Reishi: What the Science Says
Ganoderma lucidum
Reishi has been used for centuries as a calming 'adaptogen.' Modern research focuses on its immune-modulating sugars (β-glucans) and its bitter triterpenoids.
What the research looks promising for
A solid trial found it eased fatigue and improved wellbeing in people with chronic fatigue, and small trials suggest mood and quality-of-life benefits. Lab work supports its immune effects.
Where the evidence is thin — or cautionary
The top-tier Cochrane review found Reishi is NOT proven as a stand-alone cancer treatment (only a possible add-on), and concentrated powders have, rarely, been linked to liver problems. Dose and quality vary widely.
Watch & listen
5 short, plain-language Reishi resources built from the studies below.
The research (5 studies)
Sorted strongest-evidence-first. Each shows a plain-language bottom line and how much weight it can bear. See the plain-language glossary →
The highest-quality evidence review found Reishi isn't proven as a stand-alone cancer treatment, but may help as an add-on by supporting the immune system and quality of life.
Jin, X., Ruiz Beguerie, J., Sze, D. M.-Y., & Chan, G. C.-F. (2012). Ganoderma lucidum (Reishi mushroom) for cancer treatment. Cochrane Database of Systematic Reviews, 6, CD007731.
In a trial of 132 people with chronic fatigue and weakness, Reishi for eight weeks improved fatigue and wellbeing more than a placebo — one of the strongest human results for Reishi.
Tang, W., Gao, Y., Chen, G., Gao, H., Dai, X., Ye, J., Chan, E., Huang, M., & Zhou, S. (2005). A randomized, double-blind and placebo-controlled study of a Ganoderma lucidum polysaccharide extract in neurasthenia. Journal of Medicinal Food, 8(1), 53–58.
Women with fibromyalgia who took Reishi for six weeks reported less depression and fatigue and better quality of life than those on a placebo.
Pazzi, F., Adsuar, J. C., Domínguez-Muñoz, F. J., García-Gordillo, M. A., Gusi, N., & Collado-Mateo, D. (2020). Ganoderma lucidum effects on mood and health-related quality of life in women with fibromyalgia. Healthcare, 8(4), 520.
A Reishi extract reduced depression-like behavior in rats and raised mood-related brain chemicals — early lab support for the idea that Reishi affects mood.
Matsuzaki, H., Shimizu, Y., Iwata, N., Kamiuchi, S., Suzuki, F., Iizuka, H., Hibino, Y., & Okazaki, M. (2013). Antidepressant-like effects of a water-soluble extract from the culture medium of Ganoderma lucidum mycelia in rats. BMC Complementary and Alternative Medicine, 13, 370.
The go-to scientific reference on Reishi — its biology, compounds, and immune and cancer-support evidence — while honestly flagging rare cases of liver toxicity from concentrated powders.
Wachtel-Galor, S., Yuen, J., Buswell, J. A., & Benzie, I. F. F. (2011). Ganoderma lucidum (Lingzhi or Reishi): A medicinal mushroom. In Benzie, I. F. F., & Wachtel-Galor, S. (Eds.), Herbal Medicine: Biomolecular and Clinical Aspects (2nd ed.). CRC Press/Taylor & Francis.
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