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.
Outcome
Evidence
Effect
Studies
Modulation of immune cell activityTwo small phase I/II trials altered immune markers, but breast-cancer dose-response was non-monotonic (sometimes suppressed).
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.
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.
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 9 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 16 Sept 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 2026-09-16}
}
For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.