Reishi Mushroom: Benefits, Dosage, Tea and Side Effects

By Matthew Atkins · Oct 30, 2026

Reishi Mushroom

Reishi mushroom (Ganoderma lucidum) is a polypore bracket fungus that grows on hardwood trees and has been used in East Asian medicine for thousands of years. Its beta-glucans and triterpenes are studied for immune modulation, stress adaptation, sleep, fatigue, and liver support. It is typically taken as a dual extract, tea, or capsule. For an overview of other species, see our guide to medicinal mushrooms.

What Is Reishi Mushroom?

Reishi mushroom is the common English name for Ganoderma lucidum, a polypore fungus in the family Ganodermataceae (order Polyporales). The genus name Ganoderma comes from Greek roots meaning “shining skin,” while lucidum is Latin for “bright” or “shining.” It is known as lingzhi in Chinese and reishi in Japanese. Taxonomically, G. lucidum sits among the basidiomycetes, the club fungi that produce spores on specialized structures called basidia.

In the wild, G. lucidum grows as a bracket or shelf fungus, projecting horizontally from the trunks and stumps of dead or dying hardwood trees—particularly oak, maple, elm, and plum—where its white mycelium breaks down lignin and cellulose. This saprotroph and weak parasite fruits most often in warm, humid conditions near the base of standing trees or on fallen logs.

How to Identify Reishi

Reishi has a hardened, sculpted quality unlike soft-fleshed culinary mushrooms. Key identifying traits include:

• Cap: Kidney-shaped to fan-shaped, 5 to 20 centimeters across, with a smooth, rounded margin that stays lighter orange or white while actively growing.
• Surface: Coated in a glossy, varnish-like crust that looks like a thin layer of shellac, ranging from reddish-brown, mahogany, and chestnut to occasionally near-black.
• Underside and spores: Fine, pale white pores that whiten toward the edge, bruise brown when handled, and release a brown spore print.
• Stem and flesh: A lateral stipe (or sometimes stalkless attachment) with the same varnished finish as the cap, and tough, corky, fibrous flesh that must be decocted or extracted rather than eaten whole.

Foragers should watch for lookalikes. Other Ganoderma species share a family resemblance but differ in size, host tree, and spore dimensions. Several unrelated brown shelf mushrooms and decaying bracket fungi also grow on wood, though they lack reishi’s lacquered surface. Always cross-check wild specimens against local guides or with an experienced forager, and never consume a mushroom based on a single matching feature.

Beta-Glucans and Triterpenes

The medicinal properties of reishi are attributed to two main classes of bioactive compounds: polysaccharide beta-glucans and triterpenes.

Beta-glucans are long-chain carbohydrates located in the fungal cell wall. When ingested, they bind to pattern recognition receptors on immune cells, such as dectin-1 and complement receptor 3. This triggers the activation of macrophages, dendritic cells, and natural killer (NK) cells, while modulating cytokine production to support pathogen defense and maintain immune homeostasis.

Triterpenes (triterpenoids), which include ganoderic acids, are the bitter compounds responsible for reishi’s distinctive taste. Reishi is often classed as an adaptogen—a substance thought to help the body resist physical and emotional stress, partly by modulating the hypothalamic-pituitary-adrenal (HPA) axis; you can read more about what adaptogens are and how they work. In laboratory studies, triterpenes also inhibit inflammatory pathways such as NF-κB and COX-2 and help protect liver cells (hepatocytes) from damage.

Together, beta-glucans and triterpenes appear to act on immune, stress-response, and organ systems.

History as the “Mushroom of Immortality” in Asian Medicine

Reishi has been used in East Asian medicine for thousands of years as the “Mushroom of Immortality.” In Traditional Chinese Medicine (TCM), Lingzhi translates roughly to “spiritual potency.” Classical herbals placed it in the highest category of tonics—substances believed to nourish life itself rather than merely treat symptoms—alongside herbs like Korean ginseng, astragalus, and schisandra. Early Chinese physicians used it to support vitality, calm the spirit, and promote longevity. For more on this tradition, see our overview of Chinese herbs.

