Reishi Mushrooms

Reishi is one of the mushrooms our naturopaths get asked about most. These are the questions they ask in store before you take it home.

A good fit if

• Immune support is your reason for buying, and you want a single species
• You're comfortable with evidence that measures blood markers rather than sick days
• You want the Latin name and a beta-glucan figure on the label
• You'd like the triterpenes too, so you're choosing a dual extract

Check with us first if

• You're having, or have had, cancer treatment. Cochrane found no evidence to support reishi as a first-line cancer treatment, and a review of case reports in people with cancer found mushroom products were the ones most often involved in severe reactions. Talk to your treating team first.
• You take a medicine that affects your immune system, including after a transplant. We haven't found a human interaction study for reishi, so we won't guess either way.
• You take warfarin or another blood thinner. Australia's required warfarin warning applies to maitake, not reishi, and we won't stretch it. Bring the pack in anyway.
• You're pregnant or breastfeeding. No trial of these mushrooms included pregnant or breastfeeding women, and Australia's permitted ingredients list sets no warning either way. That isn't the same as evidence that it's safe.
• It's for a child. There's no safety guidance for reishi in children.

• Hot-water extract. Best known for: The water-soluble beta-glucan fraction. Absorption: Ratios such as 8:1 concentrate the fibre; the class used in immune-marker trials. Typical use: The usual pick when immune support is the reason.
• Dual extract (water plus alcohol). Best known for: Beta-glucans plus the bitter triterpenes particular to reishi. Absorption: The alcohol step adds the fraction hot water leaves behind. Typical use: When you want both fractions in one product.
• Whole dried powder. Best known for: The ground fruiting body, not concentrated. Absorption: No concentration step, so you get whatever the mushroom held. Typical use: Cheapest per gram; ask for a beta-glucan figure first.
• Spore oil. Best known for: The lipid fraction of cracked spores, a different product altogether. Absorption: One trial, and it didn't state its dose. Typical use: Not interchangeable with a reishi powder or extract.

Reference values. There's no Nutrient Reference Value for reishi. It's a fungus, not an essential nutrient, so the NHMRC doesn't set one.

Typical supplemental range. Most reishi trials we've reviewed used 1 to 3 g a day. The Cochrane review pooled trials at 1.4 to 3 g a day for 12 to 16 weeks, and the trial in older women used 2,000 mg a day of dry extract for 8 weeks. Australian products often give around 1 to 2 g a day of extract. These figures are for context, not a recommendation, and extracts vary a lot in strength, so read the label and follow its directions.

Upper level. None is set. Australia's permitted ingredients list (Schedule 1) has no daily dose cap for Ganoderma lucidum. That doesn't mean there's no limit, only that the rules don't set one, and one small trial found symptoms got worse at a higher dose in a specific group of men.

Worth knowing. If you're comparing two tubs, compare the beta-glucan percentage rather than the milligrams. A bigger amount of a weaker extract doesn't give you more. What you need depends on your age, diet and health, so talk to one of our naturopaths.

Food first, where the diet allows it.

• Reishi itself: not eaten as food; taken as a powder or extract
• Shiitake, oyster and enoki: culinary sources of the same (1,3)(1,6)-beta-D-glucan fibre

This list is the part of the page we will not shorten. If any of it applies to you, talk to one of our naturopaths or your doctor before starting.

• Known mushroom or mould allergy. Allergy was the predominant mechanism in the severe cases reviewed across 92 case reports in cancer patients, and mushroom products were mostly the products used.
• Cancer patients. Cochrane didn't find sufficient evidence to justify Ganoderma lucidum as a first-line cancer treatment, and study quality was generally unsatisfying. Refer to the treating team.
• Higher doses in some people. In 29 men with Gulf War Illness, symptom severity was higher than placebo at the higher reishi dose (p=0.012).
• Adverse events overall. In Cochrane's pooled trials, reishi takers were 1.67 times as likely to report an adverse event as placebo (95% CI 0.86 to 3.24), none serious.
• Pregnancy and breastfeeding. No cached trial in this family enrolled pregnant or breastfeeding women, and Schedule 1 imposes no pregnancy warning on Ganoderma lucidum.
• Children. No paediatric safety position is established for reishi.
• Immunosuppressants, transplant medicine and anticoagulants. No human interaction study is held, so nothing is asserted in either direction.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths before starting.