Reishi

Reishi is Ling Zhi, the “mushroom of immortality”, and its classical reputation is longevity rather than any single complaint. The dried fruiting body is sweet and neutral, and it enters the heart, liver and lung channels ^{31Reference 31Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg}.

It tonifies the heart, calms and anchors the Shen, stops cough and wheezing, dislodges phlegm, and tonifies the spleen, the Qi and the blood ^{31Reference 31Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg}. It is best known for the heart and the Shen: reishi is given to protect the Qi of the heart and to relieve what the texts describe as a knotted, tight chest ^{31Reference 31Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg}.

It was taken over long periods rather than in short courses. The spores are held to be especially rich in jing and are described as an elixir of life ^{30Reference 30Rogers · 2011The fungal pharmacy: The complete guide to medicinal mushrooms and lichens of North America [Adobe Digital Editions version]}.

The usual dose is 3–15 g, decocted for twenty minutes, and it is considered suitable in pregnancy ^{31Reference 31Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg}.

For altitude sickness it is often combined with chrysanthemum, rhodiola and safflower seed ^{30Reference 30Rogers · 2011The fungal pharmacy: The complete guide to medicinal mushrooms and lichens of North America [Adobe Digital Editions version]}. Other recorded uses include Hashimoto’s disease, foot baths for gout, and immune regulation ^{30Reference 30Rogers · 2011The fungal pharmacy: The complete guide to medicinal mushrooms and lichens of North America [Adobe Digital Editions version]}. The red and purple forms are considered the most valuable ^{30Reference 30Rogers · 2011The fungal pharmacy: The complete guide to medicinal mushrooms and lichens of North America [Adobe Digital Editions version]}.

Reishi has been used medicinally in Asia for more than 2,000 years ^{2Reference 2Klupp NL et al. · 2015Meta-analysisGanoderma lucidum mushroom for the treatment of cardiovascular risk factors — systematic review, meta-analysisView study →}. It is the most widely depicted mushroom in the art of Japan, Korea and China, and appears on temples, tapestries, statues and paintings ^{30Reference 30Rogers · 2011The fungal pharmacy: The complete guide to medicinal mushrooms and lichens of North America [Adobe Digital Editions version]}.

Its rarity made it valuable, and wild reishi was mostly available to emperors and royalty. It was recorded in many early medical texts as a herb for long life ^{30Reference 30Rogers · 2011The fungal pharmacy: The complete guide to medicinal mushrooms and lichens of North America [Adobe Digital Editions version]}.

It was used for liver ailments, lung conditions, kidney disease, nerve pain, high blood pressure, gastric ulcers and insomnia. The branched “antler” form was the most prized, and was taken to support sexual function in men and women ^{30Reference 30Rogers · 2011The fungal pharmacy: The complete guide to medicinal mushrooms and lichens of North America [Adobe Digital Editions version]}.

Dried specimens were hung over doors to ward off evil, and placed on the graves of shamans to protect against evil spirits ^{30Reference 30Rogers · 2011The fungal pharmacy: The complete guide to medicinal mushrooms and lichens of North America [Adobe Digital Editions version]}.

Reishi has been taken as tinctures, teas, decoctions and powders, brewed into beer and wine, and eaten raw ^{30Reference 30Rogers · 2011The fungal pharmacy: The complete guide to medicinal mushrooms and lichens of North America [Adobe Digital Editions version]}.

Western herbalists took up reishi in the late 20th century, following its East Asian reputation and the research on its triterpenes and beta-glucans ^{30Reference 30Rogers · 2011The fungal pharmacy: The complete guide to medicinal mushrooms and lichens of North America [Adobe Digital Editions version]}.

It is used as an adaptogen and immune tonic for stress, fatigue, convalescence and immune support. It is taken as a 1:2 liquid extract, about 30–60 mL a week, or as a dual water-and-alcohol extract that captures both the water-soluble polysaccharides and the alcohol-soluble triterpenes ^{30Reference 30Rogers · 2011The fungal pharmacy: The complete guide to medicinal mushrooms and lichens of North America [Adobe Digital Editions version]}.

