Maitake Mushrooms: Traditional Uses, Human Studies and Extracts

What is maitake?

Maitake is Grifola frondosa, an edible mushroom also called hen of the woods. Supplements include powders and liquid extracts. A concentrated polysaccharide (complex carbohydrate) extract is not the same preparation as cooked mushrooms or a scoop of dried whole mushroom. Modern research covers immune measurements, symptoms during cancer treatment, ovulation in polycystic ovary syndrome (PCOS) and cognition, with different preparations used for each question.

Historical uses and modern preparations

Maitake has a history as both food and herbal medicine. NAFKAM's historical summary^[1] describes Japanese herbal use and Chinese use for upper digestive problems, calming and haemorrhoids. Memorial Sloan Kettering^[2] also lists diabetes and hypertension among traditional uses. These accounts describe what people used maitake for; they do not establish that those treatments worked.

Modern research has moved into specific preparations: concentrated D- and MD-fractions, SX-fraction, liquid fruiting-body extracts and food containing named mushroom strains. That distinction matters when comparing a traditional use with a modern experiment. A result from an extract cannot explain every use of the mushroom as food, and different extracts may contain different proportions of its constituents.

Why do people take maitake?

Maitake can be eaten as food. A supplement marketed as an immune treatment requires a separate decision about evidence, preparation and medicines.

What should a label show?

Check species, whole material versus extract, concentration and actual daily amount. For an extract, concentration should tell you measured extract mass per mL or serving, not only a starting-mushroom equivalent. A drop count alone does not give the extract weight: drops vary with the dispenser and formulation.

“D-fraction” describes a marketed extract fraction, but it is not a standard dose. The label still needs to give the extract amount per serving. “D-fraction” alone does not tell you how much extract you would take.

What are the drawbacks and interactions?

MSK^[2] distinguishes generally safe food use from stronger supplement preparations.

The science behind maitake

Immune measurements and cancer-related research

The 2009 study^[3] enrolled 34 postmenopausal women who were free of disease after breast-cancer treatment. Sequential groups received 0.1, 0.5, 1.5, 3 or 5 mg/kg per dose, twice daily, of a liquid maitake extract for three weeks. The study did not identify an optimal dose. The main questions were side effects and whether participants could continue taking the preparation.

Some laboratory immune measures increased, while others decreased. The response did not simply rise with the dose; intermediate amounts sometimes had larger effects than higher amounts. This is a more complicated finding than “boosts immunity.”

A separate 2015 study in myelodysplastic syndromes^[4], a group of bone-marrow disorders, gave a fruiting-body extract dissolved in glycerin to 21 patients at 3 mg/kg twice daily; 18 completed 12 weeks. There was no untreated patient group. Neutrophils and monocytes are white blood cells involved in immune defense. Some tests of how these cells responded in the laboratory improved, but no participant met the study's criteria for improved blood counts—the number of cells in the blood. Average neutrophil count fell slightly. These laboratory findings did not establish fewer infections. Yukiguni funded the study.

Four patients developed mild eosinophilia, an increase in one type of white blood cell, and one stopped because of persistent mild diarrhea. One patient whose existing disorder was chronic myelomonocytic leukemia progressed to acute leukemia and died. An uncontrolled study cannot determine whether maitake affected that progression.

A 2022 randomized trial^[5] in 141 people receiving chemoradiotherapy for advanced throat cancers reported fewer severe treatment-related adverse events and better quality-of-life scores with a particular maitake D-fraction preparation. It did not establish that maitake treats the cancer.

Respiratory infections and symptoms

In a 2026 placebo-controlled study^[6], healthy adults ate bread containing one of two maitake strains. The overall number of upper-respiratory infections did not differ from placebo, although one strain was associated with fewer days of selected symptoms and changes in laboratory immune measures. Bread containing a named strain is not interchangeable with a retail extract.

PCOS and ovulation

In an open-label 2010 study^[7], 72 women with PCOS were randomized to maitake SX-fraction or clomiphene citrate for up to 12 weeks. The reported analysis included 26 women taking SX-fraction and 31 taking clomiphene. At least one ovulation occurred in 20 of 26 and 29 of 31 women, respectively; that comparison was not statistically significant.

Counting treatment cycles gave a different result: ovulation occurred in 30 of 72 SX-fraction cycles versus 58 of 83 clomiphene cycles, favoring clomiphene. The study therefore does not show that maitake works as well as clomiphene. Its ovulation findings also do not establish a pregnancy or live-birth benefit.

Cognition in older adults

A small 2026 randomized trial^[8] enrolled 48 healthy Japanese adults aged 60–85; 47 completed it. For 18 weeks they ate a daily serving of bread containing 50 g of either Y10M or C5304 maitake, or placebo bread without maitake. Safety was the primary question; cognition was secondary.

Y10M improved scores on the Japanese Montreal Cognitive Assessment compared with placebo. C5304 did not, and neither mushroom group differed from placebo on the other two cognitive tests, MMSE and HDS-R.

Blood sugar and blood pressure

Traditional metabolic uses have not translated into a dependable supplement regimen. The older-adult bread trial found no between-group differences in blood glucose, blood pressure or lipids. Because it studied healthy volunteers, it does not settle whether a particular preparation could help people with diabetes or hypertension.

Bottom line

Maitake has longstanding food and medicinal uses, but its modern studies concern distinct extracts, mushroom strains and outcomes. Immune findings are mixed; the PCOS and cognition results are preliminary, and clinical questions remain open. If you enjoy maitake as food, that is a different choice from taking an extract for a medical purpose. Warfarin and diabetes medicines make individualized review especially important.

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