Reishi Mushroom: What the Mushroom of Immortality Actually Does

In ancient China, Reishi was reserved for emperors.

It was called Lingzhi, two characters meaning "herb of spiritual potency," and for centuries it was made rare by a law that allowed only the ruling class and their physicians to access it. Court doctors used it to calm the spirit, strengthen the heart and extend life. Artists painted it into palace murals as a symbol of health, fortune and divine protection.

Reishi has earned this mythological status through millennia of accumulated observation by people who recorded its benefits with care and precision.

The Daoist Inheritance

Reishi did not begin with the emperors. It began with the Daoists.

In the Shennong Ben Cao Jing, the foundational text of traditional Chinese medicine compiled around 200 CE, Reishi was placed in the highest of three categories: the superior herbs, those considered non-toxic and suitable for long-term use. Of Lingzhi, Shennong 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."

Daoist monks and mountain hermits sought Lingzhi in remote forests, sometimes spending weeks in the search. They used it as what they called a "shen tonic," a preparation for the spirit, believing it cultivated clarity of consciousness and harmony between the mind and the body. The path to stillness required a body that did not resist it. Reishi, they found, helped remove the resistance.

Two thousand years of that kind of attention is what separates Reishi from other natural ingredients.

What Reishi Is

Reishi (Ganoderma lucidum) is a large, flat mushroom with a lacquered, deep red-brown surface, almost wooden in appearance. It grows on dead or dying hardwood trees throughout East and Southeast Asia, producing slowly, year after year, in the same places.

It is not a mushroom you eat. Its texture is dense and bitter, and its active compounds are best drawn out through slow hot-water decoction or alcohol extraction. Traditional practitioners would simmer Reishi for hours, producing a dark, concentrated tea that patients took over months or years.

The compounds responsible for its effects are beta-glucans, a family of polysaccharides, and triterpenes. Both are concentrated in the fruiting body. Both require extraction to become available to the body.

What It Does

Reishi works across multiple systems at once. This breadth is what traditional Chinese medicine valued most, and what modern pharmacology has studied most extensively. The term used in contemporary research is "adaptogenic": an agent that helps the body respond to stress and imbalance more efficiently, without forcing any single pathway into overdrive.

The nervous system. Reishi triterpenes have a measurable calming effect on the central nervous system. Studies show they reduce activity in the brain regions associated with anxiety and hyperarousal. [1, 2] Most people who use Reishi consistently describe the effect not as sedation, but as the absence of unnecessary tension. Evenness, rather than stillness.

Sleep. Reishi polysaccharides have been shown to increase total sleep time, improve sleep quality and reduce the time taken to fall asleep. [3] The mechanism passes through the gut microbiome: Reishi modulates intestinal bacteria that influence the production of serotonin and melatonin. When the gut is in better balance, sleep deepens.

The immune system. Reishi's beta-glucans bind to receptors on immune cells, primarily macrophages and natural killer cells, activating and strengthening their responsiveness without triggering inflammation. [4] This is a calibrating effect rather than a stimulating one. The immune system is helped to regulate itself.

Allergic responses. Ganoderic acids isolated from Reishi have been shown to inhibit histamine release from mast cells, the immune cells responsible for the acute symptoms of hay fever, skin reactions and food sensitivities. [5] In a documented case, a hay fever patient supplementing with Ganoderma experienced a marked decrease in drowsiness, itchiness and sneezing within three to four days, and after ten days was able to mow the grass without significant discomfort. More recent research has confirmed that Reishi modulates the immune pathways underlying allergic inflammation. [6]

Respiratory support. Traditional Chinese medicine used Reishi specifically for the lungs: for chronic cough, shortness of breath and what practitioners described as "lung deficiency." Clinical research has supported this, with studies finding Reishi extract effective as a supportive treatment for chronic bronchitis, reducing symptoms and improving respiratory function in patients. [7]

Inflammation. Reishi triterpenes have demonstrated anti-inflammatory activity comparable in some studies to pharmaceutical agents, without the associated side effects. [8]

A Tonic and a Remedy

The distinction between a tonic and a remedy is a useful one, but it should not be overstated.

A tonic is taken continuously, over months and years, to sustain the body's capacity to function. Reishi is genuinely this: a medicine that builds its effect gradually and rewards long-term use.

But Reishi is also capable of meaningful acute intervention. For someone with seasonal allergies, respiratory inflammation or acute stress, Reishi can offer real relief, not only over weeks of cumulative use but in shorter periods of targeted supplementation. The Daoist monks who used it knew both of these qualities. So did the court physicians who prepared it for emperors managing the pressures of complex lives.

The body is not always in need of gradual recalibration. Sometimes it needs direct support. Reishi offers both.

