Also known as: Grifola frondosa, Hen of the woods, D-fraction, MD-fraction, Sheep's head
BotanicalEmerging evidence
A large edible bracket fungus, genuinely good to eat and studied for immune and blood sugar effects. Better evidenced as a food than as a supplement.
Typical dose
1.0–3.0 g per day
With food, split across the day
What it is
Grifola frondosa grows in large overlapping clusters at the base of oak trees, sometimes reaching considerable size. The English name hen of the woods describes its appearance; the Japanese name maitake translates as dancing mushroom.
Unlike reishi or turkey tail, maitake is a genuinely good culinary mushroom, widely eaten and cultivated for food as much as for supplements.
The compounds of interest are beta-glucans, particularly a fraction designated D-fraction and its refined version MD-fraction, which are the subject of most of the research. Standardised extracts specify these; whole powder does not.
How it works
Maitake's beta-glucans have a particular branching structure that interacts with receptors on immune cells, modulating their activity. This is the mechanism common to medicinal fungi, with the specifics of the branching pattern being what distinguishes one species from another.
There is also research on effects on glucose handling, with reported influence on how effectively cells respond to insulin.
As with other fungal polysaccharides, a portion reaches the colon intact and is fermented by gut bacteria, contributing a prebiotic effect alongside anything systemic.
What the evidence shows
Human evidence for maitake is limited, and considerably thinner than for turkey tail. Most published work is preclinical.
Small studies have reported changes in immune cell activity following supplementation, and there is preliminary work on blood sugar markers with modest findings.
The fair summary is that maitake is an excellent food with an interesting compound profile and a thin human supplement evidence base. If you like the taste, eating it is a perfectly reasonable way to consume it, and arguably a better use of money than the extract.
Dosing
Common supplemental range is 1 to 3 g daily of extract. Standardised D-fraction products are used at considerably lower amounts, since the active fraction is concentrated.
Judge products on beta-glucan content and on whether they use fruiting body or mycelium grown on grain, as with any mushroom product.
Maitake is also worth buying as food. It cooks well, has a genuinely good flavour, and eating a portion regularly is a legitimate alternative to a capsule if you enjoy it.
At a glance
Common forms
Hot-water fruiting body extract, D-fraction / MD-fraction, Whole mushroom powder, Mycelium on grain, Fresh culinary mushroom
Half-life / duration
Not well characterised; effects accrue over weeks
Timing
With food, split across the day
Competition status
Permitted — not on the WADA Prohibited List
Category
Botanical
Safety and side effects
Maitake is eaten as a food and has a good safety record. Digestive upset is the occasional complaint at higher supplemental doses.
Because it may lower blood sugar, take care if yours is being managed, and speak to your doctor before regular use in that case.
It also has immune-modulating activity, so speak to your doctor if your immune system is being managed. Anyone sensitive to fungi or moulds should avoid it.
Who should avoid it
Take care if your blood sugar is being managed. Speak to your doctor before use if your immune system is being managed or if you take regular medication. Avoid if sensitive to fungi or moulds. Not established at supplemental doses in pregnancy or breastfeeding.
This entry is provided for information only. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Consult a qualified healthcare professional before use if you are pregnant, breastfeeding, taking medication or under medical supervision.
