March 2026

Polysaccharides in herbal medicine

• Week 1: Polysaccharides in herbal medicine
• Week 2: Marshmallow – All The Juicy Details
• Week 3: Astragalus – An Ancient Remedy For a Modern Condition
• Week 4: Reishi – The Mushroom Of Immortality

Reishi is a very popular remedy. You can find reishi in Whole Foods, Co-ops, natural health stores, and online. However, the quality of these products varies, and the medicinal claims associated with them are not always scientifically supported. Reishi is not a cure-all remedy and should be used with caution in specific conditions, along with specific herbs and medications. 

Ganoderma mushroom naturally grows in deciduous forests on fallen, decaying trees, specifically hemlock trees.

Reishi – The Mushroom of Immortality

Plant ID

Name: Reishi (Japanese name)

Botanical name: Ganoderma lucididum

Common names: Ling Zhi (Chinese name), Happy herb,  Ten-thousand-year mushroom, Miraculous chi, Auspicious herb, Good omen plant,  Mushroom of Immortality, and Herb of Spiritual Potency.

What’s in the name

 The Latin word lucidus means “shiny” or “brilliant” and refers to the glossy appearance of the surface of the mushroom.

Botanical Family: Ganodermataceae 

Part used: fruiting body

Degree: 3rd degree

Description

 Reishi mushrooms grow in a shelf-like form on decaying wood, often at the base of deciduous trees in temperate and tropical regions. The cap is commonly 2 to 8 inches (5–20 cm) across, with some reaching up to 14 inches (35 cm), and 1 to 2 inches (2.5–5 cm) thick. It almost always has a stem (called a stipe) that is light brown to reddish brown, glossy, about 1.5 times as wide as the cap.

The inside flesh of the mushroom is pinkish-beige to cinnamon, firm to the touch, and cork-like. When cut open, there are ring-like growth layers. 

Growing

Reishi grows on decaying hardwood tree stumps in tropical and subtropical rainforests in Asia, Africa, and the United States. There are attempts to cultivate reishi mushrooms, but, as far as I can tell, the resulting mushrooms do not have the same pharmacological profile as wild-grown reishi.

That doesn’t necessarily mean that all cultivated reishi are not potent; instead, it suggests asking who, where, and how the mushroom was harvested, the extraction method, and whether it was tested to ensure it contains the constituents it claims to contain. 

History and lore

Ancient Chinese herbalists called reishi Lingzhi (灵芝) “herb of spiritual potency.” The Shennong (meaning the holy farmer) is attributed to Emperor Yan, the first, who laid the foundation of China’s agriculture. Of reishi, he wrote, “If eaten customarily, it makes your body light and young, lengthens your life, and turns you into one like the immortal who never dies.”

Traditional Chinese Medicine physicians adopted the phrase “the mushroom of immortality” to describe all the health benefits that were attributed to reishi.  However, reishi was relatively rare in nature, so for a long time, it was reserved exclusively for nobility.

A revered plant has often been depicted alongside other powerful symbols in art, including silk paintings, wall paintings, folk tales, myths, and poems.  

Energetic architecture

Taste: Bitter, earthy

Energetics

Temperature: Slightly warming

Fluid: neutral

Tune: neutral

Tissue State

Dry atrophy as in weakness,  emaciation, and structural degradation of a tissue due to lack of nourishment.

Heat excitation specifically in the nervous system when it is stuck in a sympathetic (fight or flight) response. 

Wind excitation tissue state when muscle tension manifests as secondary to mental stress.

Pharmacology

Polysaccharides – a wide range of bioactivity, including anti-inflammatory, hypoglycemic, antiulcer, antitumor, and immunostimulatory effects

Peptidoglycans –  Bioactive protein-bound polysaccharides or glycopeptides with immunomodulating and antiviral activities, specifically showing inhibitory effects against viruses like herpes simplex, antiviral.

Triterpenes – Over 100 triterpenes have been reported in G. lucidum, with more than 50 being unique to this fungus, such as ganoderic and lucidenic acids. These compounds are responsible for the mushroom’s characteristic bitter taste

Proteins – These include LZ-8 (an immunosuppressive protein), ganodermin (an antifungal protein), and various antioxidant peptides

Lectins: A glycoproteins that bind carbohydrates and are involved in immune system functioning

Nucleosides and Nucleotides: Compounds such as adenosine and guanosine have been isolated and may contribute to medicinal effects like delaying blood clotting

Actions

Foundational actions are associated with the energetic pattern and can be experienced viscerally in the body.

