Split Gill (Schizophyllan)
One of the most common mushroom species on Earth, whose polysaccharide (SPG) is a registered injectable drug in Japan used as an adjunct to radiotherapy for cervical cancer. In Poland and the EU it is neither a registered drug nor a dietary supplement.
Table of contents
TL;DR
One of the most common mushroom species on Earth, whose polysaccharide (SPG) is a registered injectable drug in Japan used as an adjunct to radiotherapy for cervical cancer. In Poland and the EU it is neither a registered drug nor a dietary supplement.
- →In randomized clinical trials in Japan, adding SPG to radiotherapy extended time to recurrence and survival in patients with stage II cervical cancer
- →A multicenter RCT (292 patients) showed a higher rate of complete treatment response with radiotherapy plus SPG
- →A significantly faster recovery of lymphocyte counts after radiotherapy was observed in the group receiving SPG
| Latin name | Schizophyllum commune |
|---|---|
| Family | Schizophyllaceae |
| Active substances | SPG / schizophyllan (sizofiran) — beta-(1→3)-D-glucan with beta-(1→6) branches |
| Form | Intramuscular injectable drug only (Japan) — no oral form |
| Level of evidence | Moderate for the injectable oncology drug; zero for an oral form |
| Interactions | Immunosuppressants — potential antagonism of effect |
| Status | Registered oncology drug in Japan; unavailable as a drug or supplement in Poland and the EU |
Understand
Overview
The split gill (Schizophyllum commune) is a cosmopolitan mushroom, considered one of the most widely distributed fungal species in the world. It grows on dead and decaying wood, forming small (1–4 cm), fan-shaped fruiting bodies with characteristic, longitudinally 'split' gills. In Poland it is considered inedible, though it is traditionally eaten in Mexico, India, and Malaysia.
The scientific significance of the split gill relates almost exclusively to the polysaccharide SPG (schizophyllan, Sonifilan) isolated from its mycelium. Since the 1980s it has been a registered oncology drug in Japan, given by injection alongside radiotherapy for cervical cancer. SPG has never existed as an oral preparation and is not a registered drug in Poland or the EU — nor does it function on the Western market as a dietary supplement.
To put it plainly: for the average reader looking for an 'immunity' supplement, the split gill has no practical use today — the only clinical evidence concerns a drug registered in Japan, given by injection, administered exclusively in hospital settings as an adjunct to radiotherapy and only under an oncologist's supervision. There is no oral form that has been clinically studied or is legally available in Poland or the EU, so buying anything sold under this name as a dietary supplement isn't supported by the cited research.
Where it's found
Schizophyllum commune is one of the most widely distributed mushrooms in the world. It develops as a saprotrophic fungus on dead and decaying deciduous wood. It is common in Poland but considered inedible; in Mexico, India, and Malaysia it is traditionally eaten.
History of use
The split gill's history as a source of a therapeutic substance is purely modern and pharmaceutical: SPG was isolated from its mycelium, and since the 1980s has been a registered oncology drug in Japan used as an adjunct to radiotherapy.
Mechanism of action
SPG is a highly branched beta-(1→3)-D-glucan that activates pattern-recognition receptors (including dectin-1) on macrophages, NK cells, and T cells, boosting cytokine production and supporting the recovery of lymphocyte counts depleted by radiotherapy. In clinical studies the effect was observed solely as an adjunct to radiotherapy.
SPG binds the dectin-1 receptor via the triple helix of its beta-(1→3)-glucan chain with beta-(1→6) side branches, which structurally distinguishes it from simpler beta-glucans — this spatial conformation is considered key to its strong immunostimulant activity. Because the compound was administered exclusively intramuscularly, there is no data on whether an oral form would retain comparable biological activity.
Recognition via the dectin-1 receptor
SPG's highly branched beta-(1→3)-D-glucan chain binds pattern-recognition receptors on macrophages, NK cells, and T cells.
Activation of cytokine production
Stimulation of these receptors boosts secretion of pro-inflammatory and immunostimulant cytokines.
