Maitake
Summary
Maitake is an edible mushroom sold as beta-glucan extracts. Small uncontrolled trials in people with cancer or a bone-marrow disorder found changes in lab immune measures, some up and some down (grade D). One open trial in PCOS compared it with a fertility drug, and a 2026 trial tested maitake bread for colds. No large placebo-controlled trial shows a health benefit.
Key facts
- The edible mushroom Grifola frondosa; supplements are polysaccharide (beta-glucan) extracts, often standardized to proteoglycans[1][2][5]
- In 18 people with low-risk myelodysplastic syndrome, 12 weeks of maitake extract raised lab measures of neutrophil and monocyte function; there was no placebo group[1]
- In 34 women after breast cancer treatment, rising doses raised some immune measures and lowered others[2]
- In a 2026 placebo-controlled trial, bread containing either of two maitake strains did not change how often healthy adults caught colds; one strain was linked to fewer days of fever and runny nose (and of sore throat in young adults)[4]
- 3 graded human outcomes on this page
- October 11, 2026
How it works
ProposedMaitake beta-glucans are thought to act on innate immune cells such as neutrophils, monocytes and dendritic cells. In people, measured effects on these cells have gone in both directions depending on dose.[1][2][4]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| PCOS | Grade C | Mixed | RCT · n = 72 · 2010 | 1 row |
| Immune markers | Grade D | Mixed | Open-label · n = 34 · 2009 | 2 rows |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Ovulation in polycystic ovary syndrome, compared with clomiphene | Mixed | Grade C | RCT · n = 72 · 2010 Women with PCOS (open-label, randomized to maitake or clomiphene) Form: Maitake SX-fraction extract · Dose: Dose not stated in the abstract · Duration: Up to 12 weeks Ovulation by patient: 76.9% with maitake vs 93.5% with clomiphene (not significant); by cycle, maitake was lower (41.7% vs 69.9%). | 21034160 (opens PubMed)Source [3] |
| Immune measures in blood after breast cancer treatment | Mixed | Grade D | Open-label trial · n = 34 · 2009 Postmenopausal women free of disease after breast cancer treatment Form: Maitake liquid polysaccharide extract · Dose: 0.1 to 5 mg/kg twice a day (sequential dose-escalation cohorts) · Duration: 3 weeks No dose-limiting toxicity; some immune measures rose and others fell, with no simple dose response. | 19253021 (opens PubMed)Source [2] |
| Neutrophil and monocyte function in myelodysplastic syndrome | Improved | Grade D | Open-label trial · n = 18 · 2015 Adults with low- or intermediate-1-risk myelodysplastic syndrome (21 enrolled) Form: Maitake polysaccharide extract · Dose: 3 mg/kg twice a day · Duration: 12 weeks Lab measures of neutrophil and monocyte function rose; well tolerated, with asymptomatic eosinophilia in 4 people. | 25351719 (opens PubMed)Source [1] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Fruiting-body extract standardized to proteoglycans (D-fraction / PD-fraction) | Varies[1][2] | No human absorption data comparing products in our sources.[1][2] | Generally well tolerated in the cited trials; nausea, joint swelling, rash and eosinophilia were reported in a few people.[1][2] | Immune lab markers (cancer and bone-marrow patients) |
| Maitake SX-fraction extract | Varies[3] | No human absorption data in our sources.[3] | No adverse effects reported in the abstract.[3] | Ovulation in PCOS |
Studied doses
Doses studied in human trials ranged from 0.1 to 5 mg of maitake extract per kg of body weight twice a day, for 3 to 12 weeks.[1][2]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
None found in our sources.
Who should be careful
- People with cancer or on cancer therapy
- In breast cancer survivors, maitake lowered some immune measures as well as raising others, so effects are not predictably helpful. Discuss with your oncology team.[2]
- People trying to conceive with PCOS
- The only PCOS trial was open-label and compared maitake with clomiphene; it is not a substitute for fertility care.[3]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Frequently asked questions
Does maitake boost the immune system?
It changes immune lab measures, but not always upward: in one trial some measures rose and others fell. No large trial shows fewer infections.[1][2][4]
What is maitake D-fraction?
A maitake extract standardized to protein-bound beta-glucans (proteoglycans). The trials we cite used maitake polysaccharide extracts.[1][2][5]
Does maitake help with PCOS?
One open-label trial found ovulation rates with maitake extract that were similar per patient but lower per cycle than clomiphene. There was no placebo group.[3]
Can maitake help with colds?
In a 2026 placebo-controlled trial, maitake bread did not change how often people caught colds; one strain cut some symptom-days.[4]
Sources
- [1]Maitake mushroom extract in myelodysplastic syndromes (MDS): a phase II study.. Cancer Immunol Immunother, 2015. open-label
- [2]A phase I/II trial of a polysaccharide extract from Grifola frondosa (Maitake mushroom) in breast cancer patients: immunological effects.. J Cancer Res Clin Oncol, 2009. open-label
- [3]Maitake mushroom (Grifola frondosa) extract induces ovulation in patients with polycystic ovary syndrome: a possible monotherapy and a combination therapy after failure with first-line clomiphene citrate.. J Altern Complement Med, 2010. RCT
- [4]Maitake mushroom supplementation modulates upper respiratory symptoms and immune responses in healthy adults: a randomized, double-blind, placebo-controlled trial.. Food Funct, 2026. RCT
- [5]Maitake D-Fraction: Supplement Facts. Supersmart, 2026. label
What changed
- First draft. Every PMID checked against NCBI E-utilities (title, year and journal taken from the PubMed record) and abstracts read for each cited row. Supersmart Maitake D-Fraction was out of stock when checked on 2026-10-11, so no product card is shown. Self-reviewed in a second strict pass, then checked by an independent adversarial fact-check against the PubMed abstracts and live product pages. No credentialed medical reviewer yet.