Reishi’s foundational action is bitter. The triterpenoids in Reishi are the bitter principle here – they’re what gives it that characteristic bitter taste. Bitters primarily address stagnation and heat/excitation tissue states. They work by stimulating secretions and movement throughout the body, reducing excess excitation, and stimulating the vagus nerve.

Primary actions relate to organs, systems, or tissues.

• Immune modulating
• Nervine trophrestorative
• Adaptotegen
• Liver active
• Cardiovascular tonic

Secondary actions imply an end result without specifying energetics or the system affected.

• Anti-viral
• Anti-oxidant

Organ affinity

• Nervous system
• Immune system
• Cardiovascular system
• Liver

Clinical Pattern

Immune Modulating 

Reishi (Ganoderma lucidum) acts as a potent immunomodulator, capable of both stimulating and balancing the immune system through its diverse bioactive components. Its effects are primarily driven by polysaccharides (especially β-glucans), triterpenoids, and peptidoglycans, which influence both innate and adaptive immunity.

Reishi can help maintain homeostasis. While polysaccharides generally stimulate the immune system, triterpenoids often exhibit anti-inflammatory effects by inhibiting excessive production of inflammatory mediators. 

A quick tour of the adaptive immune system

The adaptive immune system is slow to respond to pathogens but highly specific and efficient. It is made of two main pathways: B cells and T cells. Reishi affects mostly T cells, so let’s focus on them.

T cells are born in the bone marrow, but finish their training in the thymus, where the immune system decides what type of T cell they will become. T cells can become:

• T helper 1 immune cells respond to viral or bacterial infections inside cells.
• T helper 2 immune cells respond mostly to allergens and parasites in the extracellular matrix, the gel like space where cells swim.
• T helper 17 cells are pro-inflammatory immune cells.
• T reg cells are like a fire extinguisher; they suppress the other T cells.
• T cytotoxic cells target damaged cells or cancer cells.
  

T-Cell Regulation

A clinical trial suggests that reishi increases total T lymphocytes and adaptive immune cells, indicating an overall strengthening of the body’s secondary line of defense against pathogens. But, and here it is where it gets interesting, reishi doesn’t increase all T cells equally; instead it creates an adaptive response by increasing some while suppressing others.

Let’s take a closer look

Reishi can help reduce inflammation by prioritizing Treg cell production over Th17 cells, potentially reducing the risk of autoimmune diseases and chronic inflammation.

The β-glucans from reishi can promote Th1 production at the expense of Th2 (allergen response and systemic autoimmunity) and Th17 (proinflammatory). At the same time, reishi was found to have a mast cell-stabilizing effect on the immune system. Overall, reishi suppresses allergic reactions and inflammation.

Increased Defense via Cytotoxic T Cells, the “special forces” of the immune system that directly interact with and destroy target cells, such as infected cells or cancerous cells.

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Cardiovascular conditions

Reishi (Ganoderma lucidum) is believed to influence the cardiovascular system through three pathways:

• Antioxidant effect
• Managing metabolic risk factors
• Blood pressure regulation

Antioxidant affect

The antioxidant properties of reishi are due to its polysaccharides, glycoproteins, triterpenes, amino acids, and phenolic compounds, which can donate hydrogen and electrons or combine with free radicals. Additionally, reishi’s polysaccharides have been shown to reduce lipid peroxidation and enhance glutathione peroxidase activity.

Triterpenes, an important bioactive compound in reishi, play a preventive role in the cardiovascular system by reducing inflammation and oxidative stress. Reishi contains various bioactive compounds, such as polysaccharides and peptides, that may prevent cardiovascular conditions by protecting endothelial cells in the blood vessels.

Managing metabolic risk

Reishi was found to help the body’s glucose metabolism by blocking the enzyme (HMG-CoA reductase) that breaks down carbohydrates in the small intestines, therefore slowing down glucose absorption.  At the same time, reishi increases cell sensitivity to insulin, which allows them to take sugar out of the blood and use it for energy instead of letting it build up.

In an animal study, reishi was found to have a protective effect on β cells in the pancreas, which produce insulin. Chronic pancreatitis is a progressive inflammation of the pancreas that leads to fibrosis and tissue destruction. Patients with chronic pancreatitis often suffer from abdominal pain, diarrhoea, jaundice, weight loss, and a tendency to diabetes caused by the destruction of β cells. 