In 34 patients with advanced cancer, 12 weeks of Ganopoly (a water-soluble polysaccharide fraction, 1800 mg three times daily) raised NK-cell activity, IL-2, IL-6 and interferon-γ, and lowered IL-1 and TNF-α ^{3Reference 3Gao Y et al. · 2003Clinical trialEffects of Ganopoly (a Ganoderma lucidum polysaccharide extract) on the immune functions in advanced-stage cancer patients — clinical trialView study →}. A follow-up open-label study in 36 patients with advanced lung cancer, at the same 5.4 g daily dose, found no significant change in NK activity, T-cell subsets or cytokines on average, though some individual patients responded strongly ^{4Reference 4Gao Y et al. · 2005Clinical trialEffects of water-soluble Ganoderma lucidum polysaccharides on the immune functions of patients with advanced lung cancer — clinical trialView study →}.

In a 2024 double-blind trial in 39 older women, 2000 mg a day of a dry extract for 8 weeks increased lymphocyte proliferation. It also shifted CD4⁺ gene expression and T-cell subsets toward a regulatory, anti-inflammatory profile, with more FoxP3, TGF-β and IL-10 expression and fewer Th17 cells ^{39Reference 39Iser-Bem PN et al. · 2024RCTGanoderma lucidum dry extract supplementation modulates T lymphocyte function in older women — randomised controlled trialView study →}.

The effect is attributed to the beta-glucans, which engage pattern-recognition receptors on innate immune cells. A review of fungal beta-glucan RCTs supports immune-parameter changes across heterogeneous designs ^{14Reference 14Vlassopoulou M et al. · 2021Systematic reviewEffects of fungal beta-glucans on health — a systematic review of randomised controlled trialsView study →}.

Gap: the human trials are small and mostly open-label. Their clinical meaning, such as fewer infections or better outcomes, has not been tested.

The 2016 Cochrane review pooled five randomized trials (373 patients) of G. lucidum given alongside chemotherapy or radiotherapy. Patients receiving reishi were more likely to respond to treatment, showed enhanced immune function and reported better quality of life — but the authors rated the methodological quality poor and concluded reishi should not be used as a first-line or sole treatment ^{1Reference 1Jin X et al. · 2016Meta-analysisGanoderma lucidum (Reishi mushroom) for cancer treatment — systematic review, meta-analysisView study →}.

A 2023 systematic review of medicinal-mushroom supplements in cancer reached the same cautious position ^{29Reference 29Narayanan et al. · 2023Systematic reviewMedicinal mushroom supplements in cancer: a systematic review of clinical studies — systematic reviewView study →}.

Preclinically, ganoderic acid A enhances oxaliplatin’s tumor suppression in a colon-cancer mouse model ^{22Reference 22Song Z et al. · 2023AnimalGanoderic acid A enhances tumour-suppression function of oxaliplatin via inducing the cytotoxicity of T cells — mouse modelView study →}, and triterpene fractions trigger apoptosis in multiple cancer cell lines ^{15Reference 15Yuen JW · 2005ReviewAnticancer effects of Ganoderma lucidum: a review of scientific evidence — reviewView study →}.

Gap: every positive human result is as an adjunct to standard therapy, in small low-quality trials — there is no evidence reishi treats cancer on its own, and the benefits need confirmation in adequately powered blinded trials.

The human data are mixed. A four-week double-blind crossover study in 18 healthy adults (1.44 g a day) found no significant change in any antioxidant, heart-risk or DNA-damage marker, though antioxidant capacity in the urine rose ^{6Reference 6Wachtel-Galor S et al. · 2004Clinical trialGanoderma lucidum (“Lingzhi”), a Chinese medicinal mushroom: biomarker responses in a controlled human supplementation study — controlled clinical trialView study →}. An earlier study by the same group had found a short-lived rise in plasma antioxidant power after ingestion ^{6Reference 6Wachtel-Galor S et al. · 2004Clinical trialGanoderma lucidum (“Lingzhi”), a Chinese medicinal mushroom: biomarker responses in a controlled human supplementation study — controlled clinical trialView study →}.

A later double-blind crossover trial in 42 healthy volunteers, using a triterpenoid- and polysaccharide-enriched extract (225 mg a day for six months), reported higher total antioxidant capacity and glutathione, and lower markers of lipid and DNA oxidation ^{5Reference 5Chiu HF et al. · 2017RCTTriterpenoids and polysaccharide peptides-enriched Ganoderma lucidum: a randomised, double-blind, placebo-controlled crossover study of antioxidation and hepatoprotective efficacy in healthy volunteers — randomised controlled trialView study →}. The 2025 meta-analysis found a significant rise in glutathione peroxidase across trials ^{37Reference 37Jafari A et al. · 2025Meta-analysisThe Nutritional Significance of Ganoderma lucidum on Human Health: A GRADE-Assessed Systematic Review and Meta-Analysis of Clinical Trials — systematic review, meta-analysisView study →}.