How POTENT: Uses It

Our Reishi extracts are made in our Chiang Mai lab from organically grown fruiting bodies. We use ultrasonic-assisted extraction combined with hot water and alcohol, so that both the beta-glucans and the triterpenes are fully captured and bioavailable in every bottle. Every batch is third-party tested for purity and potency.

Our Reishi Elixir is for daily use, taken directly or blended into a warm drink. Our Reishi Syrup is for those who prefer to fold it into their existing routines.

More on Reishi's traditional history and compound profile is on our dedicated Reishi page.

If you are in Chiang Mai, you can drink Reishi as CALM tea at the POTENT: Mushroom Tea House, brewed with our extract.

What Two Thousand Years of Observation Looks Like

The Daoist monks who climbed mountains searching for Lingzhi were practitioners of a rigorous tradition that valued sustained observation, precise language and careful differentiation between what was felt and what was imagined.

What they wrote about Reishi, and what the physicians recorded over centuries, is now being confirmed in clinical trials and laboratory conditions. The mechanisms are different from what the Daoists understood, but the effects they described are not.

Reishi does not cure ailments. It helps the body to sustain without being diminished. That is a unique and rare quality.

Frequently Asked Questions

When should I take Reishi? Most people find it most useful in the evening, aligned with the body's natural move toward rest. If anxiety or respiratory symptoms are a primary concern, use across the day can also help.

How long does Reishi take to work? Most people notice improved sleep quality within one to two weeks. Broader effects, including nervous system calm and immune regulation, build over four to eight weeks of consistent daily use. For acute allergy support, some people notice relief within days.

Is Reishi safe to take every day? Yes. Reishi has a long, well-documented history of safe daily use. It is non-toxic and does not create dependency.

Can I take Reishi alongside conventional treatment for allergies or respiratory conditions? Reishi can be used as a supportive measure alongside conventional treatment, and there is clinical evidence for its benefit in both. Consult your doctor if you are on anticoagulant medication or immunosuppressants before adding any new extract.

What does "mushroom of immortality" mean? Lingzhi (灵芝) translates as "herb of spiritual potency." The association with immortality in Chinese culture reflects observed effects on longevity and vitality over generations of use, recorded in some of the oldest medical literature in the world.

Where can I find Reishi extract in Thailand? POTENT: makes and sells Reishi elixirs and syrups from our Chiang Mai lab. We ship across Thailand. Begin here.

Sources

1. Tang W, et al. "A randomized, double-blind and placebo-controlled study of a Ganoderma lucidum polysaccharide extract in neurasthenia." Journal of Medicinal Food, 2005; 8(1): 53–58. https://doi.org/10.1089/jmf.2005.8.53

2. Wachtel-Galor S, et al. "Ganoderma lucidum (Lingzhi or Reishi): A Medicinal Mushroom." In: Benzie IFF, Wachtel-Galor S, editors. Herbal Medicine: Biomolecular and Clinical Aspects, 2nd ed. CRC Press, 2011. https://www.ncbi.nlm.nih.gov/books/NBK92757/

3. Cui XY, et al. "Extract of Ganoderma lucidum prolongs sleep time in rats with caffeine-induced insomnia." Journal of Ethnopharmacology, 2012; 139(3): 796–800. https://doi.org/10.1016/j.jep.2011.12.020

4. Lin ZB. "Cellular and molecular mechanisms of immuno-modulation by Ganoderma lucidum." Journal of Pharmacological Sciences, 2005; 99(2): 144–153. https://doi.org/10.1254/jphs.crj05008x

5. Bhimra A, et al. "Suppression of inflammatory and allergic responses by pharmacologically potent fungus Ganoderma lucidum." Recent Patents on Inflammation and Allergy Drug Discovery, 2014; 8(2): 104–117. https://pubmed.ncbi.nlm.nih.gov/24948193/

6. Liu Y, et al. "Ganoderma modulates allergic asthma pathologic features via anti-inflammatory effects." PubMed, 2022. https://pubmed.ncbi.nlm.nih.gov/35026480/

7. Wang Y, Liu Y, Liu Z. "Clinical study of Ganoderma lucidum in the treatment of chronic bronchitis." Chinese Journal of Integrated Traditional and Western Medicine, 2004; 24(4): 347–350. https://pubmed.ncbi.nlm.nih.gov/15381947/

8. Jin X, et al. "Ganoderma lucidum (Reishi mushroom) for cancer treatment." Cochrane Database of Systematic Reviews, 2016; 4: CD007731. https://doi.org/10.1002/14651858.CD007731.pub3

Related reading: Lion's Mane: Clarity and the Focused Mind | Cordyceps: Energy from the Himalayas

POTENT: makes organic, third-party tested mushroom extracts in Chiang Mai, Thailand. Every product is crafted to be felt.