Know2eat

Agaricus blazei

Agaricus subrufescens

Medicinal Mushrooms

What agaricus blazei may help with

Ranked by how strong the human evidence is — best supported first.

Best supportedImmune functionNot enough evidence· 4 sources

Then, in order

About Agaricus blazei

A cultivated mushroom of Brazilian origin that became popular in Japan as a cancer supplement, sold as dried powder, hot-water extract or fermented preparations. Its taxonomy has been repeatedly revised.

Agaricus blazei is a case where the safety signal is clearer than the efficacy signal. It was heavily promoted in Japan for cancer support in the 1990s and 2000s; then Japanese researchers reported severe liver injury in cancer patients taking one particular Agaricus blazei extract product, and the Japanese health ministry issued warnings. Efficacy trials are small, mostly conducted in Japan, Korea and Brazil, and report immune parameter changes and some quality-of-life differences during chemotherapy without establishing a clinical benefit. The mushroom is also a documented accumulator of cadmium and other heavy metals from the growing substrate.

Sold as
Dried powder, Hot-water extract, Fermented extract, Capsule
Standardised to
Occasionally beta-glucan percentage; the product implicated in liver injury was a specific commercial extract — a product without this marker may not resemble what was studied.
Also known as
Agaricus blazei Murill, ABM, Himematsutake, Cogumelo do sol, Almond mushroom

Regulation: Sold as a dietary supplement in the US with no pre-market efficacy review. Japanese authorities issued warnings about hepatotoxicity associated with a commercial Agaricus blazei extract, and one product was withdrawn from sale.

What the research used

The amounts, forms and durations published trials of Agaricus blazei actually administered.

These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.

  • Studied for Chemotherapy supportive-care trials

    1800–5400 mg

    Not enough

    Extract or powder, daily · 3 weeks to 6 months

    Doses in small Korean and Japanese studies alongside chemotherapy. Sample sizes are in the tens and outcomes are immune markers or symptom scores.

This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.

When it was taken

Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.

None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.

  • Any time

    Not enough

    No timing research exists for this mushroom.

    Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.

The evidence in depth

Best supported: Not enough

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.

Immune function

Immune Health
Not enough evidence

Small trials during chemotherapy report changes in natural killer cell activity and symptom scores. They are underpowered, inconsistently controlled and cannot support an immune claim.

Not enough evidence. Not enough human research to say anything useful yet.

View the 4 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Insulin sensitivity

Blood Sugar & Metabolic Health
Not enough evidence

One small trial in people with type 2 diabetes reported improved insulin resistance measures. It is a single study and has not been replicated.

Not enough evidence. Not enough human research to say anything useful yet.

View the 1 source

Deep research mode adds each paper’s own conclusion and stated limitations.

Things to know

Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.

  • Worth knowing

    Severe liver injury reported in cancer patients

    Japanese reports described serious hepatic dysfunction in cancer patients taking a commercial Agaricus blazei extract, prompting an official warning and a product withdrawal. Anyone with liver disease should avoid it, and it should not be added during cancer treatment without oncology input.

  • Worth knowing

    Heavy metal accumulation

    Agaricus species accumulate cadmium and other metals from their growing substrate, and elevated levels have been measured in commercial products. Without a heavy metal certificate of analysis this is an unquantified exposure taken daily.

  • Interaction

    Immunosuppressants and cancer therapy

    Interacts withImmunosuppressants, chemotherapy

    Immunomodulating activity makes it unsuitable alongside transplant immunosuppression, and the liver injury reports concentrate in exactly the cancer population that is most often marketed to.

  • Too much

    Digestive upset and allergic reactions

    Nausea, diarrhoea and skin reactions have been reported. As with all fungal products, allergic reactions occur in sensitised people.

Evidence ratings on this page: 2 not enough evidence.

Supplements are sold in the US without pre-market review of efficacy or safety. Nothing on this page is a recommendation to take Agaricus blazei, or a dose to follow.