Because the mushroom grew rarely on decaying wood in remote forests, it became a symbol of prestige in royal texts and court records. Specimens were gathered as tribute for emperors, and dynastic art frequently depicted Lingzhi alongside figures of longevity. As its use spread to Japan and Korea, reishi retained this status as a tonic for vitality, wisdom, and good fortune.

Reishi Benefits

Modern research on Ganoderma lucidum has begun translating traditional claims into laboratory and clinical findings. Human trials have shown encouraging results for immunity, fatigue, and some metabolic markers, but much of the evidence still comes from cell and animal studies. Human studies vary widely in preparation type, dosage, and participants, which makes them hard to compare.

Immune Support

Reishi acts as an immune modulator rather than a simple stimulant. When its beta-glucans and polysaccharides bind to receptors on macrophages and dendritic cells in the gut and bloodstream, these front-line cells release signaling molecules called cytokines to coordinate a measured defense.

Research highlights two main effects on white blood cells:

• Natural killer (NK) cells: Reishi extracts can enhance NK cell activity, improving their ability to recognize infected or abnormal targets and release cytotoxic granules.
• Lymphocytes: Reishi supports the proliferation and function of T cells and B cells, which drive adaptive immunity and immunological memory.

Laboratory research suggests reishi’s compounds may work in both directions: polysaccharides encourage immune activity, while triterpenes temper excessive inflammatory signaling. This regulating character is why reishi is a common daily tonic during seasonal changes or periods of physical stress, often alongside immune herbs like astragalus.

Sleep

Reishi is traditionally used to calm the spirit and ease restless sleep. Unlike conventional sedatives, it is not associated with dependence or next-day grogginess. Research points to two possible pathways:

• GABAergic activity: Animal studies suggest reishi extracts may act on gamma-aminobutyric acid (GABA) signaling, the brain’s primary calming system.
• HPA axis regulation: By tempering the stress response, reishi may help reduce excess cortisol that can otherwise disrupt sleep.

In rodent studies, reishi extracts increased total sleep time and slow-wave (deep) sleep. Well-designed human sleep trials are still limited, so these effects have not been confirmed in people. For better-studied sleep herbs, see chamomile, kava kava, and skullcap.

Stress, Anxiety and Mood

Chronic stress can dysregulate the HPA axis, leading to abnormal cortisol patterns, mood swings, and nervous tension. Through its proposed HPA-modulating and GABAergic effects, reishi is traditionally used to calm a racing mind without heavy sedation.

The evidence is still early:

• In the neurasthenia trial described in the Fatigue section below, participants taking reishi extract reported improved well-being compared with placebo.
• Preclinical research indicates that reishi triterpenes may reduce anxiety-like behaviors in animals by regulating brain-derived neurotrophic factor (BDNF), a protein that supports neuronal health, while also reducing neuroinflammation and oxidative stress.

Human trials focused specifically on anxiety are scarce. Adaptogens with more human stress research include ashwagandha, rhodiola rosea, and holy basil—see our rhodiola vs. ashwagandha comparison.

Fatigue

Clinical studies in China have evaluated reishi in patients with neurasthenia, a condition marked by persistent physical and mental exhaustion, irritability, and low energy. In a 2005 randomized, double-blind, placebo-controlled trial of 132 patients, those taking a reishi polysaccharide extract for eight weeks reported significantly lower fatigue scores and better overall well-being than the placebo group.

Proposed mechanisms for these effects include:

• Supporting mitochondrial function and cellular adenosine triphosphate (ATP) production under stress.
• Smoothing sustained cortisol elevation via the HPA axis.
• Improving oxygen utilization and blood circulation.

Study sizes remain modest, and benefits for persistent tiredness typically emerge gradually over several weeks of consistent use. If fatigue is tied to long-term stress, you may also want to read about herbs for adrenal fatigue.