Oxidative stress plays a critical role in pancreatitis. Also, oxidative stress disrupts gut epithelial integrity and the balance of gut bacteria, leading to metabolic conditions. The polysaccharides in reishi were found to reduce oxidative stress and promote immune-modulating gut bacteria, thereby improving pancreatic and overall metabolic health. 

Blood pressure regulation

An animal study suggests that reishi can reduce blood pressure at the same rate as losartan, a prescription medication used to treat high blood pressure. Unlike losartan, reishi significantly increases cerebral blood flow and cortical metabolic activity, shifting the balance of inhibitory and excitatory neurotransmitters toward excitation, promoting learning, memory consolidation, neuroplasticity, and cognitive function.

ACE (angiotensin converting enzyme) controls blood pressure by constricting arteries and increasing water retention. ACE inhibitors suppress the production of the ACE enzyme, therefore lowering blood pressure. The alcohol extract of reishi (triterpenoid-rich) was found to show stronger ACE inhibition than the water extract (polysaccharide-rich).

A meta-analysis of 358 animal studies found that reishi lowered triglycerides, total cholesterol, LDL, HDL, and VLDL levels.

Mental disorders

People who struggle with MDD (Major depressive disorder) experience sadness, less motivation, isolation, self-harm ideation, and more. A mental condition, MDD, can disrupt work, school life, and relationships. At least one-third of patients have treatment-resistant depression, which means they don’t respond to SSRIs.  

An animal study suggests that reishi appears to be directly addressing the neuroinflammatory component of depression at multiple levels. An injection of reishi polysaccharides produced a rapid, robust antidepressant effect in mice that lasted for 5 days. 

At the same time, the researchers observed a reduction in proinflammatory cytokines (↓ IL-1β, ↓ TNF-α) and an increase in anti-inflammatory cytokines (↑ IL-10), as well as Brain-derived neurotrophic factor ↑ BDNF which is typically low in depression. 

A couple of studies I read suggest that by lowering inflammation, reishi has a neuroprotective effect upon the brain that can influence degenerative conditions, depression, anxiety, and pain perception.  

Cancer

A meta-analysis of five randomized controlled trials to determine if Reishi could improve survival rates, enhance immune system response, or boost the quality of life for patients undergoing conventional cancer therapies. While the evidence suggests that the mushroom may serve as a beneficial adjunct to chemotherapy and radiotherapy by stimulating protective T-lymphocytes and increasing tumor response, the authors emphasize that it is not a replacement for conventional medicine.

Preparation and dosage

Reishi contains two main pharmacologically distinct groups of compounds that require very different extraction methods. 

Decoction

Polysaccharides, especially beta-glucans, are immune-modulating and anti-inflammatory. These are water soluble and will extract best in a slow decoction, 1-8 hours before straining. You can then preserve the decoction in 25% A

Dosage: 6-8 ounces three times a day

Ethanol extract

Triterpenoids, mainly ganoderic acids, are bitter compounds that reduce inflammation associated with allergic reactions by inhibiting the COX-2 pathway and stabilizing mast cells. The Triterpenoids also have neuroprotective, antidepressant, and anxiolytic effects. These are extracted best in alcohol. 

Dried mushroom, 1:5, 75% alcohol

Dosage: 2-8ml three times a day

Tea powder concentrate

Tea powder concentrate is a product made by decoding reishi for hours, straining the liquid, and reducing it to a highly concentrated tea, which is then dried into powder. You get standardized polysaccharides content, usually 30-50% polysaccharides, 10-30% beta-glucans specifically, and only minimal triterpenoids. The label on the product should indicate concentration as pounds of dried mushroom → 1 pound of powder.

Dosage: for a 5:1 concentration, 1 gram twice a day. For higher ratios (10:1, 20:1), which are more concentrated, use smaller doses. 

Safety

Some sources suggest liver injury due to reishi ingestion. Avoid in liver disease.

Avoid with immunosuppressant therapies, such as in organ transplants.

People with autoimmune conditions should use reishi with caution and with the support of an herbalist. A gentle use after building a balanced immune system can be beneficial; if the immune system is unbalanced, reishi can trigger an autoimmune flare. 

 Recipes For Remedies

By making a double extract you are extracting both the polysaccharides that are immune modulating and the triterpenoids that have neuroprotective, antidepressant, and anxiolytic effects.