Lentinan
Mushroom-derived β-glucan polysaccharide with potent immunomodulatory and antitumor properties approved for cancer therapy in Japan
Written by Michael Carroll — Owner, Director of Research · Reviewed by the Peptide Initiative Research Team · Editorial standards
Suggested dose
1 – 2 mg
Compound profile
Scientific & efficacy data
Immune
Peptide profile
Moderate human trials
Lentinan
1 mg per dose · Once weekly
Molecular formula
(C6H10O5)n (repeating glucose units)
- Mol. weight
- ~500,000 g/mol (varies by preparation)
- CAS number
- 37339-90-5
- PubChem
- Not available (complex polysaccharide)
- Developed · Research ongoing
- Academic research consortium
Multiple research institutions
Amino acid sequence
Not applicable — polysaccharide composed of β-1,3-linked glucose backbone with β-1,6-linked glucose branchesImmune
Lentinan is one of the most extensively studied biological response modifiers, with over 50 years of research demonstrating potent activation of T-cells, NK cells, and macrophages through a thymus-dependent immune mechanism. [3][4] Approved as an adjuvant cancer immunotherapy in Japan since 1985 [2][11].
Healing & Recovery
When combined with chemotherapy, lentinan significantly improves patient quality of life scores including appetite and sleep quality, [1] while reducing chemotherapy side effects and enabling treatment continuity [2][10].
Anti-Aging
Lentinan's antioxidant and anti-inflammatory properties, combined with its immune-enhancing effects, may contribute to healthy aging through improved immune surveillance and reduced chronic inflammation [2].
Dosing
How much do I take?
1 – 2 mg
1 – 2 mg
Covers all 2 documented dose levels · timing · dose-adjustment guidance.
Suitability
Is this right for me?
Best for adjunctive cancer therapy (especially gastric cancer) & immune system enhancement during chemotherapy
Best for
Advanced Gastric Cancer
Lentinan's primary and best-studied indication is as an adjuvant to chemotherapy for unresectable and recurrent gastric cancer. A multi-institutional randomized trial demonstrated significantly extended survival (297 vs 199 days median) and dramatically improved one-year survival rates (49.1% vs 0%) [1].
Lung Cancer Adjuvant Therapy
A 12-year review of clinical studies in China demonstrated that lentinan combined with chemotherapy improves outcomes in lung cancer patients, [9] with a meta-analysis confirming increased chemotherapy efficacy and improved quality of life [10].
Consider alternatives if
Do not use if
Use with caution if
Not sure?
Compare Lentinan with similar peptides to find the best fit for your goals.
Administration
How do I use it?
Intravenous infusion
Route
Subcutaneous injection (into the fatty tissue just under the skin)—allows for consistent absorption and can be self-administered at home after proper training
Best sites
Covers reconstitution · step-by-step technique · storage · a sample daily schedule.
Safety
Is it safe?
4 common side effects · 2 serious
Lentinan is a beta-1,3-glucan polysaccharide (not a true peptide) extracted from shiitake mushroom with a 40-year safety record in Japanese and Asian oncology practice.
Parenteral lentinan shows excellent tolerability as an immune adjuvant [7] with minimal systemic toxicity—hepatotoxicity and nephrotoxicity are essentially absent in clinical use. Fever and localized reactions at injection sites (5-15% of patients) are the documented side effects.
The compound works through pattern recognition receptors (Dectin-1, TLR-2) to enhance NK cell and macrophage function without inducing autoimmunity [2].
Lentinan safety is established through decades of post-market surveillance in Japan where it is approved as an immune-modulating agent combined with chemotherapy in cancer treatment.
[2] Multiple randomized controlled trials in Anticancer Drugs and Journal of Interferon & Cytokine Research document safety and tolerability in immunocompromised and healthy populations.
FDA has not approved lentinan in the US, but extensive clinical experience in Asia supports its use as an immunological adjuvant with favorable safety-to-efficacy ratio.
