months [7].

Risks

Reported risks2

LimitedHow often is not known

Liver injury

Case reports: two men developed liver problems on reishi products, which resolved after stopping.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
A 47-year-old man developed acute hepatitis with marked transaminase elevation after taking reishi powder with alcohol. Tests normalized within two weeks [8]. A 61-year-old man taking a commercial reishi product developed hypereosinophilia, multiple liver nodules of 1 to 3 cm and slight liver enzyme elevation. All resolved after he stopped it [9].
Population
Two case reports [8][9].
Sources
[8], [9]
Caveats
Case reports cannot give a rate. Alcohol was a co-factor in [8].
LimitedHow often is not known

Raised CA72-4 tumor marker

Case reports: five people with gut cancers had a rising CA72-4 tumor marker on reishi spore powder, which normalized after stopping.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
Five patients with gastrointestinal cancer showed rising CA72-4 after 1 to 2 months of reishi spore powder. Levels returned to normal soon after stopping, with no change in symptoms [7].
Population
Five case reports [7].
Sources
[7]
Caveats
A marker change, which can affect cancer monitoring. Patients were also receiving other treatments [7].

Checked, no increase found1

Limited

Adverse events in trials

Limited evidence: adverse events were not clearly more common than on placebo in diabetes trials, and none were serious.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
In the diabetes trials, people on reishi for four months were 1.67 times as likely to have an adverse event as those on placebo (RR 1.67, 95% CI 0.86 to 3.24), and none were serious [2]. In cancer trials, one study recorded nausea and insomnia, and no blood or liver toxicity was reported [1].
Population
Trial participants [1][2].
Sources
[2], [1]
Caveats
The interval crosses 1, and the trials were small [2].

Claims tested and not found

  1. That reishi lowers blood sugar or cholesterol in type 2 diabetes. HbA1c, fasting glucose, total cholesterol and LDL did not differ from placebo [2].
  2. That reishi lowers blood pressure. No significant difference from placebo was found [2][3].
  3. That reishi improves liver tests. Across 17 RCTs, liver enzymes did not change [3].
  4. That reishi alone shrinks tumors. Reishi without chemotherapy or radiotherapy did not show the response seen in combined treatment [1].

Sources

  1. Jin X, Ruiz Beguerie J, Sze DMY, et al. Ganoderma lucidum (Reishi mushroom) for cancer treatment. Cochrane Database of Systematic Reviews. 2016. https://doi.org/10.1002/14651858.CD007731.pub3
  2. Klupp NL, Chang D, Hawke F, et al. Ganoderma lucidum mushroom for the treatment of cardiovascular risk factors. Cochrane Database of Systematic Reviews. 2015. https://doi.org/10.1002/14651858.CD007259.pub2
  3. Jafari A, Mardani H, Mirzaei Fashtali Z, et al. The Nutritional Significance of Ganoderma lucidum on Human Health: A GRADE-Assessed Systematic Review and Meta-Analysis of Clinical Trials. Food Science & Nutrition. 2025. https://doi.org/10.1002/fsn3.70423
  4. Wang X, Wang X, Zhao L, et al. Clinical Evaluation of Ganoderma lucidum Spore Oil for Triglyceride Reduction: A Randomized, Double-Blind, Crossover Study. Nutrients. 2025. https://doi.org/10.3390/nu17050844
  5. Iser-Bem PN, Lobato TB, Alecrim-Zeza AL, et al. Ganoderma lucidum dry extract supplementation modulates T lymphocyte function in older women. British Journal of Nutrition. 2024. https://doi.org/10.1017/S0007114524001144
  6. Mitra S, Mitra M, Nandi DK, et al. Efficacy of Lingzhi or Reishi Medicinal Mushroom Ganoderma lucidum (Agaricomycetes) Supplementation on Psychological Stress and Selective Fitness Profile Parameters in Female College Students in West Bengal, India. International Journal of Medicinal Mushrooms. 2024. https://doi.org/10.1615/IntJMedMushrooms.2024055300
  7. Yan B, Meng X, Shi J, et al. Ganoderma lucidum Spore Induced CA72-4 Elevation in Gastrointestinal Cancer: A Five-Case Report. Integrative Cancer Therapies. 2014. https://doi.org/10.1177/1534735413510022
  8. Guedikian R, Kim B, Singh G, et al. Ganoderma lingzhi (Reishi Mushroom)-Induced Acute Liver Injury in the Setting of Alcohol Use: A Case Report and Review of the Literature. Cureus. 2023. https://doi.org/10.7759/cureus.45953
  9. Kogure T, Koiwai A, Fukushi D, et al. Hypereosinophilia with Hepatic Nodule Formation Caused by Ganoderma lucidum. Internal Medicine. 2021. https://doi.org/10.2169/internalmedicine.7431-21
  10. Cui XY, Cui SY, Zhang J, et al. Extract of Ganoderma lucidum prolongs sleep time in rats. Journal of Ethnopharmacology. 2012. https://doi.org/10.1016/j.jep.2011.12.020
  11. Chu QP, Wang LE, Cui XY, et al. Extract of Ganoderma lucidum potentiates pentobarbital-induced sleep via a GABAergic mechanism. Pharmacology Biochemistry and Behavior. 2007. https://doi.org/10.1016/j.pbb.2007.02.015

Everything in the library