Preclinically the effect is consistent: extracts raise glutathione and inhibit lipid peroxidation across many models.

Gap: the pooled human evidence is rated very low in certainty ^{37Reference 37Jafari A et al. · 2025Meta-analysisThe Nutritional Significance of Ganoderma lucidum on Human Health: A GRADE-Assessed Systematic Review and Meta-Analysis of Clinical Trials — systematic review, meta-analysisView study →}, and the trials measure blood markers rather than clinical outcomes.

In rats, ethanolic extract dose-dependently blunted CCl₄-induced ALT/AST rises and restored antioxidant enzymes, comparably to silymarin ^{16Reference 16Johra FT et al. · 2023AnimalAmelioration of CCl₄-induced oxidative stress and hepatotoxicity by Ganoderma lucidum in Long Evans rats — animal modelView study →}. Isolated ganoderic acid likewise protected mice against CCl₄ injury ^{17Reference 17Li YQ · 2006In vitroAnti-hepatitis B activities of ganoderic acid from Ganoderma lucidum — in vitro and mouse studyView study →}.

In the six-month trial in 42 healthy volunteers, the enriched extract lowered the liver enzymes GOT and GPT by 42% and 27%, and ultrasound showed a change from mild fatty liver to normal ^{5Reference 5Chiu HF et al. · 2017RCTTriterpenoids and polysaccharide peptides-enriched Ganoderma lucidum: a randomised, double-blind, placebo-controlled crossover study of antioxidation and hepatoprotective efficacy in healthy volunteers — randomised controlled trialView study →}. A 2023 review catalogues protection across NAFLD, alcohol- and toxin-induced models ^{28Reference 28Ahmad MF et al. · 2023ReviewGanoderma lucidum: novel insight into hepatoprotective potential with mechanisms of action — reviewView study →}. The mechanism centres on antioxidant defence and suppression of hepatic inflammatory signalling.

Gap: the strong data come from animal toxin-challenge models. The human evidence is a single trial in healthy people, not in liver-disease patients, and reishi powder has itself been linked to rare cases of severe liver injury ^{27Reference 27Wanmuang H et al. · 2007Case reportFatal fulminant hepatitis associated with Ganoderma lucidum (Lingzhi) mushroom powder — case reportView study →}.

Several small trials point the same way. A multicenter RCT in 132 neurasthenia patients found Ganopoly (1800 mg three times daily, 8 weeks) reduced fatigue and improved wellbeing versus placebo ^{9Reference 9Tang W et al. · 2005RCTA randomised, double-blind and placebo-controlled study of a Ganoderma lucidum polysaccharide extract in neurasthenia — randomised controlled trialView study →}.

A pilot RCT in 48 breast-cancer patients on endocrine therapy reported that reishi spore powder improved cancer-related fatigue and quality of life over 4 weeks ^{10Reference 10Zhao H et al. · 2012Clinical trialSpore powder of Ganoderma lucidum improves cancer-related fatigue in breast cancer patients undergoing endocrine therapy: a pilot clinical trialView study →}. In 64 women with fibromyalgia, 6 g a day of reishi for 6 weeks improved aerobic endurance, flexibility and speed, while the comparison group taking carob flour did not improve ^{13Reference 13Collado-Mateo D et al. · 2015RCTGanoderma lucidum improves physical fitness in women with fibromyalgia — randomised controlled trialView study →}.

In a 2024 trial in 78 sedentary female students, 1000 mg a day for 30 days improved heart rate, VO₂max and work capacity, and lowered anxiety and depression scores, compared with placebo. A 500 mg dose was less effective ^{40Reference 40Mitra S et al. · 2024RCTEfficacy 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 — randomised controlled trialView study →}.

Gap: all four trials are small and short, two are pilot-scale, and the outcomes are questionnaires or fitness tests. The effect sizes and how long they last have not been established.

