Reishi (Ganoderma lucidum) is a woody fungus with over 2,000 years of use in East Asian medicine. Known traditionally as lingzhi, it has long been associated with longevity, immune resilience, and healthy aging.
If you've read our general guide to mushrooms, you'll already know that Reishi is most often associated with immune health and healthy aging. A lot of this comes from the unique compounds found within the mushroom itself.
Why Researchers Are Interested in Reishi
Like many medicinal mushrooms, Reishi shows antioxidant and anti-inflammatory activity. What makes it particularly interesting is that different extracts appear to influence the body in different ways.
Two compound groups appear most relevant to Reishi’s effects: polysaccharides and triterpenoids. Polysaccharides, particularly beta-glucans, are mainly studied for their interactions with the immune system, while triterpenoids are more often linked to antioxidant and anti-inflammatory activity (1,2).
This means Reishi appears to influence both immune function and how the body responds to stress and aging.
Reishi and Immune Health
Reishi appears to act on the immune system through several pathways. In preclinical studies, it has been shown to support the activation and proliferation of T-lymphocytes, natural killer (NK) cells, and dendritic cells, cell types involved in both immediate immune defence and the longer-term adaptive immune response (1).
This is particularly relevant in the context of aging. Immune function declines progressively with age, a process known as immunosenescence, which is associated with increased susceptibility to infection, reduced vaccine response, and elevated chronic inflammation. The compounds in Reishi appear to act on precisely the pathways most affected by this decline.
Beyond immune signalling, Reishi has also been studied for its effects on oxidative stress and cellular maintenance. Its triterpenoid fraction has demonstrated antioxidant and anti-inflammatory activity relevant to how the body manages physiological stress, particularly in relation to mitochondrial function (2).
What Human Research Shows
Human evidence is more developed for Reishi than for many medicinal mushrooms, though limitations remain.
A randomised, double-blind, placebo-controlled trial in healthy adults aged 18 to 55 found that supplementation with Reishi beta-glucan over 84 days increased several T-lymphocyte populations and NK cell counts compared with placebo (3). Researchers are interested in these changes because they may reflect better maintenance of immune health as immune responsiveness naturally declines with age.
A separate 2024 clinical study in older women reported that 2 g daily of Reishi dry extract taken for eight weeks influenced T-lymphocyte activity (4), again suggesting potential relevance for aging immune systems.
Research on cardiovascular and metabolic health is also encouraging, though findings remain mixed. A controlled human intervention trial using 1.44 g daily of Reishi extract over 12 weeks reported favourable changes in several lipid and metabolic markers (5), while a recent systematic review and meta-analysis noted a generally positive direction of effect across multiple cardiometabolic outcomes despite substantial variability between studies (6).
These findings suggest Reishi helps support how the body responds to stress, aging, and immune challenges. They also highlight why formulation matters when choosing a Reishi supplement.
Choosing a Reishi Supplement
Reishi is most commonly taken as an extract rather than whole mushroom.
Human studies have used Reishi extracts at doses ranging from around 1.4 to 5.4 g per day, depending on the extract type and study design. In immune-focused studies, 2 g daily of dry extract over eight weeks and 5.4 g daily of polysaccharide extract over 12 weeks have shown measurable effects on immune markers (4,7). For whole dried mushroom powder, the range used in research is typically 1.5 to 6 g daily (1).
Two factors matter most when choosing a product:
Standardisation: Look for products specifying beta-glucan and triterpenoid content rather than total polysaccharides alone, as these are the compound groups with the most research behind them.
Consistency: Reishi’s effects appear to build gradually with consistent use, making regular use more relevant than precise timing.
Explore Augment Life’s medicinal mushroom range, including Reishi, Lion’s Mane, and Chaga.
Safety Considerations
Reishi is generally well tolerated at doses used in research. Mild digestive discomfort is the most commonly reported side effect. Rare cases of liver enzyme elevation have been reported with very high doses or prolonged use. Those taking anticoagulant medications should exercise caution, as Reishi may have mild antiplatelet effects (1).
Literature Sources
- Wachtel-Galor S, Yuen J, Buswell JA, Benzie IFF. Ganoderma lucidum (Lingzhi or Reishi): A medicinal mushroom. In: Benzie IFF, Wachtel-Galor S, editors. Herbal Medicine: Biomolecular and Clinical Aspects. 2nd ed. CRC Press; 2011.
- Wu YL, Han F, Luan SS, et al. Triterpenoids from Ganoderma lucidum and their potential anti-inflammatory effects. Journal of Agricultural and Food Chemistry. 2019;67(18):5147–5158. DOI: 10.1021/acs.jafc.9b01195
- Chen SN, Nan FM, Liu MW, et al. Evaluation of immune modulation by β-1,3;1,6 D-glucan derived from Ganoderma lucidum in healthy adult volunteers: A randomised controlled trial. Foods. 2023;12(3):659. DOI: 10.3390/foods12030659
- Iser-Bem PN, et al. Ganoderma lucidum dry extract supplementation modulates T lymphocyte function in older women. British Journal of Nutrition. 2024;132(2):130–140. DOI: 10.1017/S0007114524001144
- Chu TT, Benzie IF, Lam CW, et al. Study of potential cardioprotective effects of Ganoderma lucidum (Lingzhi): results of a controlled human intervention trial. British Journal of Nutrition. 2012;107(7):1017–1027. DOI: 10.1017/S0007114511003795
- Jafari A, Mardani H, Mirzaei Fashtali Z, Arghavan B. The Nutritional Significance of Ganoderma lucidum on Human Health: A GRADE-Assessed Systematic Review and Meta-Analysis of Clinical Trials. Food Science & Nutrition. 2025;13(6):e70423. DOI: 10.1002/fsn3.70423
- Gao Y, et al. A phase I/II study of a Ganoderma lucidum extract (Ganopoly) in patients with advanced cancer. International Journal of Medicinal Mushrooms. 2002;4(3):207–214.
