Just a little housekeeping before we get into today’s deep dive on Reishi:
1. Herbal consultations and mentorship are officially open!
If you’re looking for personalized support on your herbal journey, whether you’re just starting out or hoping to go deeper, I’m now offering 1:1 consultations and mentorship (perfect for those looking to learn about more about herbalism!). You can check out all the details here:
2. I’ll be collaborating with some amazing voices in the herbal space.
To expand the conversation and offer more diverse perspectives, I’m teaming up with a few other publications here on Substack. First up is an article on mushroom identification and foraging that pairs beautifully with this post. Stay tuned. You’re going to love it.
3. PDF materia medicas are on the way, I promise.
If you’re a member of The Buffalo Herbalist Community, your printable Reishi monograph and study materials will be included in a separate post. I know I said that last time (guilty), but it’s worth the wait. I’m putting together a full medicinal mushroom lecture, similar to the one we did on the lymphatic system. You’ll get the PDF, the lecture, and a curated list of study resources within the next week or so.
Now, let’s step into the world of Reishi, the ancient, bitter, beautiful mushroom that continues to teach us what it means to heal slowly and deeply.
Reishi
You’ve probably seen the name—even if you’re not entirely sure what it does. It’s slipped into mushroom coffee blends, added to calming tinctures and teas, and tucked inside wellness gummies that promise everything from sharper focus to deeper sleep.
But long before Reishi became a buzzword in the wellness world, it was revered as something sacred.
Known as Ganoderma lucidum, this glossy, deep reddish-brown mushroom with a lacquered surface has a rich history of use across China, Japan, and other parts of Asia. The Latin lucidum means “shiny” or “brilliant,” a nod to its varnished sheen. Its names in traditional cultures, Lingzhi in Chinese and Reishi or Mannentake in Japanese, point to something far more profound than aesthetics.
In classical Chinese medicine, Lingzhi is called the “Mushroom of Immortality” and the “Herb of Spiritual Potency.”
It was believed to nourish the spirit (Shen), strengthen the heart, tonify Qi, and prolong life. For over 2,000 years, it has been documented in ancient materia medicas, from the Shen Nong Ben Cao Jing to the Ben Cao Gang Mu, China’s first true pharmacopoeia.
This wasn’t a mushroom for the masses. Wild Reishi was rare, growing high in misty mountain forests—or, according to legend, in the celestial homes of the immortals. For centuries, it was reserved for emperors, scholars, and sages. It symbolized not just health and longevity, but divine favor and inner cultivation.
Interestingly, early texts describe not one, but several types of Lingzhi, each with a different color and energetic correspondence. In the Ben Cao Gang Mu, five major types were recorded: red, black, yellow, white, and purple.
These colors were linked to the five elements and their associated organ systems. Red Reishi corresponded to the heart, black to the kidneys, yellow to the liver and gallbladder. While not all color associations match perfectly with what we know about modern Ganoderma species, some have held up over time, especially in terms of traditional usage.
For example, black Reishi (G. sinense) was traditionally used for kidney-related symptoms, including chronic fatigue and even deafness. Red Reishi remains the most studied and widely used today, particularly for immune and cardiovascular support, as well as its role in calming the nervous system. These color-coded distinctions likely reflected real chemical differences in species growing in different regions, long before taxonomy or DNA sequencing were available to verify them.
Modern science has since revealed that what we call “Reishi” includes multiple Ganoderma species with overlapping but distinct phytochemical profiles. Differences in triterpene content, beta-glucan branching, and other compounds may explain why certain varieties were used for specific conditions. And while the taxonomy is now more refined, the spirit of those traditional classifications still echoes in how we use the mushroom today.
Whether you’re reaching for Reishi to ease stress, support your immune system, or reconnect with something ancient, this is a fungus that invites depth. In this post, we’ll explore what Reishi actually does in the body, what science has begun to confirm, and how to work with it in a way that respects both tradition and evidence.
Let’s begin.
Reishi mushroom
Reishi in Context: What It Is, How It Grows, and Why That Matters
Reishi isn’t your typical mushroom.
You won’t find it tossed into a stir fry or sautéed with garlic. It’s a hard, woody polypore that grows like a shelf from dead or dying hardwood trees, with a glossy, reddish surface that looks lacquered by nature herself. The species most commonly used medicinally is Ganoderma lucidum, though even that name can be misleading.