Two 2008 double-blind RCTs from the same Japanese group tested a reishi ethanol extract selected for strong 5α-reductase inhibition in men with lower urinary tract symptoms. A dose-ranging study identified 6 mg/day as effective ^{12Reference 12Noguchi M et al. · 2008RCTEffect of an extract of Ganoderma lucidum in men with lower urinary tract symptoms: a double-blind, placebo-controlled, randomised dose-ranging study — randomised controlled trialView study →}, and a confirmatory trial found that dose improved the International Prostate Symptom Score (~2.1 points) versus placebo, without affecting prostate volume, PSA or urine flow ^{11Reference 11Noguchi M et al. · 2008RCTRandomised clinical trial of an ethanol extract of Ganoderma lucidum in men with lower urinary tract symptoms — randomised controlled trialView study →}.

Gap: this is a modest symptomatic benefit from one research program using a specific 6 mg extract, not replicated independently.

The anti-inflammatory label rests almost entirely on isolated triterpenes in cell and animal models. The lanostane triterpene ganoderterpene A suppressed nitric-oxide production in LPS-activated microglia via MAPK and TLR-4/NF-κB inhibition (IC₅₀ ~7 μM) ^{20Reference 20Kou RW et al. · 2021In vitroGanoderterpene A, a new triterpenoid from Ganoderma lucidum, attenuates LPS-induced inflammation via suppressing MAPK and TLR-4/NF-κB pathways in BV-2 cells — in vitroView study →}, and lucidone D reduced inflammatory mediators in LPS-stimulated macrophages ^{21Reference 21Feng X · 2019In vitroAnti-inflammatory, anti-nociceptive and sedative-hypnotic activities of lucidone D extracted from Ganoderma lucidum — in vitro and mouse studyView study →}.

A 2026 systematic review of 23 preclinical studies found that reishi triterpenes consistently lowered TNF-α, IL-1β and IL-6, mainly by downregulating MAPK and TLR-4/NF-κB signalling. Its meta-analysis of the cell data confirmed lower nitric oxide, IL-6 and TNF-α ^{41Reference 41Pozzobon RG et al. · 2026Meta-analysisAnti-Inflammatory Potential of Ganoderma lucidum Triterpenes: A Systematic Review and Meta-Analysis of Preclinical Evidence — systematic review of preclinical studiesView study →}.

Gap: these are single-compound and extract results in cells and animals. No whole-herb human anti-inflammatory trial has been run.

Antiviral activity is preclinical and preparation-specific. Ganoderic acid inhibited hepatitis B virus replication in HepG2215 cells ^{17Reference 17Li YQ · 2006In vitroAnti-hepatitis B activities of ganoderic acid from Ganoderma lucidum — in vitro and mouse studyView study →}, and a mycelial proteoglycan blocked herpes simplex (HSV-1/HSV-2) entry in vitro ^{18Reference 18Li Z et al. · 2005In vitroPossible mechanism underlying the antiherpetic activity of a proteoglycan isolated from the mycelia of Ganoderma lucidum — in vitroView study →}.

The only human report — faster resolution of recurrent genital and labial herpes — used a six-herb mixture (WTTCGE) containing reishi, so the effect cannot be attributed to reishi alone ^{19Reference 19Hijikata Y et al. · 2007Clinical trialHerbal mixtures containing the mushroom Ganoderma lucidum improve recovery time in patients with herpes genitalis and labialis — clinical trial (herbal mixture)View study →}.

Gap: no human trial has tested reishi by itself against any virus; the mechanistic work uses specific fractions that differ from common consumer preparations.

Preclinical work is encouraging — polysaccharides (ganoderan B and C) lower blood glucose in animal models — but the human test failed. In an 84-participant double-blind RCT, 3 g/day of reishi (± Cordyceps) for 16 weeks had no effect on HbA1c or fasting glucose in type 2 diabetes with metabolic syndrome ^{7Reference 7Klupp NL et al. · 2016RCTA double-blind, randomised, placebo-controlled trial of Ganoderma lucidum for the treatment of cardiovascular risk factors of metabolic syndrome — randomised controlled trialView study →}. The 2025 meta-analysis also found no effect on fasting glucose across trials ^{37Reference 37Jafari A et al. · 2025Meta-analysisThe Nutritional Significance of Ganoderma lucidum on Human Health: A GRADE-Assessed Systematic Review and Meta-Analysis of Clinical Trials — systematic review, meta-analysisView study →}.

