Health Benefits of Reishi

Reishi (Ganoderma lucidum) is a type of medicinal mushroom that has been used in traditional Asian medicine for over two millennia. Commonly known as "Lingzhi" in China and "Reishi" in Japan, this fungus is revered for its potential therapeutic effects, including immune support, anti-inflammatory activity, and antioxidant properties.

Reishi contains bioactive compounds such as polysaccharides, triterpenoids, peptidoglycans, and sterols. These substances are believed to contribute to the mushroom’s purported health benefits. While reishi has been used historically for conditions like fatigue, liver disease, and cancer, scientific evidence is still evolving.

May Have Anticancer Effects

One of the most studied uses of reishi is in cancer support. Traditional Chinese Medicine (TCM) has long included reishi in treatments for cancer and immune health. Some studies suggest that compounds in reishi, particularly polysaccharides like G. lucidum polysaccharides (GLP), might suppress tumor growth and enhance immune function.

In a study involving colorectal cancer patients, those who took 1.5 grams of reishi extract daily for a year experienced reduced growth in precancerous colon lesions. Other small-scale trials have also noted improved immune markers in breast and lung cancer patients.

These effects may be due to reishi’s stimulation of natural killer (NK) cells and other immune responses. However, most of the current data is based on animal studies or limited human trials, and the reishi extracts used often differ from commercial supplements available in the U.S.

Supports Urinary Tract Health in Men

Reishi may be beneficial for men with lower urinary tract symptoms (LUTS), particularly those related to benign prostatic hyperplasia (BPH), a non-cancerous enlargement of the prostate gland.

In two separate clinical trials, men taking doses ranging from 6 mg to 60 mg of reishi extract for 8 to 12 weeks reported improvements in urinary symptoms such as weak urine stream and incomplete bladder emptying.

These effects are likely due to reishi’s anti-inflammatory properties, which can help reduce inflammation in the prostate region. Still, more research is necessary to validate these findings.

May Help Lower Risk Factors for Heart Disease

Reishi has been marketed for its potential to reduce cardiovascular risk factors, including high cholesterol, triglycerides, and blood sugar.

Older studies showed some promise, but recent clinical trials have had mixed results. For example, one 16-week study involving individuals with type 2 diabetes found no significant improvement in fasting blood sugar or HbA1c levels with 3 grams of reishi extract daily.

Animal studies do indicate that reishi might have cardioprotective properties, possibly through its antioxidant and anti-inflammatory actions, but human research is still inconclusive.

How To Take Reishi

Reishi mushrooms grow naturally on hardwood trees in regions across Asia, North America, South America, and Europe. In supplement form, reishi is available as capsules, powders, liquid extracts, teas, and even added to functional foods like protein bars and coffee creamers.

When choosing a supplement, always check the label for dosage and additional ingredients. Reishi-only products are available, but many blends include other mushrooms or herbs.

Recommended Dosage

Doses vary depending on the form:

  • Whole mushroom: 1,400–5,400 mg daily

  • Extracts: 3–6 mg daily

Supplements are often taken in divided doses. As with any supplement, it's best to consult with a healthcare provider to determine the right dosage for your needs.

Due to inconsistencies in labeling and potency, look for products that have undergone third-party testing by organizations like NSF International, USP, or ConsumerLab.

Safety and Potential Side Effects

Reishi is considered safe when used in recommended amounts for up to 12 months. Reported side effects are usually mild and may include:

  • Nausea

  • Dizziness

  • Insomnia

  • Fatigue

  • Dry mouth or sore throat

  • Rash or skin irritation

In rare cases, prolonged use or high doses have been associated with liver toxicity and liver failure. Some evidence suggests high-dose reishi may elevate tumor marker CA72-4, especially in people with cancer. Always speak with a healthcare provider before using reishi, particularly if you have liver disease or are undergoing cancer treatment.

Drug Interactions

Reishi can interact with certain medications:

  • Blood thinners: May increase bleeding risk when taken with anticoagulants like warfarin.

  • Immunosuppressants: Could interfere with medications that suppress the immune system.

  • Chemotherapy: Might interfere with cancer drugs.

  • Anti-diabetic and anti-hypertensive drugs: Reishi may amplify their effects.

Consult your healthcare provider before starting reishi if you're taking prescription medications.

Can You Take Too Much?

There’s no established upper limit for reishi intake. However, because large doses have been linked to liver issues, it's important to follow dosage guidelines.

Stick with manufacturer-recommended doses and consult a healthcare provider if you plan to use reishi long-term.

A Quick Review

Reishi is a traditional medicinal mushroom that shows potential in supporting immunity, reducing inflammation, and possibly helping with cancer treatment, urinary symptoms, and cardiovascular health. However, more research is needed to confirm its benefits.

If you're considering adding reishi to your wellness routine, consult your healthcare provider—especially if you’re managing chronic health conditions or taking other medications.