Reishi: Mushroom of Immortality


Reishi; Ganoderma tsugae and G. lucidum

Common Names:  Hemlock Varnished Conk or Varnished Conk; Reishi (Japan); Ling Zhi (China); Hemlock Polypore, Red Reishi ….


Few species of mushrooms can match the beauty and the heart-stopping presentation of the Varnish Conks.  Whether found growing on hardwoods or on Hemlock, these closely related species show off their stunning presentation of lacquered dark red hues blending into the growing edges of yellows and whites.  Their varied growth forms jutting off the side or the top of wood are equally impressive.   Their beauty is matched only by the reputation they have garnered as a medicinal mushroom of the highest repute.

Reishi mushrooms arise from an irregularly shaped pale knob of flesh, but soon become more or less shelf-like but with a distinct stalk.   The cap is often fan to kidney shaped but is somewhat variable, tough or corky in texture, but not woody.  The upper surface of the cap is colorful with a distinctively shiny-varnished surface though in age becoming dull with dust and/or spores.  The cap color is variable from pale cream to ochre yellow along the margin and in young specimens, to deep brownish red-mahogany mature specimens.  The color varies from almost black to shades of blue-green (rare) to a wide range of warm reds.  The upper surface is wrinkled/furrowed with some concentric zonation especially in young specimens.   The margin of the cap is often enrolled.  The stalk is slender to thick and blunt, up to 11/2 inches thick and variable in length to 7 inches (or occasionally shelf-like without a discernible stalk.)  Surface and color of stalk is the same as the cap.   Pore surface white to pale yellowish and bruising brownish red.   The individual pores are minute, 4-7 per mm. and in one layer.  Spore print brown and as the mushroom matures, huge numbers of the microscopic brown spores become deposited on the top of the cap and the surface of surrounding plants coating the entire area surrounding the mushroom rusty brown.  These are annual fruits, growing for only one season with reported rare exception in southern climes.  The dead conks will persist over the winter, and can often be seen alongside new emerging fruit in early summer.

Occurrence and habitat: Reishi fruit solitary or in groups on the base or lower 12 feet of dead or living trees or, more commonly, on stumps or downed logs.  They are considered butt rotters, meaning their mycelium colonizes the major roots and the base of the trunk of the host and not the upper trunk or branches.  This distinction becomes somewhat less distinct when the mushroom is growing on logs on the forest floor.   The mushroom will occasionally fruit from roots along the surface of the ground.   The determination of species is best made by the identity of the host, softwood/conifer (G. tsugae) or hardwood/broad-leafed (G. lucidum or G. curtisii).  G. lucidum most often grows on a species of maple as a host, while G. tsugae grows almost only on hemlock.  I have found G. tsugae fruiting on spruce, but by all accounts, this is quite rare. An initial flush of fruiting bodies may start growth in the first warm weeks of late spring or early summer in New England and they will continue to grow in size throughout the summer.  Additional fruit may start growth at almost any point throughout the summer in response to wet periods, but I have not seen prolific later fruiting.  From mid-summer into autumn the mushrooms mature and release spores actively over an extended period of time.

Ecological information: Reishi is a weak parasite and an aggressive saprobe on the host tree, producing a white rot that can render the wood quite soft over a period of time. G. tsugae fruits primarily on dead trees, with the first signs of mushrooms typically seen 2-3 years after the tree dies or, on a stump, after the tree is cut.

Edibility: Reishi is not generally considered edible, though I do know several avid mycophagists (mushroom eaters) who collect and eat Reishi just as the new growth is emerging from the trunk of the tree and before any color develops on the pale knobs.  They describe it as quite good in the very young stage.  Mature mushrooms become quite bitter due to the build up of the medicinally desirable terpenes.

Look alikes: It would be difficult to confuse this complex of species with other conks due to the distinctive varnished appearance.  G. curtisii is similar and grows on hardwoods in the southern US and is considered by some to be a variant of G. lucidumG. oregonense of the Northwest US and New Mexico is much larger and thicker and grows on conifers.

Medicinal Uses:

Folk or traditional: Perhaps no other mushroom carries the degree of mystique and honor that is held by Reishi as it is known in Japan or Ling Zhi as it is known in China.  It has been an indispensable part of folk medicine in both countries for over 2,000 years, indeed, perhaps as long as 7,000 years in China.  Its other common names speak to the fame of this mushroom; “mushroom of immortality”,  “ten thousand year mushroom”, “herb of spiritual potency” (Hobbs, 1995), (Halpern & Miller, 2002).  Several of these names refer to Reishi’s reputation for promoting longevity and vigor.   Prior to the success in cultivating this mushroom over the past 20 years, it was an uncommon to rare mushroom in high demand and therefore quite expensive.   Its popularity and many traditional uses fuel its reputation as a panacea.  A short, though not comprehensive list includes, liver ailments including chronic hepatitis, nephritis, hypertension, arthritis, insomnia, bronchitis and asthma, gastrointestinal problems and cancers.   It is, above all a potent tonic and modulator of immune function.

Current uses: Scientific studies have confirmed that many of the traditional claims attributed to Reishi are indeed supported.  Various compounds extracted form G. lucidum have shown success in reducing blood pressure, blood cholesterol, and blood sugar levels.  Extracted polysaccharides and proteanated polysaccharides as well as crude mushroom extracts have shown strong immune modulating activity.  Reishi’s polysaccharide glucans and related compounds as well as some of the triterpenoids, activate immune effector cells such as macrophages, T-cells and Natural Killer cells that in turn produce a variety of cytokines such as  tumor necrosis factors and interferons.    The anti-cancer and anti-tumor action as well as anti-inflammatory action triggered by Reishi  and demonstrated in numerous experimental trials with cell cultures and animal subjects and more recently in a number of human clinical trials are based on this enhancement of host immune response.  There is evidence that Reishi triterpenes have a direct cytotoxic action on cancer cells.   See the table of medicinal effects for Reishi below.