Common side effects · experienced by some users
Fever and chills
Mild fever and chills may occur during or shortly after IV infusion as part of the immune activation response. This is the most common side effect and reflects lentinan's biological activity [7].
Management: Usually self-resolving within 24 hours. Slow the infusion rate if symptoms occur during administration. Antipyretics may be used for comfort.
Infusion site discomfort
Local discomfort, warmth, or mild pain at the IV infusion site is relatively common and typically resolves after the infusion is complete.
Management: Ensure proper IV line placement. Apply warm compress after infusion if needed. Report persistent pain or swelling to healthcare provider.
Transient fatigue
Mild tiredness or lethargy may occur in the hours or day following infusion, particularly during the first few treatments as the immune system responds to lentinan.
Management: Rest as needed. Fatigue typically diminishes with subsequent treatments. Schedule infusions when rest is possible afterward.
Nausea
Mild nausea may occur during or after infusion. Often difficult to distinguish from chemotherapy-related nausea in cancer patients receiving combination therapy.
Management: Anti-emetics may be used as needed. Taking light meals before infusion may help. Report persistent nausea to your healthcare provider.
Less common
These typically resolve with continued use or dose adjustment.
Stop and seek help if
- Severe or worsening side effects that don't improve with dose adjustment or supportive care
- Signs of an allergic reaction—rash, hives, swelling, or difficulty breathing
- Your healthcare provider recommends discontinuation based on your clinical response
- Development of any new medical condition that may be contraindicated with Lentinan
- Pregnancy or planning to become pregnant (unless specifically approved for use during pregnancy)
- Abnormal lab results or clinical markers that suggest adverse effects
Lentinan should only be started, adjusted, or discontinued under medical supervision. This information is for educational purposes only and does not replace professional medical advice. Never stop a prescribed treatment without consulting your healthcare provider first, as abrupt discontinuation may have consequences.
With other peptides
- Safe:Thymosin Alpha-1 — Both enhance immune function through different mechanisms. Combination may provide synergistic antitumor immunity enhancement. Used together in some Asian oncology protocols.
- Safe:Imunofan — Complementary mechanisms — Imunofan provides antioxidant protection and immune modulation while lentinan activates innate immunity through β-glucan receptor pathways. May reduce chemotherapy toxicity when used alongside lentinan-chemotherapy regimens.
- Safe:BPC-157 — No known interactions. BPC-157 focuses on tissue healing while lentinan targets immune activation. Could potentially support recovery from treatment side effects.
With medications
- Safe:Chemotherapy drugs (cisplatin, tegafur, 5-FU) — Lentinan is specifically designed for use alongside chemotherapy. Clinical trials demonstrate enhanced efficacy and improved patient quality of life when combined. This is the intended clinical use.
- Caution:Immunosuppressants (cyclosporine, tacrolimus) — Lentinan's potent immune-activating effects may counteract the intended immunosuppression. Avoid concurrent use unless specifically directed by a physician.
- Safe:Antiretroviral therapy (HIV) — Clinical trials have combined lentinan with didanosine (ddI) for HIV treatment. The combination was generally tolerated but rapid IV infusion caused adverse effects. Use under close medical supervision.
- Safe:Anticoagulants — Some β-glucans may have mild anticoagulant properties. While not specifically documented for lentinan, caution is advised with concurrent blood-thinning medications.
With supplements
- Safe:Vitamin D supports immune function and may complement lentinan's immunomodulatory effects. Safe to combine.
- Safe:Other mushroom extracts (reishi, turkey tail) — Multiple mushroom-derived β-glucans may provide additive immune effects. While generally safe, excessive immune stimulation is theoretically possible. Use under healthcare provider guidance.
- Safe:Selenium supports antioxidant defense systems and may complement lentinan's anticancer effects. No known negative interactions.
- Safe:Green tea extract (EGCG) — Both have demonstrated anticancer properties through different mechanisms. May provide complementary benefits. No known negative interactions.