Blood Pressure and Cholesterol

Reishi may support cardiovascular health through several pathways, though human evidence is limited:

• Blood pressure: Triterpenes and peptides from reishi inhibit the angiotensin-converting enzyme (ACE) in laboratory tests, which may help blood vessels relax. Animal models show measurable drops in blood pressure, and preliminary human trials suggest similar trends, though larger studies are needed.
• Cholesterol: Beta-glucans and other polysaccharides may interfere with cholesterol absorption in the gut, while certain triterpenoids inhibit HMG-CoA reductase, a key liver enzyme for cholesterol synthesis, in lab studies. Small human studies report modest or inconsistent changes in total and LDL cholesterol.
• Circulation: Antioxidant compounds reduce lipid peroxidation in lab studies, and other constituents may reduce platelet aggregation—the same property that makes reishi a concern before surgery.

Liver Health

Because the liver processes toxins and metabolic byproducts, it constantly generates reactive oxygen species. In experimental models, reishi extracts demonstrate hepatoprotective activity by reinforcing antioxidant defenses—particularly glutathione-related pathways—and limiting lipid peroxidation within liver cells.

Preclinical research highlights two additional mechanisms:

• Anti-fibrotic potential: Reishi compounds may modulate the inflammatory signaling tied to hepatic stellate cell activation, the process that drives scar tissue (fibrosis) after chronic liver injury.
• Detoxification enzymes: Animal studies indicate reishi influences phase I and phase II liver enzyme systems, which convert and conjugate toxins for elimination.

These findings are almost entirely from animal and cell studies, and high-dose reishi powder has also been linked to rare cases of liver injury (see Liver Safety). Reishi is not a treatment for liver disease. If liver support is your main goal, milk thistle has considerably more human research behind it, and anyone with an existing liver condition should consult a healthcare professional before use.

Reishi and Cancer Research

Researchers have explored reishi as an add-on to standard cancer treatment. In laboratory and animal models, beta-glucans and ganoderic acids stimulate NK cells, macrophages, and dendritic cells, and reishi extracts slow tumor growth, inhibit angiogenesis (new blood vessel growth in tumors), and reduce the spread of certain cancer cell lines.

Human evidence is much thinner. A 2016 Cochrane review of five randomized trials found that patients who took reishi alongside chemotherapy or radiation were somewhat more likely to respond to treatment and reported some improvements in quality of life, but the trials were small and of low quality, and none showed reishi working on its own. Current evidence supports only a complementary role—never a replacement for conventional care—and patients must consult their oncology team before using reishi to avoid interactions with their treatment.

Other Claimed Benefits (Limited Evidence)

Several additional uses for reishi have been investigated primarily in cell cultures, animal models, or small, inconsistent human trials:

• Allergies: Laboratory and animal studies suggest reishi compounds may dampen histamine release and allergic inflammatory signaling, but human trials are scarce.
• Gut health: Preclinical work hints that reishi polysaccharides may support beneficial gut bacteria and intestinal barrier function, though the practical significance remains unclear.
• Blood sugar regulation: Animal experiments and a few small human studies suggest certain extracts may improve glucose metabolism, but results vary across preparations and dosages.
• Neuroprotection: Early laboratory studies indicate reishi’s antioxidant and anti-inflammatory compounds may protect nerve cells from oxidative stress, but no large-scale human trials have confirmed this.

Reishi vs. Other Medicinal Mushrooms

While reishi is used primarily as a calming, immune-modulating daily tonic, other functional mushrooms target different systems. Reishi is frequently combined with these fungi in blended formulas:

• Turkey tail: Studied primarily for gut and immune health.
• Maitake: Linked to metabolic balance and blood sugar support—see maitake mushroom benefits and uses.
• Shiitake: Used for broad nutritional and immune benefits; read more on shiitake mushroom health benefits.

Reishi vs. Chaga

While reishi focuses on stress adaptation and sleep, chaga (Inonotus obliquus) is prized for its antioxidant capacity and digestive support. Chaga contains dense concentrations of melanin and polyphenols, giving it a high antioxidant value in laboratory tests. Chaga also has a long history of traditional use for soothing the gastrointestinal tract.

Reishi vs. Cordyceps

Reishi and cordyceps (commonly Cordyceps militaris in commercial products) sit at opposite ends of the energetic spectrum. Reishi downshifts the nervous system and is typically taken in the evening to wind down. Cordyceps is used to support energy, oxygen utilization, and physical endurance, making it a popular morning or pre-workout supplement. Many users take cordyceps in the morning for stamina and reishi at night for rest.

