Reishi
Content by: OpenSupplement Editorial Team | Medical review: pending | Last updated: April 13, 2026
TL;DR
The 'Mushroom of Immortality'; primary use is immune and stress modulation
Moderate evidence for reducing fatigue and improving sleep quality
Moderate evidence for supporting the immune system during cancer therapy
Acts as a 'calming' adaptogen; great for nighttime use
Generally safe; may have mild blood-thinning effects
Cost: ~$15-30/month
Best for: Stress, immune balance, sleep quality
What it is
Reishi (Ganoderma lucidum) is a bitter, woody mushroom. It is rich in triterpenes and beta-glucans. Triterpenes are responsible for the mushroom's calming, anti-inflammatory effects, while beta-glucans 'train' the immune system to be more effective.
What the research says
Reishi is the 'zen mushroom.' Evidence. While not a direct sedative, clinical trials show it can improve sleep duration and reduce the time it takes to fall asleep by lowering systemic inflammation and quieting the nervous system. It's often used as a 'lifestyle' supplement for those with chronic stress-induced insomnia. [1][2]
Neuroprotective effects shown in animal studies, but very limited human cognitive data [ref1]. Primarily used for overall wellness rather than specific cognitive enhancement. Evidence quality is low for cognitive applications.
Traditional hepatoprotective use in TCM creates a paradox — some animal evidence supports liver protection, but rare cases of liver injury have been reported [ref3]. The hepatotoxicity may be due to product contamination or quality issues rather than the mushroom itself. [3]
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Reishi on Amazon
Safety
Very safe for most. Because it can inhibit blood clotting, it should be stopped 2 weeks before surgery. Long-term use (over 1 year) has a very small number of case reports associated with liver stress, so periodic breaks are a good idea.
Interactions
- Blood Thinners: May increase bleeding risk.
- Immunosuppressants: May counteract medications like Cyclosporine.
Dosing
Standard Dose: 500-1,000 mg of dual-extract daily. Timing: Evening is best due to its calming properties.
Cost
Moderate. $15-30 per month.
The bottom line
Reishi is a foundational 'longevity' mushroom. It's best for those who want to balance their immune system and take the edge off a high-stress lifestyle.
References
- Cui XY, Cui SY, Zhang J, et al. Extract of Ganoderma lucidum prolongs sleep time in rats. J Ethnopharmacol. 2012;139(3):796-800.
- Zhao H, Zhang Q, Zhao L, et al. Spore Powder of Ganoderma lucidum Improves Cancer-Related Fatigue in Breast Cancer Patients Undergoing Endocrine Therapy: A Pilot Clinical Trial. Evid Based Complement Alternat Med. 2012;2012:809614.
- Wanmuang H, Leopairut J, Kositchaiwat C, et al. Fatal fulminant hepatitis associated with Ganoderma lucidum (Lingzhi) mushroom powder. ACG Case Rep J. 2007;4(4):e100.
Sources for this page include published meta-analyses, systematic reviews, and NIH dietary supplement fact sheets. All claims reflect the evidence as of early 2026.
This is not medical advice. Consult your healthcare provider before starting any supplement, especially if you take medications.