Reishi
Ganoderma lucidum
Known for over 2,000 years as the “Mushroom of Immortality” — today's go-to adaptogen for calm and immune balance.
1 Main Focus: Calm, Stress Relief & Immune Balance
Reishi (Ganoderma lucidum) is one of the most legendary mushrooms in the world, often called the "Mushroom of Immortality" in ancient Chinese texts. Today it's best known as an adaptogen — something people take to help the body handle everyday stress — and for its long-studied role in immune balance.
2 What Is Reishi?
Reishi is a glossy, reddish-brown shelf mushroom that grows at the base of trees, especially plum and oak. Unlike Lion's Mane or Shiitake, it's rarely eaten as food — it's woody and bitter — so it's almost always consumed as a tea, extract, tincture, or capsule instead.
Reishi has been used in East Asian wellness traditions for over 2,000 years, and its Chinese name, Ling Zhi, translates roughly to "spirit plant" or "herb of spiritual potency."
3 How It May Work
Reishi's most-studied compounds are triterpenes (specifically ganoderic acids) and polysaccharides, particularly beta-glucans. Triterpenes give Reishi its distinctly bitter taste and are believed to interact with the body's stress-response systems, while its polysaccharides are studied for their role in modulating immune cell activity.
4 Natural Compounds
Triterpenes (Ganoderic Acids)
Give Reishi its bitter taste; studied for interactions with stress and inflammation pathways.
Beta-Glucan Polysaccharides
The most researched compound class in Reishi; linked to immune cell modulation.
Peptidoglycans
Complex compounds combining protein and sugar chains, studied alongside Reishi's polysaccharides.
Antioxidants
Support the body in managing everyday oxidative stress.
5 What Human Research Says
Reishi is one of the most-studied medicinal mushrooms on earth, with a large body of laboratory and animal research behind its immune and stress-related compounds. Human clinical trials exist too, particularly around immune markers and general well-being, but results are mixed and often involve small sample sizes or extract concentrations far higher than what's found in a typical daily serving.
6 Traditional Use & History
Reishi appears in the earliest Chinese materia medica texts, some dating back over two millennia, where it was classified as a "superior" herb — meaning it was believed safe for long-term, everyday use rather than only for treating specific ailments. It was historically so rare in the wild that it was reserved for emperors and nobility before cultivation techniques made it widely available.
Reishi is generally well tolerated, though some people report mild digestive upset when first starting.
Because Reishi may interact with blood-thinning medication and blood pressure medication, talk to your doctor before use if you take either.
Not recommended without medical guidance if pregnant, nursing, or scheduled for surgery.
These statements have not been evaluated by the FDA. Reishi is not intended to diagnose, treat, cure, or prevent any disease.
8 Common Questions
Is Reishi psychoactive?
No. Reishi is a legal, non-psychoactive mushroom with no psilocybin content.
Why does it taste so bitter?
The same triterpene compounds studied for Reishi's effects are also what give it a strong, bitter taste — which is why most people prefer it in capsule, gummy, or tincture form rather than as a raw tea.
Is Reishi the same as "immortality" in a literal sense?
No — the name is a historical nickname reflecting how highly it was regarded, not a literal claim. 'MERICA makes no such claim either.
How is it usually taken?
'MERICA plans to offer Reishi as a gummy, capsule, and tincture — see our Format & Timing guide on the Science & Safety Hub.
Curious About the Others?
Every 'MERICA Mycology species gets the same deep-dive treatment — explore the full lineup or dig into the compounds and research behind them all.
These statements have not been evaluated by the Food and Drug Administration. This information is educational and is not intended to diagnose, treat, cure, or prevent any disease. Always talk to your doctor before starting any new supplement, especially if you are pregnant, nursing, taking medication, or managing a health condition.