CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-19). The draft was written by AI, the existence of all 4 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 729 · Search date 2026-07-19 · Methodology v0.6

Agaricus blazei extract,
does it really help with Cancer prevention, reduced recurrence, and prolonged survival?

30-Second Summary
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Evidence Grade ? · Safety unknown
Immune-marker studies cannot be converted into evidence of cancer prevention, reduced recurrence, or longer survival
What the
research shows
Agaricus blazei extract is rated ? for preventing cancer, reducing recurrence, or prolonging survival. Human research has focused on phase I safety, quality of life, and surrogate markers such as immune-cell subsets and cytokines. A roughly seven-week randomized trial in 40 people with multiple myeloma found immune changes with the mixed mushroom extract AndoSan, but treatment response, overall survival, and time to new treatment were not significantly different. A 2026 trial in 66 people after lung-cancer surgery tested a multivitamin complex containing Agaricus, focused on 28-day immune recovery, and found no significant three-year recurrence-free-survival difference; an Agaricus-only effect cannot be assigned. No adequate standalone prevention, recurrence, or survival trial exists, so no score is assigned.
What the
ads claim
Marketing converts tumor-cell inhibition in vitro or changes in natural-killer cells and cytokines into cancer prevention, blocked recurrence, and longer survival. Immune surrogates are not patient-important cancer outcomes, and results from mixtures cannot be assigned to one ingredient.
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Useful facts when choosing a product

  • Agaricus blazei is also classified as Agaricus subrufescens and is sold under names including Agaricus, himematsutake, and royal sun mushroom.
  • Extraction method, beta-glucan content, mycelium-to-fruiting-body ratio, and inclusion of other mushrooms vary, so results from products such as AndoSan cannot be applied to generic powders.
  • Agaricus supplements must not replace surgery, chemotherapy, immunotherapy, or other cancer treatment, and use during treatment should be disclosed to the oncology team because of possible liver effects and interactions.
  • Severe liver injury and worsening after rechallenge have been reported, and contamination or compositional variation is possible; jaundice, dark urine, or severe fatigue warrants discontinuation and medical evaluation.
Gap Measurement · Verdict 729 · ?
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Ohno 2011 followed 78 cancer patients in remission taking an Agaricus product for six months in a phase I study of safety, allergy, and quality of life; it was not a controlled recurrence or survival efficacy trial. Tangen 2015 randomized 40 people with multiple myeloma to AndoSan or placebo and found immune-marker changes but no significant treatment-response, overall-survival, or time-to-new-treatment difference. Kim 2026 randomized 66 people after non-small-cell lung-cancer resection to a multivitamin and mineral complex containing Agaricus or placebo for 28 days; immune surrogates were central and three-year recurrence-free survival did not differ significantly. None tested whether an ordinary standalone Agaricus supplement prevents cancer incidence.

02

Why this is classified as ?

Human studies focus on immune surrogates, quality of life, phase I safety, or multi-ingredient products, with no adequate trial of standalone Agaricus on cancer incidence, recurrence, or survival. The grade is ? and the score is null. Hepatotoxicity reports and quality variation remain separate safety concerns.

Counterpoint. Outside research, there is no evidence-based reason to choose this supplement to prevent cancer or recurrence. Validated screening, smoking cessation, weight management, vaccination, and cancer-specific standard treatment and surveillance take priority.

Rejudgment record. New verdict — Human Agaricus studies concentrate on phase I safety, quality of life, immune surrogates, or mixed mushroom and multivitamin products; because no adequate randomized trial directly tests standalone Agaricus for cancer incidence, recurrence, or survival, the no-direct-efficacy-literature verdict applies

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Prevention of cancer incidence?No adequate standalone human Agaricus trial directly evaluated cancer incidence.
Reduced cancer recurrence?Exploratory recurrence-free survival with a multi-ingredient product was nonsignificant and cannot be attributed to one ingredient.
Prolonged cancer survival?Overall survival was nonsignificant in a small mixed-extract trial, with no adequate confirmatory study.
Changes in immune cells or cytokinesCSome small trials found surrogate changes, but these are not equivalent to cancer outcomes.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Ohno S et al. 2011Six-month open-label phase I safety study78Public cancer-research support from the Japanese Ministry of Health, Labour and WelfareAdverse events, laboratory safety, allergy, and quality of lifeThe product was generally tolerated with some allergic reactions, but cancer recurrence and survival efficacy were not tested.Safety evidence without direct efficacy
Tangen JM et al. 2015Double-blind randomized placebo-controlled adjunctive trial40Norwegian public and research support; AndoSan mixed extractImmune markers, treatment response, overall survival, and time to new treatmentSome immune markers changed, but treatment response, overall survival, and time to new treatment did not differ significantly.Small mixed-product trial with nonsignificant clinical outcomes
Kim J et al. 2026Multicenter double-blind randomized placebo-controlled pilot66Commercial multivitamin complex with limited ingredient attributionTwenty-eight-day immune cells, cytokines, quality of life, and exploratory three-year recurrence-free survivalMajor immune and patient-reported outcomes did not differ, and three-year recurrence-free survival was also nonsignificant.Recent but multi-ingredient and surrogate-focused
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Receipt — 4 References

All 4 cited sources were verified for existence at the original page (as of 2026-07-19).

Ohno S, Sumiyoshi Y, Hashine K, Shirato A, Kyo S, Inoue M. Phase I Clinical Study of the Dietary Supplement, Agaricus blazei Murill, in Cancer Patients in Remission. Evid Based Complement Alternat Med. 2011;2011:192381. PMID: 21584278. PMCID: PMC3092499. DOI: 10.1155/2011/192381.
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Tangen JM, Tierens A, Caers J, et al. Immunomodulatory effects of the Agaricus blazei Murrill-based mushroom extract AndoSan in patients with multiple myeloma undergoing high dose chemotherapy and autologous stem cell transplantation: a randomized, double blinded clinical study. Biomed Res Int. 2015;2015:718539. PMID: 25664323. PMCID: PMC4312620. DOI: 10.1155/2015/718539.
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Kim J, Ji W, Kim HR, Lee GD, Lee SH. Immunomodulatory Effects of Multivitamin Complexes Containing Agaricus blazei in Patients Undergoing Curative Resection for Non-Small-Cell Lung Cancer: A Randomized, Double-Blind, Placebo-Controlled Multicenter Pilot Trial. Biomedicines. 2026;14(1):53. PMID: 41595590. PMCID: PMC12839190. DOI: 10.3390/biomedicines14010053.
checked
Mukai H, Watanabe T, Ando M, Katsumata N. An alternative medicine, Agaricus blazei, may have induced severe hepatic dysfunction in cancer patients. Jpn J Clin Oncol. 2006;36(12):808-810. PMID: 17105737. DOI: 10.1093/jjco/hyl108.
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Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-19 · Corrections: none

Cite this verdict

Agaricus blazei extract x cancer prevention, reduced recurrence, and prolonged survival Evidence Grade ? card
[Chamgap] Agaricus blazei extract x cancer prevention, reduced recurrence, and prolonged survival — Evidence Grade ?. 4 cited sources checked. Source: https://chamgap.com/en/verdicts/immunity/agaricus-blazei-cancer-prevention-recurrence-survival/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.