Taxonomically, things get a little messy. The Ganoderma genus includes over 200 species, and G. lucidum is just one of them. Because the shape, color, and texture of the fruiting body can vary depending on where and how it grows, there’s been a long history of mislabeling and synonym confusion.
What’s sold as “Reishi” might actually be G. tsugae, G. sinense, or another look-alike with similar but not identical compounds. That’s not necessarily bad, but it is important to be aware of, especially when quality and standardization matter.
While wild Reishi still exists, it’s rare.
In the past, it was a mushroom for emperors and alchemists, partly because it was so hard to find. Today, most of what we consume is cultivated—often on sawdust, grain, or hardwood logs in hot, humid conditions that mimic its native environment. This cultivation revolutionized accessibility, but it also introduced some nuance. Fruiting body, mycelium, spores, or culture broth? The part used, and how it’s grown and processed, can significantly affect the final product’s chemical profile.
For example, mycelium grown in liquid culture tends to be rich in extracellular polysaccharides, while log-grown fruiting bodies often contain higher levels of triterpenes, like ganoderic acids.
And while some companies promote spore-based products, especially broken or "cracked" spores for improved bioavailability, there’s ongoing debate about how much additional benefit they actually offer.
This is why not all Reishi supplements are created equal. Whether you’re holding a capsule, a tincture, or a chunk of dried mushroom, it helps to know what part of the mushroom you’re using and how it was grown. This sets the stage for the next layer of understanding: what these different compounds actually do in the body.
But first, let’s peek inside the chemistry.
G. tsugae
Inside the Mushroom: What Makes Reishi Work
If you’ve ever taken a bite of Reishi (not that I recommend it), you’d understand why it’s not found in soups or sautés. It’s woody, bitter, and unyielding. But beneath that bark-like exterior is a complex matrix of medicinal compounds—polysaccharides, triterpenes, peptidoglycans, and minerals—all working together to influence the body in subtle, multi-system ways.
Let’s take a look at the major players.
Polysaccharides, especially beta-glucans, are among the most studied. Found in the fruiting body, spores, and mycelium, these long-chain sugars influence immune function, modulate inflammation, and support resilience in the face of chronic infections, fatigue, or stress. Their structures vary widely, which can make them hard to standardize, but that diversity is part of what gives Reishi its broad-spectrum adaptability.
Triterpenes are responsible for Reishi’s signature bitterness—and many of its more targeted effects. These fat-soluble compounds support cholesterol metabolism, reduce inflammation, protect the liver, and even help modulate histamine responses. More than 100 different triterpenes have been identified in Ganoderma lucidum, and their concentrations vary depending on species, growing conditions, and extraction method. Because they’re alcohol-soluble, you’ll often find them most concentrated in dual-extract tinctures.
Peptidoglycans and glycoproteins might not get as much spotlight, but they’re important immunological players. These molecules seem to act as modulators, offering gentle balancing effects for both underactive and overactive immune responses.
Minerals and additional compounds round out the picture. Reishi contains potassium, calcium, selenium, and small amounts of germanium, a trace element sometimes linked to immune health. Other notable constituents include ganodermin (an antifungal protein), ergosterol (a vitamin D precursor), immune-active lectins, blood sugar-regulating peptides, and long-chain fatty acids with possible anticancer properties.
In short, Reishi doesn’t rely on a single compound or a magic bullet. Its strength lies in synergy—a layered, interdependent chemistry that mirrors how it works in the body: steadily, intelligently, and with wide-reaching support.
Reishi
What the Research Says: Reishi’s Role in Modern Health
For centuries, Reishi was taken on faith, used to strengthen the spirit, nourish Qi, and ward off disease. But today, scientists are asking a different question: what does this mushroom actually do inside the body? While most modern studies are still preclinical, many findings echo what traditional herbalists already sensed. Reishi doesn't work on just one pathway. It acts more like a conductor, supporting multiple systems and nudging the body toward balance.
Much of the research we have comes from cell studies and animal models, with only a few small human trials. So while Reishi is not a miracle cure, it remains one of the most promising herbal supports for immunity, inflammation, metabolic regulation, and chronic disease resilience.
Cancer Support: Not a Cure, But a Companion
Reishi is widely studied for its role in oncology, not as a standalone treatment, but as a companion to conventional care. Its triterpenes and polysaccharides have been shown to trigger apoptosis in cancer cells and inhibit the growth of new blood vessels that tumors rely on to spread. In animal models, Reishi reduced tumor size and slowed metastasis, especially when combined with chemotherapy drugs like cisplatin.