Effectiveness
How do I know it's working?
Moderate human trials · first signs week 1-2
Evidence level
Moderate human trials
(Phase 1-2)
Regulatory status
Research compound
Onset of effects
Moderate
(1-2 weeks)
How it works
Lentinan is a complex sugar (polysaccharide) from shiitake mushrooms that activates immune cells called macrophages to recognize and destroy cancer cells and germs.
It works by binding to receptors on immune cells and activating signaling pathways that trigger the immune system's antitumor and antimicrobial responses [2].
The deeper mechanism
Lentinan is a linear β-1,3-glucan with β-1,6 branching that binds primarily to complement receptor 3 (CR3) on macrophages and dendritic cells, but also interacts with dectin-1 (β-glucan receptor) on innate immune cells.
This binding triggers Syk tyrosine kinase activation and downstream NF-κB and MAPK/ERK pathway signaling. [9] Lentinan enhances macrophage antigen presentation through increased MHC-II expression and IL-12 production.
It activates and proliferates T cells through enhanced IL-2 and IL-2 receptor signaling, promoting both CD8+ cytotoxic T cell differentiation and CD4+ helper T cell expansion. Lentinan also activates natural killer (NK) cells and increases their cytotoxic granule release against tumor cells.
[4] In tumor microenvironments, lentinan shifts macrophage polarization from M2 (tumor-promoting) to M1 (antitumor) phenotype through TLR4/NF-κB signaling.
The polysaccharide enhances tumor necrosis factor (TNF-α) and interferon gamma (IFN-γ) production by both innate and adaptive immune cells, creating a sustained antitumor immune response [2].
What to expect
Week 1-2
What you might notice
- Initial immune activation responses (mild fever, chills possible after infusion)
- No visible antitumor effects yet — immune priming is occurring
- Possible mild fatigue as the immune system responds to treatment
What's normal
- Mild flu-like symptoms after first few infusions are normal immune activation signs
- No immediate visible changes in tumor status — this is expected
- Side effects from concurrent chemotherapy may begin to feel slightly more manageable
What's next
- Continue weekly infusion schedule as prescribed
- Blood tests may be ordered to assess immune cell activation markers
- Report any unusual reactions to your oncology team
Week 2-6
What you might notice
- Improved appetite and sleep quality (documented in clinical trials)
- Enhanced energy levels compared to chemotherapy alone
- Blood work may show increased NK cell and T-cell activity
- Potential improvement in overall quality of life scores
What's normal
- Quality of life improvements develop gradually over weeks
- Immune parameters begin shifting toward better antitumor surveillance
- Infusion-related side effects often diminish with continued treatment
What's next
- Continue treatment as part of the ongoing chemotherapy regimen
- Your oncologist will monitor tumor response at scheduled intervals
- Quality of life assessment may be repeated to track improvement
Week 6-12+
What you might notice
- Sustained improvement in quality of life and overall well-being
- Potential tumor response visible on imaging (in combination with chemotherapy)
- Better tolerance of ongoing chemotherapy cycles
- Stronger immune function as measured by laboratory tests
What's normal
- Benefits are cumulative and most meaningful over months of treatment
- Lentinan works best as part of a comprehensive treatment plan with chemotherapy
- Some patients experience sustained immune benefits after completing treatment
What's next
- Your oncologist will determine the optimal duration based on tumor response
- Treatment may continue for multiple chemotherapy cycles
- Long-term immune monitoring may be recommended
Signs it's working
Treatment Response
- Improvement in the primary symptoms or condition being treated
- Positive changes in relevant lab values or clinical markers
- Consistent, stable response to Lentinan over time
- Reduction in symptom frequency or severity
General Well-being
- Improved energy levels and daily functioning
- Better quality of life related to the treated condition
- Manageable or absent side effects indicating good tolerance
- Positive feedback from healthcare provider during check-ups
Not seeing results? Common reasons
- Not at therapeutic dose yet—initial doses are for building tolerance, not maximum effect
- Insufficient time at target dose—most compounds need several weeks to show full benefits
- Inconsistent dosing schedule—regular, consistent use is crucial for optimal results
- Individual variation in response—genetics, metabolism, and other factors affect outcomes
- Underlying conditions or medications interfering with absorption or effectiveness
- Improper storage leading to degraded product—always verify proper storage conditions
Key research
Questions
Frequently asked
Is lentinan a peptide?