Areas of research: Active research into the medicinal uses of Reishi is ongoing in a number of countries around the world.  Leading the efforts are China, Japan, Korea  and the US.   Because of the broad range of bioactive compounds found in Reishi, research is ongoing in a diverse number of areas with the potential for development of pharmacological products.  Briefly these include:

  • Antibiotic activity against specific various bacteria.
  • Antiviral activity HIV, influenza viruses, herpes simplex virus type 1,
  • Antitumor anticancer activity in many forms of cancer via immune stimulation
  • Anticancer action via directly cytostatic compounds
  • Immunosuppressive and anti allergic action via inhibition of histamine release
  • Anti-hypertension
  • Liver protection
  • Hypoglycemic effects in diabetic patients
  • Cholesterol lowering properties through the actions of steroids and polysaccharide fiber
  • Lipid lowering
  • Antioxidant activity through the lowering of hydroxyl free radicals.


Table 2  Pharmacological effects of whole Reishi extracts in vivo and in vitro (for references see Hobbs, 1995, or Gao et al, 2004).

•  Analgesic

• Anti-allergic activity

•  Bronchitis-preventative effect, inducing regeneration of bronchial epithelium

•  Anti-inflammatory

•  Antibacterial, against Staphylococci, Streptococci, and Bacillus pneumonia  (perhaps due to increased immune system activity)

•  Antioxidant, by eliminating hydroxyl free radicals

•  antitumor activity

•  Antiviral effect, by inducing interferon production

•  Lowers blood pressure

•  Enhances bone marrow nucleated cell proliferation

•  Cardiotonic action, lowering serum cholesterol levels with no effect on  triglycerides, enhancing myocardial metabolism of hypoxic animals, and  improving coronary artery hemodynamics

•  Central depressant and peripheral anticholinergic actions on the autonomic  nervous system reduce the effects of caffeine and relax muscles

•  Enhanced natural killer cell (NK) activity in vitro in mice

•  Expectorant and antitussive properties demonstrated in mice studies

•  General immunopotentiation

•  Anti-HIV activity in vitro and in vivo

•  Improved adrenocortical function

•  Increased production of Interleukin-1 by murine peritoneal macrophages in  vitro

•  Increased production of Interleukin-2 by murine splenocytes in vitro

Summary of Immunomodulatory effects of Ganoderma ( Gao, 2004)

  • Monocytes (cell lines): Polysaccharide extracts influenced release of cytokines including Tumor Necrosis Factor alpha, with a varying response using different polysaccharide components.
  • Macrophages (including mouse peritoneal and human cell lines): Polysaccharide components increased the proliferation and activity of macrophages and the associated release of immuno-active mediator cytokines.
  • T-Lymphocytes: In a variety of studies using human cell lines, polysaccharide extracts of Ganoderma, , both crude and refined, stimulated the action of T-Cells as evidenced by release of interferons, tumor necrosis factor-alpha, and interleukins.  The proliferation of T-Cells was also seen.
  • Natural Killer Cells: Extracts of Ganoderma were shown to stimulate NK activity in the spleens of mice in a dose-dependent manner.  In tumor-bearing mice, Ganoderma polysaccharides enhanced the cytotoxicity of NK cells in spleen cells.
  • Dendritic Cells: In a study using mouse Dendritic Cells derived from bone marrow, the exposure to polysaccharides of Ganoderma promoted maturation of the DC’s and initiation of a broader immune response as measured by the increased release of cytokines.


Key active constituents:

Polysaccharides: (over 100 different types identified )

Beta-D-glucans including Beta 1-6 and Beta 1-3 branching patterns.



Glycoproteins or proteoglycans

Terpenes (well in excess of 200 terpenes isolated)

Ling Zhi-8 protein (anti-allergenic, immuno-modulating)

Ganodermic acids – triterpenes (anti-allergenic agents, cholesterol and blood  pressure reducing)

Steroids (Ergosterols)

Collection, Preparation and use: For use as a medicinal mushroom, collect only fresh growing conks.  The ideal time for collection is when the mushroom has assumed its full growth and is actively dropping spores but before it has began to deteriorate.  This is generally in mid-late summer though is quite dependent on weather patterns.    A good indicator is when the cap margin has assumed the deep red color of maturity and not the lighter yellow of active growth.  The old, dead or dying fruits are prone to attack by molds and an examination of the pore surface will usually show this easily.  Mold would renders them unfit for use and possibly toxic.   Discard any fruiting bodies showing evidence of mold growth.

Preparations of Reishi are generally based on hot water extracts or double extraction tinctures made with a combination of ethanol and hot water extractions.  The polysaccharides and proteins are water-soluble but not all of the terpenes and steroids are effectively extracted with water.  In addition the fruiting bodies can be dried and ground into a powder and taken in capsule form or mixed into teas or juice.  In general I would suggest an initial cooking to assist in the breakdown of cell structure to release the active components.  The fruits are quite tough and resilient making grinding quite a task.

Reishi is often found as one component of a mixture of mushrooms and/or herbs in a preparation.  I make a mixed double extraction tincture of Reishi, Turkey Tail, Birch Polypore, Maitake, and Chaga for broad immunostimulating impact.  Many Traditional Chinese Medicine preparations include Reishi.

For more information, refer to my book, Mushrooms for Health; Medicinal Secrets of Northeastern Fungi.  (Link to purchase).


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