Gap: the best human trials were null and the positive glycemic data are all animal, so the traditional anti-diabetic claim is not supported in people at the doses tested.

The 2015 Cochrane review included five trials with 398 participants and found no significant effect on blood pressure, lipids or HbA1c ^{2Reference 2Klupp NL et al. · 2015Meta-analysisGanoderma lucidum mushroom for the treatment of cardiovascular risk factors — systematic review, meta-analysisView study →}.

A 12-week crossover trial in 26 people with borderline high blood pressure or cholesterol (1.44 g a day) found reishi well tolerated but with no change in blood pressure or body weight. Plasma insulin and insulin resistance were lower on reishi than on placebo ^{8Reference 8Chu TT et al. · 2012RCTStudy of potential cardioprotective effects of Ganoderma lucidum (Lingzhi): results of a controlled human intervention trial — randomised controlled trialView study →}. The 16-week metabolic-syndrome RCT was null on every cardiovascular outcome ^{7Reference 7Klupp NL et al. · 2016RCTA double-blind, randomised, placebo-controlled trial of Ganoderma lucidum for the treatment of cardiovascular risk factors of metabolic syndrome — randomised controlled trialView study →}, and the 2025 meta-analysis found no effect on blood pressure or the lipid profile ^{37Reference 37Jafari A et al. · 2025Meta-analysisThe Nutritional Significance of Ganoderma lucidum on Human Health: A GRADE-Assessed Systematic Review and Meta-Analysis of Clinical Trials — systematic review, meta-analysisView study →}.

Against this, a 2025 double-blind trial in 110 people with dyslipidaemia found that reishi spore oil lowered total cholesterol, triglycerides and LDL and raised HDL over 12 weeks, compared with placebo ^{38Reference 38Wang X et al. · 2025RCTClinical Evaluation of Ganoderma lucidum Spore Oil for Triglyceride Reduction: A Randomized, Double-Blind, Crossover Study — randomised controlled trialView study →}. A meta-analysis of 49 animal studies also found lower blood lipids ^{42Reference 42Aref M et al. · 2023Meta-analysisEffect of Ganoderma lucidum on serum lipid profiles: A systematic review and meta-analysis on animal studies — systematic review of animal studiesView study →}.

Gap: the placebo-controlled trials of the fruiting body and polysaccharide extracts are null or inconclusive. The one positive human lipid result is from spore oil, a separate lipid fraction, and does not carry over to other preparations.

Ganoderic acid A protected HT22 neurons against amyloid-β(25–35) toxicity via ERK/MAPK ^{24Reference 24Shao N et al. · 2024In vitroGanoderic acid A alleviates Aβ25-35-induced HT22 cell apoptosis through the ERK/MAPK pathway — in vitroView study →} and, in a separate cell model, reduced ferroptosis via NRF2/SLC7A11/GPX4 signaling ^{23Reference 23Lu Q et al. · 2025In vitroThe anti-Alzheimer’s disease effects of ganoderic acid A by inhibiting ferroptosis-lipid peroxidation via NRF2/SLC7A11/GPX4 signalling — in vitroView study →}.

Gap: both are in vitro reports framed around Alzheimer’s disease, on a single compound. There are no animal-behaviour or human cognitive data.

Reishi is a classical shen tonic for restlessness and insomnia in Chinese medicine ^{31Reference 31Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg}, and animal work supports a sedative-hypnotic action. Lucidone D showed sedative-hypnotic activity in mice ^{21Reference 21Feng X · 2019In vitroAnti-inflammatory, anti-nociceptive and sedative-hypnotic activities of lucidone D extracted from Ganoderma lucidum — in vitro and mouse studyView study →}.

A 2024 study of five medicinal Polyporales mushrooms used in China for insomnia, reishi among them, found that all five lengthened sleep in a mouse pentobarbital model. Six shared triterpenes, four ganoderic acids (B, C1, F and H) and two ganoderenic acids, were the main sedative-hypnotic compounds ^{47Reference 47Chen W et al. · 2024AnimalIdentification of sedative-hypnotic compounds shared by five medicinal Polyporales mushrooms using UPLC-Q-TOF-MS/MS-based untargeted metabolomics — mouseView study →}.