No, lentinan is not a peptide. It is a high-molecular-weight β-1,3-glucan polysaccharide with β-1,6 branching, isolated from the shiitake mushroom (Lentinula edodes). [3] With a molecular weight of approximately 500,000 Da, it is a complex carbohydrate polymer. It is included in this database because of its significant role as a biological response modifier in immune-oncology and its clinical importance alongside peptide-based immunomodulators.
Where is lentinan approved for clinical use?
Lentinan was approved in Japan in 1985 as an adjuvant biological response modifier for the treatment of gastric cancer. [11] It has also been approved in China for similar oncological applications. [2] It is not approved by the FDA in the United States or by the EMA in Europe, though clinical trials have been conducted in these regions. In Japan and China, it is used as part of standard oncology protocols for gastric, lung, and colorectal cancer.
Can I just eat shiitake mushrooms instead?
While shiitake mushrooms do contain lentinan, eating whole mushrooms or taking oral extracts provides much lower and less predictable lentinan delivery compared to the purified IV formulation used in clinical trials. Oral bioavailability of intact high-molecular-weight lentinan is limited. Dietary shiitake consumption may provide general health and immune benefits, but should not be considered equivalent to clinical IV lentinan therapy for cancer treatment.
Why must lentinan be given slowly by IV?
Rapid IV infusion of lentinan (under 10 minutes) has been associated with serious adverse events including anaphylaxis and granulocytopenia. [7] The slow drip infusion over 30-60 minutes allows the body to process the large polysaccharide molecules gradually, minimizing the risk of acute immune overactivation and allergic responses. This is why lentinan must always be administered in a clinical setting with trained personnel and emergency equipment available.
How does lentinan compare to other mushroom-based cancer treatments?
Lentinan (from shiitake), PSK/Krestin (from turkey tail), and schizophyllan (from Schizophyllum commune) are the three most clinically studied mushroom polysaccharides. All are β-glucans that activate immune responses. Lentinan is primarily used for gastric cancer, PSK is widely used in Japan for colorectal and gastric cancer, and schizophyllan has been studied for cervical cancer. Each has slightly different structural features that may influence their specific immune-activating profiles [3].
Can lentinan be used alongside conventional chemotherapy?
Yes — this is specifically how lentinan is intended to be used. Clinical trials demonstrate that lentinan combined with chemotherapy (such as tegafur plus cisplatin) [1] provides significantly better outcomes than chemotherapy alone, including longer survival, higher one-year survival rates, improved quality of life, and reduced chemotherapy side effects. [10] Lentinan should never replace chemotherapy but rather complement it as an adjuvant.
What are the risks of lentinan treatment?
Lentinan is generally well-tolerated when administered by slow IV infusion. Common side effects include mild fever, chills, and fatigue as part of the normal immune activation response. Rare but serious risks include anaphylaxis (primarily with rapid infusion), granulocytopenia, and elevated liver enzymes. [7] Treatment should always be administered in a clinical setting where these risks can be managed, and patients should be monitored for at least 30 minutes after each infusion.
Further reading
History & related research
History · since 1969
From ancient mushrooms to modern cancer immunotherapy
Lentinan is a polysaccharide (β-1,3-glucan), not a peptide, extracted from shiitake mushrooms. This high-molecular-weight immune-activating compound bridges thousands of years of Asian traditional medicine with modern oncology.
Read the full history of LentinanReady for the protocol?
Every dosing tier, administration route, timing note, and dose-adjustment rule for Lentinan, on one page.