herb · for frequent colds
Reishi
Its beta-glucans wake up the immune cells that hunt down infections.
Say that in clinical terms
Beta-glucan polysaccharides potentiate immune function and enhance NK cell activity against pathogens.
How strong is the research?
Solid evidence
A different form was studiedIndustry funded
3 papers read, 2 supporting.
Tested as: Ganoderma lucidum-derived beta-1,3;1,6 D-glucan supplement
Who was studied: The immune research is mostly in cancer patients, the elderly and the immunocompromised.
How much to take
daily
1000–1500 mg
Prophylactic immune support. Beta-glucan content varies by extraction method.
Before you take it
- Platelet inhibition via triterpenes — clinically significant interaction with anticoagulants (warfarin), antiplatelet agents (aspirin, clopidogrel), thrombolytics, and NSAIDs; documented in human and animal studies since 1984 (PMID 4085058, PMID 2098581)
- CYP2E1 inhibition confirmed; potential effects on CYP3A4 and CYP1A2 — review all concomitant hepatically metabolized medications before co-administration
- Rare but documented hepatotoxicity with concentrated powdered extracts, including a fatal fulminant hepatitis case (PMID 17621752, 2007) and an additional case report in Journal of Hepatology (PMID 15464254, 2004); liver function monitoring is warranted with long-term or high-dose use
- No NIH Tolerable Upper Intake Level established for Reishi mushroom; controlled human safety data beyond 12 weeks is limited
- Insufficient evidence for safety in pregnancy or lactation — use should be avoided in these populations
What we make of it
A 2001 paper that is almost certainly a review, not the pooled analysis we labelled it.
The detail
The paper we cite is from 2001 on polysaccharides and immune activity, which reads as a review or laboratory work rather than the statistical pooling our label implies.