Lentinan

botanical
Best with a meal

What is it

Lentinan is a beta-1,3-glucan polysaccharide isolated from the shiitake mushroom (Lentinula edodes). It is used as an injectable immunomodulator in Japan for cancer treatment adjunct and is sold orally as an immune supplement.

Evidence for 2 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Cancer adjunct (injectable, Japan)

Good

Several Japanese RCTs show modest survival benefit when added to chemotherapy in gastric cancer.

Immune support (oral)

Limited

Small studies suggest oral beta-glucans may modulate immune markers; clinical outcomes data is limited.

How it works

Lentinan is a high-molecular-weight beta-glucan that binds pattern-recognition receptors (dectin-1, complement receptor 3) on innate immune cells, including macrophages, neutrophils and natural killer cells. This activation stimulates cytokine production, enhances phagocytosis, and may improve antitumor immune responses. The injectable form has been used in Japan as an adjunct to chemotherapy for gastric cancer with modest survival benefit in clinical trials. Oral bioavailability of large beta-glucans is limited, though some immune effects have been reported with oral preparations.

Dosage

Injectable: typically 2 mg twice weekly under medical supervision. Oral supplements: 1-10 mg/day or higher of shiitake or beta-glucan extracts; dose depends on product.

When and how to take it

Oral supplements: typically with meals once or twice daily. Injectable form is administered per medical protocol.

2 commercial forms

Injectable lentinan (medical)

Direct delivery.

Used in Japan as cancer adjunct.

Oral shiitake / lentinan supplement

Limited absorption of large polysaccharides.

Common immune-support form.

Safety

Injectable lentinan is generally well tolerated; mild flu-like symptoms or allergic reactions can occur. Oral supplements rarely cause significant side effects.

Who should be cautious

Avoid in pregnancy, breastfeeding, autoimmune diseases on immunosuppressants, and in mushroom allergy.

Interactions

Potential interactions with immunosuppressants (theoretical reduction of effect). May enhance effects of immune-modulating therapies.

Food sources

FoodAmount%DV
Shiitake mushrooms100 g cooked—

Frequently asked questions

Is oral lentinan as effective as the injectable form?⌄

Oral bioavailability is limited; the strong clinical evidence is for the injectable form.

Can I get lentinan from eating shiitake?⌄

Yes, in small amounts, as part of regular shiitake mushroom consumption.

References

  • Lentinan on Wikidata — Wikidata link
  • Lentinan (ChEBI:31770) — ChEBI link
  • Lentinan (PubChem CID 37723) — PubChem link
  • Lentinan on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link
  • Research on Lentinan (PubMed search) — PubMed link

Track Lentinan with Pilora

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.