Reishi vs. Lion’s Mane

Whereas reishi works broadly on immunity and stress resilience, lion’s mane targets the brain and nervous system. Lion’s mane contains hericenones and erinacines, compounds studied for their ability to stimulate nerve growth factor (NGF), a protein essential for maintaining and repairing neurons. Users typically choose lion’s mane for memory, focus, and cognitive clarity, or pair it with reishi to combine mental sharpness with stress reduction.

How to Use Reishi

Reishi is sold as capsules, tablets, powders, liquid tinctures (taken under the tongue or in water), and dried slices. Some users take it continuously, while others cycle their intake by taking periodic breaks after several weeks of use. Keeping a simple log of how you feel during the first few weeks can help you adjust your form and routine.

Fruiting Body vs. Mycelium Products

Commercial reishi supplements are made from either the fruiting body or the mycelium:

• Fruiting body: The visible cap and stem of the mature mushroom, where beta-glucans and triterpenes are concentrated. Whole fruiting body extracts consist almost entirely of fungal tissue.
• Mycelium: The root-like fungal network, typically cultivated on a bed of grain such as rice, oats, or millet. Unless the producer separates the mycelium from its substrate, the entire mass is dried and ground together, leaving a finished powder heavy in grain starch with low beta-glucan content.

Whole fruiting body extracts are generally the stronger choice. Avoid products that list grain among the ingredients or show high starch and low beta-glucan numbers.

Dual Extracts, Powders and Capsules

Reishi’s cell walls are made of chitin, the same tough, fibrous material found in crustacean shells. The human gut cannot easily digest raw chitin, meaning the compounds in plain ground mushroom powder remain largely locked inside.

To release both major compound classes, producers use dual extraction:

1. Hot water extraction: A decoction that softens and breaks down chitin to release water-soluble beta-glucans.
2. Alcohol extraction: Draws out the bitter, alcohol-soluble triterpenes that water cannot capture.

Water-only extracts miss most of the triterpenes, while alcohol-only tinctures leave behind the beta-glucans. When buying capsules or extract powders, look for fruiting-body dual extracts that list specific percentages of both beta-glucans and triterpenes.

How to Make Reishi Tea

Because dried reishi slices are woody and tough, they require a long simmer to break down the chitin and release their compounds:

1. Measure and rinse: Use 3 to 5 grams of dried slices (about a small handful) per serving. Rinse briefly under cool running water to remove surface dust.
2. Simmer: Place the slices in a saucepan with 4 cups of cold water per serving to account for evaporation. Bring to a boil over high heat, then reduce to a low, steady simmer. Cover partially with a lid and simmer for 45 to 60 minutes until the liquid turns deep amber or reddish-brown.
3. Strain and serve: Remove from heat, cool for a few minutes, and strain through a fine-mesh sieve.

The resulting tea is distinctly bitter and earthy; you can drink it plain or soften the flavor with honey, fresh ginger, or lemon. Leftover tea keeps in the refrigerator for up to three days, and the spent slices can be simmered a second time before composting. Reishi is often simmered together with other tonic roots—the same long-decoction method is used in how to make ginseng tea.

Reishi Coffee, Smoothies and Soups

Culinary preparations can easily mask reishi’s natural bitterness:

• Coffee and lattes: Blend a measured dose of reishi powder or concentrated decoction into black coffee, or make a latte with frothed milk, cacao powder, cinnamon, or vanilla.
• Smoothies: Mix a measured dose of reishi extract powder with sweet, rich ingredients like ripe bananas, dark berries such as blueberries or bilberries, nut butters, and raw cacao.
• Soups and broths: Stir reishi into bone stock, miso, chicken broth, or vegetable soup, where umami flavors and herbs like thyme, garlic, and root vegetables absorb its woody notes.

