NutriDex

The Supplement Research Compendium
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Maitake

Grifola frondosa

Culinary mushroom studied for immune and blood-sugar support.

Preliminary evidence 🛡️Gut & Immune

✚ Updated · How we grade evidence

Evidence tier
Preliminary
Research weight
Citations
8 verified / 8
Classification
Gut & Immune
❝
What the evidence says. Graded preliminary: human data are limited to small, mostly open-label or single-arm trials (breast cancer, MDS, PCOS) plus diabetes case reports. Immune effects were statistically real but non-monotonic, and no large RCT confirms a clinically meaningful benefit. (Preliminary evidence: Early or small human trials; promising but not yet conclusive.)

What is Maitake?

Maitake (Grifola frondosa) is a gut and immune supplement used for immune cell activation. NutriDex grades the human evidence as Preliminary. Maitake is an edible mushroom whose beta-glucan extracts (D/MD-fraction) and an SX-fraction glycoprotein are sold for immune and metabolic support. The strongest human work is a Memorial Sloan Kettering phase I/II trial in 34 breast-cancer survivors, where oral extract significantly altered immune parameters (p<0.0005) but unpredictably — intermediate doses sometimes enhanced and sometimes suppressed function. A phase II trial in 18 myelodysplastic-syndrome patients raised basal neutrophil (p=0.005) and monocyte (p=0.021) activity. An open PCOS trial reported ovulation in ~77% on maitake extract, and small diabetes pilots and case reports describe fasting-glucose drops. A 2009 systematic review concluded human evidence remains too sparse and uncontrolled to confirm efficacy, calling for randomized trials. So maitake is promising mechanistically and well tolerated, but not yet proven to improve any clinical outcome.

Purported Benefits

✓Immune cell activation
✓May lower blood sugar
✓May support insulin sensitivity
✓Adjunct interest in cancer care

Evidence by outcome

The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.

OutcomeEvidenceEffectStudies
Modulation of immune cell activityTwo small phase I/II trials altered immune markers, but breast-cancer dose-response was non-monotonic (sometimes suppressed). Preliminary ↔ mixed 2
Lower blood glucose / insulin sensitivityOnly pilots and a striking single case report; no controlled diabetes RCT confirms a glycemic effect. Preliminary ↑ benefit 2
Induce ovulation in PCOSOne open (non-blinded) trial reported ~77% ovulation; uncontrolled and unreplicated. Preliminary ↑ benefit 1
Improve clinical cancer outcomesA systematic review found no rigorous trials showing maitake improves any cancer outcome. No Evidence — no effect 1

Dosing & Compounds

Typical Dose
No established dose; trials used standardized liquid extract ~1–5 mg/kg twice daily, or culinary powder 3–7 g/day; quality and fraction content vary widely.
Active Compounds
Beta-glucans (D-fraction / MD-fraction)SX-fraction glycoproteinErgosterol

Safety & Cautions

Maitake is generally well tolerated as food and in short trials, with occasional GI upset; people allergic to mushrooms should avoid it. A case report links maitake to a raised INR in a patient on warfarin, so it may potentiate anticoagulants. Because extracts can lower blood glucose, combining with insulin or other antidiabetic drugs risks hypoglycemia and warrants monitoring. Safety in pregnancy, breastfeeding and long-term use is unstudied. Educational only — always check with your doctor or pharmacist before combining Maitake with any medicine.

Maitake drug interactions

Known or theoretical interactions between Maitake and common medications — educational, not exhaustive. Always check with your doctor or pharmacist before combining Maitake with any medicine.

