Maitake (Grifola frondosa)

Known as "hen of the woods," maitake is both a prized culinary mushroom and a long-studied source of immune-active polysaccharides (the D-fraction and MD-fraction).

Not medical advice. For education only. If you take diabetes medication, talk to your doctor before using maitake extracts — see Safety below.

What the evidence shows

Preclinical and small human studies suggest maitake's polysaccharide fractions can modulate immune-cell activity, and a small human report found a hypoglycaemic (blood-sugar-lowering) effect in people with type 2 diabetes. Evidence in cancer patients (as an adjunct, alongside conventional treatment) is preliminary — promising cell and animal data, limited robust human trials.

Evidence level: preliminary; the blood-sugar effect is the best-documented human signal.

How it's used

Culinary fresh/dried mushroom, powder, capsules, and standardised D-fraction extracts.

Safety

Because maitake can lower blood glucose, combining concentrated extracts with insulin, sulfonylureas, metformin or SGLT2 inhibitors carries a theoretical risk of hypoglycaemia — monitor blood sugar closely and discuss with your prescriber. It may also have mild blood-pressure-lowering and anticoagulant effects, so use caution alongside blood-pressure medication or blood thinners. Being immune-active, use caution with immunosuppressants. Avoid concentrated extracts in pregnancy and breastfeeding (insufficient data).

Quality notes

Look for standardised D-fraction or MD-fraction extracts with a published beta-glucan percentage and third-party COA, rather than generic "maitake powder."

Sources

Explore the other medicinal mushrooms or our full plant catalogue.