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Agarikon (Fomitopsis officinalis)
Rare old-growth mushroom with compounds that were antiviral in laboratory studies, one of the oldest medicinal fungi known to science. Human immune benefit is not established.
What the evidence says
Most Agarikon studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from mixed-quality randomised trials published 2011–2026.
Based on 11 studies · 1 RCT
Confidence
Low confidenceBy outcome
Lab and animal studies show broad antiviral, immunomodulatory, and antitumor activity, but there are no human clinical trials, so benefits remain entirely preclinical.
Agarikon is one of the oldest mushrooms used medicinally, with references dating back to ancient Greek physician Dioscorides who called it the 'elixir of long life.' It grows on old-growth conifer trees and is now quite rare.
Laboratory studies have revealed antiviral compounds, but human clinical evidence is very limited — most research remains preclinical (in-vitro and animal studies).
Contains multiple antiviral molecules
Polysaccharides activated immune cells in laboratory and animal studies
How Agarikon works — from molecular targets to health outcomes. Click an edge to see supporting research.This visualization is in beta — pathways are being refined and expanded.
Limited human safety data; use with appropriate caution
Medicinal mushrooms may affect blood clotting; use caution A grade for this interaction is held for clinical review and has not been validated, so no severity is given. The precaution still applies: ask a pharmacist about the exact supplement and medicine. Do not stop or change prescribed medicines based on this notice.
May counteract immunosuppressive effects due to immune-stimulating properties
May affect blood sugar levels; monitor glucose A grade for this interaction is held for clinical review and has not been validated, so no severity is given. The precaution still applies: ask a pharmacist about the exact supplement and medicine. Do not stop or change prescribed medicines based on this notice.
Tip: Take with food
Agarikon has an evidence score of 3.5/10 — emerging evidence based on 11 indexed studies. Rare old-growth mushroom with compounds that were antiviral in laboratory studies, one of the oldest medicinal fungi known to science. Human immune benefit is not established. Representative study: PMID 32271491.
Dosing for Agarikon: No dose is endorsed. No cited trial of agarikon alone states a dose, and the supplied evidence does not establish a safe dose for self-administration.
Timing is flexible for Agarikon — consistent daily use matters more than the time of day. Fomitopsis officinalis (agarikon) polysaccharides and triterpenoids do not have strong time-of-day dependencies.
No consumer dose of Agarikon is endorsed, so there is no dose at which it can be called safe. Talk to a healthcare provider before taking it. Reported side effects are uncommon and include GI upset. Use caution if any of these apply to you: Known allergy or hypersensitivity to Agarikon or related compounds.
Shiitake
Too few graded studiesA culinary mushroom containing lentinan and eritadenine. Human evidence is limited to small RCTs — preliminary immune signals and a modest triglyceride effect, with no large trials or meta-analyses.
Turkey Tail
Mostly mechanism / observationalMedicinal mushroom whose extracts PSK and PSP are used alongside cancer treatment in Japan and China. Meta-analyses found a modest survival benefit in cancer patients, with little human data outside cancer care.
Reishi
Mostly mechanism / observationalA traditional calming mushroom rich in beta-glucans and triterpenes. The honest verdict: most evidence is preclinical or review-level; human RCTs are few, small, and mixed, and Cochrane found insufficient evidence for cancer or cardiovascular use.
Tremella
Mostly mechanism / observationalA culinary mushroom whose polysaccharides hold a lot of water in the lab. The honest verdict: the popular skin-hydration claims rest on mechanism, not human trials — there are no skin-outcome RCTs, only a couple of small cognition studies.
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Reviewed by Dr. Baher Al Hakim · Last reviewed May 2026 · evidence from 11 studies · how we score · editorial policy
This information is for educational purposes only. It is not a substitute for professional medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement or medication.
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