In small human trials, a patented polysaccharide extract called Ganopoly showed promising immune-enhancing effects. Patients with advanced cancers had increased NK cell activity and higher levels of cytokines like IL-2 and interferon-gamma. Many also reported an improvement in quality of life. While these studies were limited in scope and came from a single research group, the findings suggest that Reishi may help the body recover during treatment and tolerate it more easily.
Immune Modulation: More Than Just a Boost
Reishi doesn’t simply stimulate the immune system. It modulates it, supporting a balanced response rather than pushing it into overdrive. Polysaccharides in Reishi enhance both innate and adaptive immunity, helping to activate macrophages, natural killer cells, and lymphocytes. They also influence important signaling molecules like IL-6, IL-2, and TNF-alpha. What’s especially compelling is that Reishi may help regulate excessive immune activity too, which is why it’s sometimes considered useful in autoimmune conditions. It adapts to what the body needs.
Antioxidant Actions and Cellular Protection
Reishi’s antioxidant capacity is one of its most researched properties. Its polysaccharides, triterpenes, and protein-bound polysaccharide complexes help scavenge free radicals and protect DNA from oxidative stress. These effects are relevant in conditions linked to inflammation, aging, and cellular damage. Some extracts seem to behave as antioxidants at lower doses and as mild pro-oxidants at higher ones. This dual action might help explain how Reishi can protect healthy cells while enhancing the effect of chemotherapy in cancer cells.
In a small human study, Reishi was shown to increase antioxidant capacity in the blood within 90 minutes of ingestion. While the long-term clinical significance of this is still unclear, it supports Reishi’s reputation as a protective, regulatory herb at the cellular level.
Antiviral and Antibacterial Effects
Reishi is not a conventional antimicrobial, but it has shown activity against several viruses and bacteria in laboratory studies. Extracts have demonstrated inhibitory effects on herpes simplex viruses, hepatitis B virus, and even HIV-1 protease. The mechanism appears to involve interference with viral replication or attachment to host cells.
In small clinical reports, high-dose Reishi extracts reduced pain and supported healing in elderly patients with shingles. Animal studies have shown increased survival in mice infected with E. coli, and in vitro work has shown antibacterial activity against several gram-positive strains. Although we still have a lot to learn about how these compounds work in the human body, the evidence suggests Reishi could be a helpful partner in immune defense, particularly during or after infections.
Metabolic and Blood Sugar Support
Reishi has traditionally been used to support blood sugar regulation, and modern studies support this idea. In diabetic animal models, compounds like ganoderans A, B, and C helped reduce blood glucose levels, improved insulin sensitivity, and supported antioxidant status in key tissues.
In a human trial, patients with type 2 diabetes were given Ganopoly at a dose of 1,800 milligrams three times a day for 12 weeks. Results showed lower fasting glucose and HbA1C levels, pointing to better long-term glucose control. While this doesn’t make Reishi a substitute for conventional diabetes treatments, it does suggest that it may have a supportive role in metabolic health.
Liver and Digestive Health
In traditional herbalism, Reishi has long been seen as a liver tonic, and modern research largely agrees. Animal studies show that it can reduce liver enzymes, improve antioxidant enzyme activity, and protect liver tissue from chemical and alcohol-induced damage. Some of these effects appear to be linked to ganoderic acids, which help prevent toxicity at the enzymatic level.
Even more fascinating, several studies suggest that the broth used to grow Reishi mycelium, without the mushroom itself, can offer protective effects on liver function. Reishi may also support gut healing. In models of gastric ulcers, polysaccharide fractions helped speed up healing and restore protective mucus and prostaglandin levels.
Closing Thoughts on the Research
Reishi is not a one-note herb. It operates like a systems thinker—calming where there’s excess, restoring where there’s deficiency, and subtly regulating the complex terrain of the human body. While more rigorous human trials are needed, the early data paints a compelling picture: Reishi is not only safe for most people but may offer wide-ranging benefits when used thoughtfully and consistently.
How to Work with Reishi: Choosing, Preparing, and Dosing This Ancient Fungus
Reishi may be one of the most revered medicinal mushrooms in history, but what you find on the shelf today isn’t always the same mushroom that once grew on misty cliffs and gnarled forest trunks.
