Reishi (Ganoderma lucidum) — The Mushroom of Immortality
Reishi mushroom (Ganoderma lucidum) has been used in East Asian medicine for over 2,000 years and is one of the most studied medicinal mushrooms. It contains over 400 bioactive compounds including triterpenes (ganoderic acids), polysaccharides (beta-glucans), and sterols. Modern research supports its immunomodulatory, anti-inflammatory, hepatoprotective, and potential anti-cancer properties.
Mechanism of Action
Reishi's beta-glucans activate macrophages, NK cells, and dendritic cells via Dectin-1 and TLR receptors, enhancing innate immunity. Ganoderic acids inhibit NF-κB, reduce TNF-α and IL-6, and have hepatoprotective effects via antioxidant pathways. Reishi also inhibits 5-alpha reductase (relevant for prostate health) and has mild adaptogenic effects on cortisol.
Human Trial Evidence
A 2016 Cochrane review found insufficient high-quality RCT evidence for cancer treatment but noted immune-enhancing effects. A 2012 Journal of Medicinal Food RCT showed reishi extract improved fatigue and quality of life in breast cancer patients. Multiple trials confirm immune-modulating effects. Evidence for cognitive and longevity effects is primarily preclinical.
Dosing Protocol
1–3 g/day of dried extract (standardised to 10–20% polysaccharides and 1–2% triterpenes). Dual-extraction products (water + alcohol) provide both polysaccharides and triterpenes. Best taken with meals. Effects on immunity typically seen after 4–8 weeks. Cycle use (8 weeks on, 2 weeks off) is common practice.
Safety & Contraindications
Generally well-tolerated. Mild GI effects, dry mouth, or dizziness possible. Rare: liver toxicity with powdered whole mushroom (not extract) at high doses. May potentiate anticoagulants (warfarin, aspirin) — monitor INR. Avoid in thrombocytopenia. Discontinue 2 weeks before surgery.