Support for immune system recovery
In clinical studies SPG accelerated the recovery of lymphocyte counts depleted by radiotherapy.
Clinical effect only as a radiotherapy adjunct
All observed benefits were recorded only in combination with irradiation, never as a standalone therapy.
Evidence: moderate — based on 2 studies in this database.
Benefits
Forms & variants
Split Gill (Schizophyllan) comes in several forms that differ in bioavailability and use case — the form you pick genuinely matters for how effective the supplementation is.
Sonifilan / sizofiran (injectable drug)
An oncology drug registered in Japan, given intramuscularly — unavailable in Poland or the EU.
Best for: Not applicable to the Polish market
Practice
Frequently asked questions
No. The only clinically studied form is an injectable drug registered in Japan, unavailable in Poland or the EU.
Dosage & timing
Typical dose
No established oral dose exists. SPG was administered by intramuscular injection exclusively in hospital settings in Japan
Form
Injectable drug — no oral form exists that has been clinically studied or sold as a supplement in Poland or the EU
Dosage information is provided for reference and reflects the ranges used in the cited studies — it does not replace consultation with a doctor or pharmacist. The split gill does not exist in Poland as a dietary supplement.
Best times to take it
- Not applicable — no oral form used independently by consumers
Safety
Side effects & contraindications
Possible side effects
Available data comes from studies of the injectable drug, not from any oral supplement
In a large clinical study, adverse effects were recorded in about 5% of patients — most often fever and injection-site reactions
Contraindications
Autoimmune diseases
Pregnancy and breastfeeding
Not applicable to self-directed use outside of oncological supervision
Interactions
Immunosuppressants — potential antagonism of effect
Is it worth taking?
Who it's for
- In randomized clinical trials in Japan, adding SPG to radiotherapy extended time to recurrence and survival in patients with stage II cervical cancer
- A multicenter RCT (292 patients) showed a higher rate of complete treatment response with radiotherapy plus SPG
- A significantly faster recovery of lymphocyte counts after radiotherapy was observed in the group receiving SPG
Not for
- Autoimmune diseases
- Pregnancy and breastfeeding
- Not applicable to self-directed use outside of oncological supervision
Evidence
Worth knowing
More than 23,000 different mating types ('sexes') have been described in this species.
It's one of the most common mushrooms on Earth, yet its polysaccharide has never made it onto the Western supplement market.
Studies
A multicenter randomized study in 292 patients with cervical cancer showed a significantly higher rate of complete treatment response and faster lymphocyte recovery in the group receiving SPG combined with radiotherapy.
Noda K, et al., Japanese Journal of Clinical Oncology, 1992
Clinical evaluation of schizophyllan combined with irradiation in patients with cervical cancer: A randomized controlled study
Moderate evidenceOkamura K, et al. · Cancer · 1986
A randomized study in 220 patients with cervical cancer — survival time in the SPG group was significantly longer in stage II.
View studyClinical effect of sizofiran combined with irradiation in cervical cancer patients: a randomized controlled study
Moderate evidenceNoda K, et al. · Japanese Journal of Clinical Oncology · 1992
A multicenter RCT in 292 patients showed a significantly higher rate of complete treatment response and faster lymphocyte recovery in the SPG group.
View studySources & bibliography
Citations are illustrative for this demo version and require full bibliographic verification by the editorial team before production publication.
Compare with similar entries
About the authors of this entry
Author
dr Piotr ZielińskiEndocrinologist
Piotr reviews content on hormones, metabolic health and supplement pharmacology.
131 publications on this site
Medical review
dr Anna KowalczykEditor-in-Chief, Molecular Biology
Anna oversees the editorial process and scientific review of every publication in the knowledge base. She previously researched autophagy and mitochondrial biology.
50 publications on this site
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Comments (2)
- KW
Kasia W. 2 weeks ago
Very clearly explained, especially the interactions section — I hadn't seen it laid out this well anywhere else.
- MT
Marek T. a month ago
Are you planning to update this with the newest study from this year? I saw an interesting meta-analysis.