Herb ·Moderate evidence ·Reviewed May 2026
Colorful bracket fungus with strong immune-modulating research, especially PSK/PSP.
The bottom line
Evidence rating moderate. Most-documented uses: immune modulation, gut microbiome, cancer support (adjunctive). 17 sources indexed (1989–2025), with 4 interaction records on file.
Core mechanism
Polysaccharopeptides PSK and PSP activate NK cells, T cells, and macrophages. Modulate gut microbiome composition. Used adjunctively in cancer care in Japan.11,4
Can take any time
Dosing protocol
Best evidence as cancer adjunct (PSK is a prescription drug in Japan). Generally well tolerated.
Ranked by evidence and value.
Real-world pricing across three quality tiers. Assumes Hot Water / Dual Extract Turkey Tail.
Assumes 1-3 g/day. Vendor basis: iHerb, Vitacost, Amazon marketplace, and specialty mushroom brands; fruiting-body dual extracts price premium. Updated 2026-05-28.
How much you'd eat to match a supplemental dose.
It is usually prepared as tea or extract because the mushroom is tough.
What to test, the optimal window inside the conventional range, and how long a response takes.
Trametes versicolor PSK/PSP polysaccharides (3 g per day) have RCT evidence as adjunct in breast and colorectal cancer for raising NK cell activity and prolonging disease-free survival.11,1
NK functional testing is not standard outside of research and specialty oncology contexts. PSK (Krestin) is licensed as a prescription cancer adjunct in Japan.
Both are beta-glucan-rich medicinal mushrooms commonly combined for complementary immune modulation.
Recommendation: Acceptable to combine for immune support. No special timing needed; people on immunosuppressant therapy should consult a clinician given the immune-modulating activity.
Turkey tail and reishi are both beta-glucan-rich medicinal mushrooms that modulate innate immune cell activity through complementary mechanisms, supporting an additive immunomodulatory effect.
Recommendation: Can be taken together as part of a mushroom blend for immune support. No timing restriction is needed.
Turkey tail polysaccharopeptide (PSP) acts as a prebiotic that favorably shifts gut microbiota composition, complementing the live bacteria delivered by probiotic supplements.
Recommendation: Reasonable to combine; turkey tail can serve as a prebiotic substrate alongside a probiotic. No timing separation is required.
Turkey tail and cordyceps are both immunomodulatory medicinal mushrooms whose polysaccharides support innate immune activity through overlapping receptor pathways, producing an additive effect.
Recommendation: Can be combined in an immune or wellness mushroom stack. No timing restriction is needed.
Numbered references. Citations throughout the page link here.
Systematic review found that polysaccharopeptide (PSK/PSP) from Trametes versicolor used as adjuvant cancer therapy improved survival, immune function markers, and reduced chemotherapy side effects across multiple cancer types.
Meta-analysis found PSK (from Coriolus versicolor) as adjuvant therapy significantly improved overall survival and disease-free survival in colorectal cancer patients when combined with chemotherapy.
Ma Y, Wu X, Yu J et al.. Can polysaccharide K improve therapeutic efficacy and safety in gastrointestinal cancer? a systematic review and network meta-analysis. Oncotarget. 2017
PSP significantly increased Bifidobacterium and Lactobacillus while reducing Clostridium, Staphylococcus, and Enterococcus in healthy volunteers
Turkey tail mushroom demonstrated immune-enhancing properties in breast cancer patients as an adjunct to conventional treatment
Ito K, Nakazato H, Koike A et al.. Long-term effect of 5-fluorouracil enhanced by intermittent administration of polysaccharide K after curative resection of colon cancer. A randomized controlled trial for 7-year follow-up. International journal of colorectal disease. 2004
Ohwada S, Kawate S, Ikeya T et al.. Adjuvant therapy with protein-bound polysaccharide K and tegafur uracil in patients with stage II or III colorectal cancer: randomized, controlled trial. Diseases of the colon and rectum. 2003
Nakazato H, Koike A, Ichihashi H et al.. [An effect of adjuvant immunochemotherapy using krestin and 5-FU on gastric cancer patients with radical surgery (first report)--a randomized controlled trial by the cooperative study group. Study Group of Immuno-chemotherapy with PSK for Gastric Cancer]. Gan to kagaku ryoho. Cancer & chemotherapy. 1989
Kale Bakir E, Deveci Ozkan A, Erman G et al.. Anticancer potential of purified laccase enzyme from Trametes versicolor: specific cytotoxicity against thyroid and endometrial cancer cells. Molecular biology reports. 2025
Systematic review of turkey tail mushroom polysaccharides for reducing adverse effects of cancer treatment in colorectal cancer patients
PSK and PSP polysaccharopeptides activate NK cells, T cells, and macrophages and serve as adjuvant therapy for cancer
15 of 17 preclinical studies supported anticancer effects for PSK through immunomodulation and potentiation of immune surveillance; PSK may extend survival in lung cancer patients
Turkey tail mycelium and fermented substrate showed potent and complementary immune activating properties in vitro
This page is educational. Do not start, stop, or change a supplement or medication based on it without checking with a qualified healthcare professional.
Use this with your stack
Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.
NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.
NutriStack