In rats with a model of sporadic Alzheimer’s disease, a spore extract with the spore wall removed restored total, REM and non-REM sleep time over 14 days ^{49Reference 49Qin Y et al. · 2024AnimalGanoderma lucidum spore extract improves sleep disturbances in a rat model of sporadic Alzheimer’s disease — ratView study →}.

Gap: the evidence is confined to isolated constituents and animal sleep models; no controlled human sleep trial of reishi has been run.

Side effects. The most common complaints in trials are mild, transient digestive upset, dizziness and dry mouth. Reishi was well tolerated in a 12-week controlled trial ^{8Reference 8Chu TT et al. · 2012RCTStudy of potential cardioprotective effects of Ganoderma lucidum (Lingzhi): results of a controlled human intervention trial — randomised controlled trialView study →}.

Liver. Two patients, one in Hong Kong in 2004 and one in Thailand in 2005, developed liver injury after switching from traditionally boiled lingzhi to lingzhi powder for one to two months. The second case was fatal fulminant hepatitis. Both were also taking other medicines ^{27Reference 27Wanmuang H et al. · 2007Case reportFatal fulminant hepatitis associated with Ganoderma lucidum (Lingzhi) mushroom powder — case reportView study →}.

Anticoagulant and antiplatelet drugs. A water extract of reishi slowed platelet aggregation in blood from 15 healthy volunteers, and 33 patients with atherosclerotic disease who took 1 g three times a day for two weeks showed reduced platelet aggregation ^{25Reference 25Tao J · 1990In vitroExperimental and clinical studies on the inhibitory effect of Ganoderma lucidum on platelet aggregation — human and in vitro studyView study →}. A protease from the mushroom also breaks down fibrin ^{26Reference 26Kumaran S et al. · 2011In vitroScreening, isolation and purification of a fibrinolytic protease from Ganoderma lucidum and evaluation of its antithrombotic activity — in vitro and in vivoView study →}. Reishi may add to the effect of anticoagulant and antiplatelet drugs, and is best stopped before surgery.

Blood-pressure drugs. Combining reishi with ACE inhibitors and other blood-pressure medicines is a traditional caution, based on its ACE-inhibiting constituents. Controlled trials found no effect on blood pressure, so any added effect is theoretical ^{2,8Reference 2Klupp NL et al. · 2015Meta-analysisGanoderma lucidum mushroom for the treatment of cardiovascular risk factors — systematic review, meta-analysisView study →Reference 8Chu TT et al. · 2012RCTStudy of potential cardioprotective effects of Ganoderma lucidum (Lingzhi): results of a controlled human intervention trial — randomised controlled trialView study →}.

Immunosuppressants. Reishi’s beta-glucans act on the immune system ^{14Reference 14Vlassopoulou M et al. · 2021Systematic reviewEffects of fungal beta-glucans on health — a systematic review of randomised controlled trialsView study →}, so it could in principle work against immunosuppressant drugs. This has not been studied.

Drug metabolism. Reishi’s effect on drug-metabolising enzymes has not been tested in people. In rat liver microsomes, a reishi polysaccharide inhibited CYP2E1, CYP1A2 and CYP3A in a dose-dependent way ^{43Reference 43Wang X et al. · 2007In vitroEffects of Ganoderma lucidum polysaccharide on CYP2E1, CYP1A2 and CYP3A activities in BCG-immune hepatic injury in rats — rat, in vitro microsomesView study →}. In drug-resistant leukaemia cells it lowered the expression of MDR-1, the gene for the drug pump P-glycoprotein ^{44Reference 44Li WD et al. · 2008In vitroReversal effect of Ganoderma lucidum polysaccharide on multidrug resistance in K562/ADM cell line — in vitroView study →}. Whether either finding changes the levels of any medicine in people is unknown.

Children. Reishi has not been studied in children.

Quality. Several varnished Ganoderma look-alikes have long been sold as reishi, and the lingzhi cultivated in China is now treated as a separate species from the European G. lucidum ^{33,36Reference 33Loyd et al. · 2018Elucidating “lucidum”: distinguishing the diverse laccate Ganoderma species of the United States — taxonomy (phylogenetics)View study →Reference 36Du et al. · 2023Re-examination of the holotype of Ganoderma sichuanense (Ganodermataceae, Polyporales) and a clarification of the identity of Chinese cultivated Lingzhi — taxonomy (phylogenetics)View study →}. Mycelium grown on grain is often sold with much of its grain substrate still in it.