If you’re reaching for Reishi as part of your daily herbal routine, the form, species, and preparation matter. The modern herbal marketplace has made it surprisingly easy to buy Reishi, but that convenience also comes with a lot of confusion. Not all Reishi is the same—not by species, not by preparation, and certainly not by potency.
There are at least four species of Ganoderma commonly sold under the Reishi name: G. lucidum, G. lingzhi, G. sinense, and G. sichuanense. Chemically, they are not identical. While they may share overlapping benefits, they haven’t all been tested side by side in humans. The species most commonly associated with traditional “red Reishi” is G. lingzhi, which is what you'll find labeled in many Chinese herb shops. However, many products still list G. lucidum on the label, and others may contain different species entirely. Without DNA verification or chromatography testing, it’s hard to know exactly what you’re getting.
Look for transparency in labeling. If a product is high quality, the manufacturer should be able to tell you not only which species was used, but also whether it has been verified through DNA analysis and tested for active compounds like beta-glucans and triterpenes. If you're unsure, it’s worth calling the company and asking. That one step can tell you a lot.
G. sinense - Black Reishi
What You’re Actually Taking—and What to Look For
Most commercial Reishi products are made from either the fruiting body (the actual mushroom) or mycelium (the root-like structure grown on grain). Both have benefits, but they’re not interchangeable.
Fruiting bodies tend to contain more triterpenes and fungal beta-glucans—the compounds most associated with immune, liver, and antioxidant support. These are what you’ll find referenced in most clinical studies and traditional texts. Mycelium, on the other hand, is faster and cheaper to grow. It can still be beneficial, especially if grown in liquid culture without grain, but the potency can vary significantly. Grain-based mycelium may contain more starch than mushroom unless it’s been tested and standardized.
Bitterness can offer a clue. Reishi’s intense bitterness comes from its triterpene content. So, while not all potent products are bitter, and not all bitter products are potent, a complete lack of bitterness, especially in a product that hasn’t been tested, might suggest it’s mostly filler.
As for dosage, it depends on your goal. For therapeutic support—such as with fatigue, insomnia, or chronic immune dysregulation—2 to 3 grams of dried fruiting body powder twice a day is often recommended, usually as a decoction or tea. For general wellness and maintenance, 1 to 2 grams daily is usually sufficient.
Tinctures can be a good option, especially dual extracts that combine hot water and alcohol to capture the full range of active compounds. Always check that the product lists beta-glucan content, ideally between 15 and 35 percent.
Much of the world’s Reishi is grown in China, where the cultivation traditions are long-standing and the labor costs are lower. In the United States, most Reishi products are mycelium-based for practical reasons. This doesn’t necessarily mean they’re inferior, but it does require closer scrutiny. If you’re sourcing raw slices, powders, or teas, prioritize suppliers that test for species identity, heavy metals, and pesticide residues.
Reishi is not a trendy superfood—it’s a slow, grounding, deeply adaptive ally. Its effects are subtle but profound when taken consistently and with intention. Whether you sip it in tea, blend it in a tonic, or take it in tincture form, the real power of Reishi lies in choosing it with care and taking it with trust.
Reishi asks something of us that many herbs do not: patience. Its medicine is not fast or flashy. It doesn't numb, override, or stimulate. Instead, it nudges gently, persistently bringing the body back to center over time.
In a culture hungry for quick fixes, Reishi reminds us of the long path.
The sacred path.
The kind that builds resilience not just in the body, but in the spirit. Whether you approach it through tradition or science, or both, Reishi remains a profound teacher of balance: rooted, bitter, and utterly wise.
If you found this article insightful, please consider sharing it with someone who could use a little grounding in their life. You can also like, comment, or subscribe to support more writing like this. Paid subscribers get access to monographs, PDFs, and deeper discussions inside our herbal community.
Until next time,
-Agy | The Buffalo Herbalist
Bibliography
Wachtel-Galor, S., Yuen, J., Buswell, J. A., & Benzie, I. F. F. (2011). Ganoderma lucidum (Lingzhi or Reishi). Herbal Medicine - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK92757/
Hobbs, C. (2021). Christopher Hobbs’s Medicinal Mushrooms: The Essential Guide: Boost Immunity, Improve Memory, Fight Cancer, Stop Infection, and Expand Your Consciousness. Storey Publishing, LLC.