Caution
Diabetes drugs (insulin, metformin)
Maitake can lower blood sugar and may increase the effect of diabetes medications, risking hypoglycemia.
Maitake beta-glucans may improve insulin sensitivity and glucose uptake, adding to the effect of antidiabetic drugs. MSKCC — Maitake

Key Studies

Systematic review Ulbricht 2009 ✓ PubMed
Systematic review: cancer, diabetes and immunity proposed, but no rigorous human studies; concludes randomized controlled trials are warranted.
RCT Wesa 2015 ✓ PubMed
Phase II, 18 MDS patients on 3 mg/kg twice daily x12 wk: increased basal neutrophil (p=0.005) and monocyte (p=0.021) function; well tolerated.
RCT Chen 2010 ✓ PubMed
Open trial in PCOS: maitake SX-fraction extract induced ovulation in 76.9% of patients vs clomiphene; some non-responders ovulated on combination.
RCT Deng 2009 ✓ PubMed
Phase I/II trial, 34 breast-cancer survivors: oral maitake extract significantly changed immune function (p<0.0005), but dose-response was non-monotonic.
Safety Hanselin 2010 ✓ PubMed
Case report: maitake extract added to warfarin elevated INR; mechanism proposed via beta-glucan displacing protein-bound warfarin.
Review Konno 2020 ✓ PubMed
Narrative review of SX-fraction: water-soluble glycoprotein with hypoglycaemic and insulin-sensitizing signals; human data limited to pilots/case reports.
Review Konno 2001 ✓ PubMed
Case report: type 2 diabetic on glyburide adding maitake SX-fraction saw fasting glucose fall from 248 to ~90 mg/dL and HbA1c 11.5% to 5.2%.
Review Chan 2009 ✓ PubMed
Review of beta-glucans on human immune/cancer cells: maitake-type beta-glucans activate NK cells, macrophages and dendritic cells in vitro.
8 sources cited · 8 verified Search all studies on PubMed ↗

Common questions about Maitake

What is Maitake used for?

Maitake is most often taken for Immune cell activation, May lower blood sugar, May support insulin sensitivity, Adjunct interest in cancer care. Culinary mushroom studied for immune and blood-sugar support.

Does Maitake work — what does the evidence say?

Preliminary evidence. Early or small human trials; promising but not yet conclusive. Maitake is an edible mushroom whose beta-glucan extracts (D/MD-fraction) and an SX-fraction glycoprotein are sold for immune and metabolic support. The strongest human work is a Memorial Sloan Kettering phase I/II trial in 34 breast-cancer survivors, where oral extract significantly altered immune parameters (p<0.0005) but unpredictably — intermediate doses sometimes enhanced and sometimes suppressed function. A phase II trial in 18 myelodysplastic-syndrome patients raised basal neutrophil (p=0.005) and monocyte (p=0.021) activity. An open PCOS trial reported ovulation in ~77% on maitake extract, and small diabetes pilots and case reports describe fasting-glucose drops. A 2009 systematic review concluded human evidence remains too sparse and uncontrolled to confirm efficacy, calling for randomized trials. So maitake is promising mechanistically and well tolerated, but not yet proven to improve any clinical outcome.

What is the typical dose of Maitake?

No established dose; trials used standardized liquid extract ~1–5 mg/kg twice daily, or culinary powder 3–7 g/day; quality and fraction content vary widely.

Is Maitake safe? Any cautions or side effects?

Maitake is generally well tolerated as food and in short trials, with occasional GI upset; people allergic to mushrooms should avoid it. A case report links maitake to a raised INR in a patient on warfarin, so it may potentiate anticoagulants. Because extracts can lower blood glucose, combining with insulin or other antidiabetic drugs risks hypoglycemia and warrants monitoring. Safety in pregnancy, breastfeeding and long-term use is unstudied.

How many studies support Maitake?

NutriDex cites 8 sources for Maitake, graded "Preliminary".

Does Maitake interact with any medications?

Yes — known or theoretical interactions include: Diabetes drugs (insulin, metformin) (caution). This is educational and not exhaustive; always check with your doctor or pharmacist before combining Maitake with any medicine.

Cite this page
APA

Peh, D. (2026). Maitake (Grifola frondosa): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 26 Jun 2026, from https://nutridex.info/s/maitake

BibTeX
@misc{nutridex_maitake,
  author       = {Peh, Daryl},
  title        = {Maitake (Grifola frondosa): Benefits, Dosage, Side Effects \& Evidence},
  year         = {2026},
  howpublished = {NutriDex --- The Supplement Research Compendium},
  url          = {https://nutridex.info/s/maitake},
  note         = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-06-26}
}

For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.

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