What does the evidence show about Maitake (Grifola frondosa)'s effects?

Read Off Label rates the evidence for Maitake (Grifola frondosa) as Weak and the benefit magnitude as low, producing an overall grade of C+ (5.3/10). D-fraction beta-glucan is the headline molecule and the basis of the immune-adjuvant story.

What safety findings are reported for Maitake (Grifola frondosa)?

Maitake (Grifola frondosa) has a low risk profile in the database. Low (well-tolerated; theoretical hypoglycemia signal with concurrent antidiabetics) Legal status: OTC.

What doses or routes are reported for Maitake (Grifola frondosa)?

500-3000 mg/day fruiting body extract; D-fraction-standardized products available This is context from studies, approved labeling, clinical practice, or documented use; it is not individualized guidance and does not establish safety.

Rankings / Immune & Inflammation

Maitake (Grifola frondosa)

Immune & Inflammation · Medicinal mushroom / beta-glucan

Tier C+

Reviewed by Read Off Label · Last reviewed Jun 8, 2026 · How we grade

beta-glucanotc

5.3 / 10

Tier C+

Ev 3 Bn 2 Sf 9

Bottom line

Read Off Label grades Maitake (Grifola frondosa) as C+ (5.3/10) based on weak evidence, low benefit magnitude, and a low-risk safety profile.

D-fraction beta-glucan is the headline molecule and the basis of the immune-adjuvant story.

Studied, labeled, or reported-use context: 500-3000 mg/day fruiting body extract; D-fraction-standardized products available — OTC; not individualized guidance.

What the evidence says

D-fraction beta-glucan is the headline molecule and the basis of the immune-adjuvant story. Glycemic effect is small but real. Mostly small-trial Japanese literature; Western RCT replication is thin. Standardization to D-fraction or alpha-glucan content matters more than total mushroom weight.

Mechanism

D-fraction beta-glucan (1,6-branched 1,3-glucan); Dectin-1 activation; macrophage and NK cell stimulation; modest insulin-sensitizing effect via SX-fraction (alpha-glucan)

Studied, labeled, or reported dose & route

500-3000 mg/day fruiting body extract; D-fraction-standardized products available

This records doses and routes described in studies, approved labeling, clinical practice, or documented use. It is not individualized guidance and does not establish safety; context changes with indication, formulation, health history, monitoring, and other medicines.

Citations

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Common questions

What does the evidence show about Maitake (Grifola frondosa)'s effects?: Read Off Label rates the evidence for Maitake (Grifola frondosa) as Weak and the benefit magnitude as low, producing an overall grade of C+ (5.3/10). D-fraction beta-glucan is the headline molecule and the basis of the immune-adjuvant story.
What safety findings are reported for Maitake (Grifola frondosa)?: Maitake (Grifola frondosa) has a low risk profile in the database. Low (well-tolerated; theoretical hypoglycemia signal with concurrent antidiabetics) Legal status: OTC.
What doses or routes are reported for Maitake (Grifola frondosa)?: 500-3000 mg/day fruiting body extract; D-fraction-standardized products available This is context from studies, approved labeling, clinical practice, or documented use; it is not individualized guidance and does not establish safety.
How does Maitake (Grifola frondosa) work?: D-fraction beta-glucan (1,6-branched 1,3-glucan); Dectin-1 activation; macrophage and NK cell stimulation; modest insulin-sensitizing effect via SX-fraction (alpha-glucan)

This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.