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Reishi powder

Also known as: Reishi, lingzhi, mannentake, Ganoderma lucidum

Overview

Reishi powder is derived from the dried fruiting body, spores, or mycelium of *Ganoderma lucidum*, a medicinal mushroom native to East Asia. Traditionally revered in East Asian medicine for immune support, longevity, and general wellness, modern research explores its potential in lipid modulation, immune modulation, and antioxidant effects. It contains bioactive compounds like triterpenoids (e.g., ganoderic acids) and polysaccharides (e.g., β-glucans). Typically consumed as a powder, extract, or capsule, Reishi has a bitter taste and is not a significant source of macronutrients. While numerous in vitro and animal studies exist, high-quality human clinical trials are limited, and evidence for most claims is often insufficient or conflicting.

Benefits

Animal meta-analyses suggest *Ganoderma lucidum* supplementation may significantly reduce triglycerides, total cholesterol, and LDL-C, while increasing HDL-C, particularly in hyperlipidemic and diabetic models. For instance, one meta-analysis reported a standardized mean difference of −2.27 for LDL-C reduction in male rats. However, human evidence is much weaker; major databases rate Reishi as “possibly ineffective” for hyperlipidemia in people, with no consistent cholesterol-lowering effect observed in clinical trials. Preliminary evidence also points to potential immunomodulatory and antioxidant effects, but these are not well-quantified in humans. The clinical significance of observed animal effects in humans remains uncertain due to a lack of robust randomized controlled trials.

How it works

Reishi's proposed mechanisms of action include the inhibition of cholesterol synthesis, enhancement of bile acid excretion, and modulation of lipid metabolism enzymes. Its triterpenoids may inhibit HMG-CoA reductase, a key enzyme in cholesterol synthesis. Polysaccharides are thought to modulate immune responses by interacting with pathways like Toll-like receptors and NF-κB. Reishi primarily affects the liver, influencing lipid metabolism, and the immune system, by modulating cytokine production and immune cell activity. The absorption and bioavailability of its bioactive compounds, such as triterpenoids and polysaccharides, are poorly characterized in humans and are believed to be low, which may limit its efficacy.

Side effects

Reishi is generally considered safe for short-term use in most adults, but its long-term safety remains uncertain. Common side effects, reported in some human studies, include gastrointestinal discomfort such as dry mouth, nausea, and diarrhea. Less common side effects (1–5% frequency) may include rash, dizziness, and headache. Rare but serious side effects, such as liver toxicity, have been reported in case studies. There is a theoretical risk of bleeding due to potential antiplatelet effects. Reishi may interact with certain medications, including anticoagulants, antihypertensives, and immunosuppressants, based on in vitro and animal data. It is contraindicated during pregnancy and lactation due to a lack of safety data, and caution is advised for individuals with bleeding disorders or those scheduled for surgery. It is not recommended for children, and elderly or immunocompromised individuals should use it with caution.

Dosage

The minimum effective dose of Reishi in humans has not been established. Typical human doses range from 1.5 to 9 grams per day of dried powder or an equivalent extract, but these dosages are not evidence-based. The maximum safe dose is also not established, and long-term use (beyond one month) is generally not recommended due to uncertain safety. Reishi is usually taken with meals to help reduce potential gastrointestinal side effects. While standardized extracts may offer more consistent dosing of active compounds like triterpenes or polysaccharides, their clinical superiority over whole powder is unproven. Bioavailability is likely low, and taking Reishi with fats might enhance the absorption of triterpenoids. No specific cofactors are identified as necessary for its efficacy.

FAQs

Is Reishi safe for long-term use?

Short-term use appears safe for most, but long-term or high-dose use is not recommended due to uncertain safety and potential side effects. Consult a healthcare professional for guidance.

When is the best time to take Reishi?

It is generally recommended to take Reishi with meals to minimize potential gastrointestinal upset. Any effects, if experienced, may take several weeks to manifest.

What health benefits can I expect from Reishi?

While animal studies show promise for lipid modulation, robust human clinical evidence for most health claims is lacking. Most users may not experience measurable or consistent health benefits.

Can Reishi interact with medications?

Yes, Reishi may theoretically interact with anticoagulants, antihypertensives, and immunosuppressants. Always consult your doctor before taking Reishi, especially if you are on medication.

Research Sources

https://www.cureus.com/articles/143256-pharmacological-activities-and-safety-of-ganoderma-lucidum-spores-a-systematic-review.pdf – This systematic review evaluated the pharmacological activities and safety of *Ganoderma lucidum* spores and compounds. It concluded that while preclinical studies report some biological activities, clinical evidence is limited and often of low quality. The review also highlighted that safety data are insufficient for long-term use of Reishi.
https://journals.lww.com/jrms/fulltext/2023/09290/effect_of_ganoderma_lucidum_on_serum_lipid.70.aspx – This systematic review and meta-analysis analyzed 49 animal studies on *G. lucidum*'s effect on lipid profiles. It found significant reductions in triglycerides, total cholesterol, and LDL-C, and increases in HDL-C, particularly in hyperlipidemic and diabetic animal models. While effect sizes were moderate to large, the study noted high heterogeneity and unclear applicability to humans.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10729684/ – This source, likely related to the Aref et al. (2023) meta-analysis, provides further details on the animal study findings regarding *Ganoderma lucidum*'s impact on serum lipid profiles. It reinforces the observation of positive effects on cholesterol and triglyceride levels in animal models, while implicitly or explicitly acknowledging the limitations for human extrapolation.
https://medlineplus.gov/druginfo/natural/905.html – MedlinePlus, via the Natural Medicines Database, rates Reishi as “possibly ineffective” for hyperlipidemia in humans due to a lack of consistent benefit in clinical trials. It also advises that consumption beyond one month may be unsafe and states there is insufficient good evidence to support most of Reishi's purported health claims.