Reishi Dosage

Start at the lower end of the dosage range to assess tolerance before increasing:

• Raw, dried fruiting body (slices or whole powder): 3 to 15 grams daily in divided doses, simmered into a tea or decoction rather than swallowed dry.
• Concentrated extract powders or capsules (hot-water or dual extracts): Typically 1 to 3 grams daily. Clinical studies have generally used 1.5 to 5 grams daily divided into two or three servings. Check label concentration ratios (such as 10:1 or 20:1) and standardized beta-glucan percentages to gauge strength.
• Liquid tinctures (alcohol or dual-extract): 1 to 3 milliliters (roughly one to three droppers), taken one to three times daily, depending on product potency.

Best Time of Day to Take It

Most users take reishi in the evening—about 30 to 60 minutes before bed—to align its calming effects with the body’s natural wind-down period. Some split their dose between late afternoon and bedtime. However, individuals who find reishi mildly energizing rather than sedating may prefer taking it in the morning or early afternoon.

Side Effects and Safety

Reishi is generally well tolerated in moderate doses, and most users experience no adverse effects.

Common Side Effects

A minority of users experience mild, self-limiting reactions during the first days or weeks of use, which usually resolve as the body adjusts or when the dose is lowered:

• Digestive discomfort: Stomach upset, slight cramping, nausea, loose stools, or a feeling of fullness after meals.
• Dryness and irritation: Dry mouth, persistent thirst, dry skin, or mild throat scratchiness (usually relieved by staying hydrated).
• Dizziness: Occasional lightheadedness.
• Skin reactions: Faint redness, itching, or small localized rashes on the arms, chest, or face. Stop taking reishi and seek medical advice if you develop a spreading rash, hives, or swelling.

Liver Safety

While reishi extracts are studied for liver protection, a small number of case reports have described liver injury—including elevated liver enzymes and, rarely, severe hepatitis—in people taking reishi powder, often at high doses over extended periods. Many of these cases involved confounding factors such as other medications, pre-existing liver conditions, or unverified supplements.

Because fungi readily absorb substances from their growing environment, poorly manufactured powders may contain heavy metals, pesticides, microbial contaminants, residual extraction solvents, fillers, or misidentified species. To minimize risk, avoid self-prescribed megadoses, choose third-party tested extracts over unverified raw powders, and consider routine blood work if taking concentrated supplements for months at a time. Stop taking reishi and see a doctor if you notice yellowing skin or eyes, dark urine, or upper-right abdominal pain. Anyone taking medications processed by the liver should consult a clinician before starting reishi.

Bleeding Disorders and Surgery

Reishi has mild antiplatelet properties that may slow blood clotting. For individuals with bleeding disorders—such as hemophilia, von Willebrand disease, or low platelet counts—reishi can increase the risk of prolonged bleeding from minor cuts, nosebleeds, and bruising. Seek prompt medical attention if you notice unusual nosebleeds or easy bruising while taking it.

Because of this effect, stop taking reishi at least two weeks before any scheduled surgery, including dental extractions and minor procedures. Always inform your surgeon and anesthesiologist about reishi use.

Drug Interactions

Consult a healthcare provider before combining reishi with the following medications:

• Anticoagulants and antiplatelets (e.g., warfarin, heparin, clopidogrel, daily aspirin): Reishi may add to blood-thinning effects, raising the risk of bruising and bleeding. The same caution applies to other herbs that affect clotting, such as ginkgo biloba.
• Immunosuppressants (e.g., cyclosporine, tacrolimus): Because reishi stimulates immune cell activity, it may counteract medications prescribed to prevent organ transplant rejection or manage autoimmune diseases.
• Antihypertensives: Combining reishi with blood pressure medications may cause additive low blood pressure, leading to dizziness or fainting.
• Diabetes medications (e.g., insulin, oral hypoglycemics): Because reishi may lower blood glucose, concurrent use could increase the risk of hypoglycemia; monitor blood sugar closely.
• Narrow-therapeutic-window drugs: Any medication requiring precise blood levels should be reviewed by a pharmacist or physician before adding reishi.

Pregnancy and Breastfeeding

No controlled clinical trials have evaluated reishi in pregnant or breastfeeding women, so its effects on fetal development and breast milk are unknown. Health authorities and herbal practitioners recommend avoiding reishi during pregnancy and lactation.

