Grifola frondosa · supplement
Evidence tier: limited
Maitake is Grifola frondosa, an edible mushroom also called hen of the woods because its clusters, at the foot of oak trees, look like a ruffled hen. It is eaten cooked, and is also sold as a powder or in capsules.
Its beta 1,6 glucan, a protein bound polysaccharide, is recognised by immune cells (MSK). The blood sugar effect is supported in animals and in the small PCOS trial, not in a robust human RCT.
Limited, and almost all of it in disease populations. MSK (updated 2026-07-09) summarises immune effects of oral maitake extract in postmenopausal breast cancer patients (PMID 19253021, where the effect went both up and down), better neutrophil and monocyte function in myelodysplastic syndrome (PMID 25351719), and fewer chemoradiotherapy side effects in head and neck cancer (PMID 36070433). A small trial in polycystic ovary syndrome reported ovulation (PMID 21034160). There is no placebo controlled trial in healthy people. The recurring signal is lower blood sugar, which matters most as a medicine interaction.
No agreed supplement dose. The breast cancer trial escalated a liquid extract from 0.1 to 5 mg per kg twice daily for 3 weeks (PMID 19253021); the MDS trial used 3 mg per kg twice daily for 12 weeks (PMID 25351719). Whole maitake is also a food.
Trials ran for weeks, not single doses. Extract fractions are not interchangeable with whole mushroom, so the label should say which one it is. Anyone on diabetes medicine or a blood thinner should check with a pharmacist first, and mention it before surgery. Reported side effect: eosinophilia without symptoms [MSK].
Pregnancy: avoid
Breastfeeding: avoid
Active compounds: beta-1,6-glucan (protein bound polysaccharide), D-fraction / MD-fraction, SX-fraction
Remedies using Maitake · Browse by body system · Check it against what you take
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.