What is it?
Reishi mushroom is a fungus. Some people describe it as “tough” and “woody” with a bitter taste. The above-ground part and portions of the below-ground parts are used as medicine.
Reishi mushroom is used for cancer, boosting the immune system to prevent or treat infections, and for many other conditions, but there is no good scientific evidence to support these uses.
Possibly Ineffective for …
- High levels of cholesterol or other fats (lipids) in the blood (hyperlipidemia). Reishi mushroom does not seem to lower cholesterol in people with diabetes, high blood pressure, or high cholesterol.
Insufficient Evidence to Make a Determination for …
- Alzheimer disease. Early research shows that taking reishi mushroom powder does not improve memory or quality of life in people with Alzheimer disease.
- Enlarged prostate (benign prostatic hyperplasia or BPH). Men with enlarged prostates often have urinary symptoms. Taking reishi mushroom extract can improve some urinary symptoms such as the need to urinate often or immediately. But other symptoms such as urine flow rate don’t seem to improve.
- Tiredness in people with cancer. Early research shows that taking reishi mushroom powder reduces tiredness in people with breast cancer.
- Noncancerous growth in the large intestine and rectum (colorectal adenoma). Early research shows that taking reishi mushroom extract can reduce the number and size of these tumors.
- Heart disease. Early research shows that taking reishi mushroom extract (Ganopoly) reduces chest pain and shortness of breath in people with heart disease.
- Diabetes. Most research shows that taking reishi mushroom extract doesn’t improve blood sugar control in people with diabetes. But most of these studies were small, and some conflicting results exist.
- Genital herpes. Early research shows that taking a mixture of reishi mushroom and other ingredients reduces the time needed for herpes outbreaks to heal.
- Swelling (inflammation) of the liver caused by the hepatitis B virus (hepatitis B). Early research shows that taking reishi mushroom (Ganopoly) reduces how much of the hepatitis B virus is in the body. This product also seems to improve liver function in people with this condition.
- Cold sores (herpes labialis). Early research shows that taking a mixture of reishi mushroom and other ingredients reduces the time needed for cold sores to heal.
- High blood pressure. Taking reishi mushroom doesn’t seem to lower blood pressure in people with only slightly high blood pressure. But it seems to lower blood pressure in people with more severe high blood pressure.
- Lung cancer. Early research shows that taking reishi mushroom does not shrink lung tumors. But it might improve immune function and quality of life in people with lung cancer.
- A sexually transmitted infection that can lead to genital warts or cancer (human papilloma virus or HPV).
- Altitude sickness.
- Swelling (inflammation) of the main airways in the lungs (bronchitis).
- Chronic fatigue syndrome (CFS).
- Long-term kidney disease (chronic kidney disease or CKD).
- Heart disease.
- Nerve pain caused by shingles (postherpetic neuralgia).
- Shingles (herpes zoster).
- Stomach ulcers.
- Other conditions.
More evidence is needed to rate the effectiveness of reishi mushroom for these uses.
Special Precautions & Warnings:
Pregnancy and breast-feeding: There isn’t enough reliable information to know if reishi mushroom is safe to use when pregnant or breast feeding. Stay on the safe side and avoid use.
Bleeding disorders: High doses of reishi mushroom might increase the risk of bleeding in some people with certain bleeding disorders.
Low blood pressure: Reishi mushroom might lower blood pressure. There is a concern that it might make low blood pressure worse. If your blood pressure is too low, it is best to avoid reishi mushroom.
Surgery: High doses of reishi mushroom might increase the risk of bleeding in some people if used before or during surgery. Stop using reishi mushroom at least 2 weeks before a scheduled surgery.
Medications for high blood pressure (Antihypertensive drugs)
Interaction Rating=Moderate Be cautious with this combination.
Reishi mushroom might decrease blood pressure. Taking reishi mushroom along with medications for high blood pressure might cause your blood pressure to go too low.
Some medications for high blood pressure include captopril (Capoten), enalapril (Vasotec), losartan (Cozaar), valsartan (Diovan), diltiazem (Cardizem), Amlodipine (Norvasc), hydrochlorothiazide (HydroDIURIL), furosemide (Lasix), and many others.
Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)
Interaction Rating=Moderate Be cautious with this combination.
High doses of reishi mushroom might slow blood clotting. Taking reishi mushroom along with medications that also slow clotting might increase the chances of bruising and bleeding.
Some medications that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), naproxen (Anaprox, Naprosyn, others), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, warfarin (Coumadin), and others.
Herbs and supplements that might lower blood sugar: Reishi mushroom might lower blood sugar. Using it along with other herbs and supplements that have the same effect might cause blood sugar to drop too low in some people. Some of these products include alpha-lipoic acid, bitter melon, chromium, devil’s claw, fenugreek, garlic, guar gum, horse chestnut seed, Panax ginseng, psyllium, Siberian ginseng, and others.
Herbs and supplements that might slow blood clotting: The effect of reishi mushroom on blood clotting is not clear. Higher amounts (about 3 grams per day) but not lower doses (1.5 grams per day) might slow blood clotting. There is a concern that taking reishi mushroom along with other herbs that slow blood clotting could increase the risk of bruising and bleeding. Some of these herbs include angelica, anise, arnica, clove, danshen, garlic, ginger, ginkgo, Panax ginseng, horse chestnut, red clover, turmeric, and others.
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