Who Should Avoid Reishi

In addition to pregnant or nursing women, people with bleeding disorders, and those within two weeks of surgery, the following groups should avoid reishi or use it only under medical supervision:

• People with low blood pressure (hypotension): Reishi’s blood pressure-lowering effects can cause lightheadedness or fainting.
• People with autoimmune conditions: In conditions such as rheumatoid arthritis, lupus, or multiple sclerosis, reishi’s immune-stimulating effects could theoretically aggravate an overactive immune response.
• People with liver disease: Given the rare case reports of liver injury, use reishi only under medical supervision.

How to Buy Quality Reishi

Because mushrooms accumulate compounds from their environment, evaluate suppliers using four criteria:

• Third-party testing: Look for brands that publish batch-specific Certificates of Analysis (COAs) from independent laboratories verifying both species identity and potency (measured beta-glucan and triterpene levels).
• Heavy metal screening: Fungi efficiently absorb lead, cadmium, arsenic, and mercury from soil and wood. Ensure the COA tests every batch against recognized safety thresholds for these metals as well as microbial contaminants.
• Sourcing transparency: Labels should specify the fungal part used (fruiting body, mycelium, or spore powder), the cultivation method (natural hardwood logs vs. indoor facilities), and the drying and extraction processes.
• Organic certification: A recognized organic seal confirms the mushroom was grown without synthetic pesticides or fertilizers.

How to Grow Reishi at Home

Home cultivation starts with purchasing reishi spawn or expanding a liquid culture. Depending on your space and equipment, you can use three main substrates:

• Supplemented sawdust blocks: Mix hardwood sawdust (such as oak or maple) with a small amount of nutritional bran, moisten to field capacity, and pack into heat-resistant filter-patch bags. Sterilize the bags in a pressure cooker, cool, and inoculate with grain spawn inside a still-air box or in front of a laminar flow hood. Incubate in a warm, dark space for several weeks until fully colonized and white, then cut slits in the bag and move it to a humid fruiting chamber with fresh air exchange.
• Grain jars: Inoculate sterilized jars of grain and shake to speed colonization. You can use this grain spawn to inoculate sawdust blocks, or fruit smaller yields directly from the jars by removing the lids inside a humid chamber.
• Outdoor hardwood logs: In late winter or early spring, drill holes along freshly cut oak or other hardwood logs, insert spawn plugs, and seal with wax. Stack the logs in a shaded, moist area and water during dry spells. Logs typically take a full season or more to colonize before fruiting and can produce for several years.

Reishi Mushroom FAQ

Is reishi the same as lingzhi? Yes. Lingzhi is the Chinese name and reishi is the Japanese name for the same mushroom, Ganoderma lucidum. Some products sold as lingzhi or reishi are closely related Ganoderma species, so check the label for the Latin name.

Can you take reishi every day? Reishi is traditionally taken daily over weeks or months, and no habituation is known. Some traditional protocols recommend periodic breaks after several weeks to reassess how your body responds. Long-term high-dose use should be discussed with a doctor because of rare liver case reports.

Why is reishi so bitter, and how can I avoid the taste? The bitterness comes from its triterpenes (such as ganoderic acids). If you dislike the flavor of teas or powders mixed into coffee, smoothies, or broth, opt for capsules or tablets.

How quickly does reishi work? Reishi is a slow-acting tonic rather than a rapid stimulant or sedative. While some people notice subtle relaxation in the evening within days, benefits for fatigue, stress resilience, and immunity typically take several weeks of consistent daily use.

What is the shelf life of reishi supplements? Whole dried slices and sealed extracts keep for extended periods when stored in a cool, dark, dry place. Once opened, powders and tinctures should be kept away from heat, light, and moisture and used within the timeframe printed on the label.

Can I take reishi with other adaptogens? Yes, reishi is often combined with other mushrooms and adaptogens such as cordyceps, lion’s mane, or ashwagandha. Start one new supplement at a time so you can tell which one is causing any effects. See our full list of herbs by health condition for other options.

Matthew Atkins

Matthew studied biology and has worked in conservation. He's been interested in medicinal herbs for many years. More about HerbsList

This page is for general information only and isn't medical advice. Talk with a doctor or pharmacist before taking any herb or supplement. Full disclaimer