IngredientsTrametes versicolor (L.) Lloyd is the currently accepted scientific name for the fungus commonly known in the Western world as Turkey Tail. Originally described in 1753 by Carl Linnaeus, who gave it the binomial name Boletus versicolor, it was renamed Trametes versicolor by the Czech mycologist Albert Pilát in 1939. The species belongs to the kingdom Fungi, phylum Basidiomycota, class Agaricomycetes, order Polyporales, and family Polyporaceae.
Synonyms of Trametes versicolor are numerous and include Boletus versicolor L., Poria versicolor (L.) Scop., Agaricus versicolor (L.) Lam., Polyporus fuscatus Fr., Polyporus versicolor (L.) Fr., Polystictus azureus Fr., Coriolus versicolor (L.) Quél., and Polystictus versicolor (L.) Cooke. The synonym Coriolus versicolor remains widely encountered in the older pharmacological and clinical literature, particularly in publications concerning the polysaccharide extracts PSK and PSP. Readers should note that nearly all the published literature in this field is available under the name Coriolus versicolor (Trametes versicolor).
The genus name Trametes derives from the Latin prefix tram- meaning thin, with the implication that fruitbodies of fungi in this genus are thin in cross-section. The specific epithet versicolor means "of several colours," a descriptive name fully justified not only by the variability of colouring from specimen to specimen but also by the presence of several colour bands on the upper surface of a single fruitbody.
Its most common English name is Turkey Tail, and its distinct morphological features include the concentric multicoloured zones on the upper side of the cap (which lacks a stalk) and a spore-bearing polypore underside. The fungus is common in temperate Asia, North America, and Europe, including the UK, where it has been recorded in all regions. Trametes versicolor Lloyd is known by the folk names Turkey Tail in Western cultures, Yun-Zhi in China, and Kawaratake in Japan; whole fruiting bodies are traditionally used for tonic or tea preparation.
Trametes versicolor is characterized by a pore surface with 3–8 pores per millimeter, a feature that differentiates it from other Trametes species, which possess 1–3 pores per millimeter. True Turkey Tail has a thin, flexible cap with micro hairs that feel fuzzy to the touch, and the underside is white or off-white with tiny pores. In contrast, common look-alikes such as Stereum ostrea (False Turkey Tail) have smooth undersides without pores, and Trichaptum biforme (Violet Toothed Polypore) has a toothed underside.
The medicinal value of Trametes versicolor as part of Chinese traditional medicine dates back at least 2,000 years and includes general health-promoting effects, including endurance and longevity.
Records confirm their use in traditional Chinese medicinal practice for removing toxins, treatment of various infections, strengthening, energy increasing, improvement of liver and spleen function, and enhancing the immune response. The Chinese medicinal mushroom was traditionally used to "replenish essence and qi (vital energy)." In oriental countries, T. versicolor mushroom has been utilized for centuries as a preventive measure against a wide range of traditional ailments, including phlegm, pulmonary disorders, and gastrointestinal disorders.
In the Ming Dynasty edition of the Compendium of Chinese Materia Medica, more than 120 strains of T. versicolor have been recorded for their medicinal properties, which were best manifested after chronic use.
In Japan, under the name Kawaratake, the mushroom held a similar role. In the 1970s, Japanese researchers isolated PSK (polysaccharide-K), a compound later approved as an official adjunct in cancer therapy. Since then, Japan has integrated PSK into conventional drug treatment protocols. PSK was approved as a prescription drug for the treatment of cancer in Japan in 1977; by 1987, it accounted for more than 25% of total national expenditure for anticancer agents in Japan.
Medicinal effects have been demonstrated in conventional medicine mainly in treatment of various types of cancers, infections of the respiratory, urinary, and digestive tracts, chronic hepatitis, and rheumatoid arthritis. Some reports also imply traditional usage of polypore mushroom fruiting bodies for increasing memory and improvement of mental functions.
This common polypore mushroom contains a variety of bioactive compounds, the best known of which is the polysaccharide β-glucan. Turkey tail is also the source of the protein-bound β-glucan compounds polysaccharide-K (PSK) and polysaccharopeptide (PSP).
In PSK, roughly 62% of the molecule is polysaccharide and 38% is protein, and PSP is a protein-bound polysaccharide. PSK (Krestin) is a commercially available, highly purified extract of Trametes (Coriolus) versicolor strain CM-101. The major component is β-glucan compounds ranging in size from 94 to 100 kDa.
The main bioactive components of C. versicolor are the polysaccharopeptides (PSPs), which are isolated from the mycelium as well as the fermentation broth. The main sources of these PSPs are China and Japan, producing them from the strains "COV-1" (PSP) and "CM-101" (PSK), respectively. Both products have been approved as medicines primarily as adjuvants in cancer therapy.
Preclinical data point to 1,3-β-D-glucan polysaccharide chains as the main active constituent of T. versicolor. β-Glucans extracted from yeast with an identical β-glucan structure have been shown to have similar immunomodulatory activity to Tv. Trametes versicolor contains a high amount of polysaccharides, including heteroglycan macromolecules which have a high potential for structural variability; glucans have been isolated from both fruiting body and mycelia sources.
HPLC–MS/MS-based studies have identified 38 phenolic compounds belonging to flavonoids (flavones, flavonols, flavanones, flavanols, biflavonoids, isoflavonoids) and hydroxy cinnamic acids. Although ethanol and methanol extracts are generally the richest sources of these phenolic compounds, water extracts were also shown to contain considerable amounts of baicalein, baicalin, quercetin, isorhamnetin, catechin, amentoflavone, p-hydroxybenzoic acid, and cyclohexanecarboxylic acid (in μg/g dry weight). The biological activities of the water extracts of C. versicolor, especially in the antioxidant area, must therefore account for the cumulative effects of the phenolic compounds; however, these compounds are not established as the main components of the fungus, and further research is required to establish their potential contribution to the known biological activities.
Phenolic compounds in T. versicolor include p-hydroxybenzoic acid (113.16 ± 0.22 μg/g dry weight), protocatechuic acid (10.07 ± 0.54 μg/g dry weight), vanillic acid (5.21 ± 0.10 μg/g dry weight), and homogentisic acid (1.24 ± 0.15 μg/g dry weight).
Trametes versicolor consists of bioactive compounds including terpenoids and sterols with anti-inflammatory properties. The ethanol extract of Trametes versicolor has tested positive for terpenoids, steroids, glycosides, flavonoids, carbohydrates, and amino acids.
Research has characterized an exopolysaccharide released in the culture filtrate of T. versicolor and named it Tramesan. Its ability to trigger an antioxidant response in different biological systems (human cell lines, plants, and fungi) has been reported.
PSK, a natural product extracted from medicinal mushroom Trametes versicolor, has been identified as a selective and potent TLR2 agonist. The ability of PSK to activate dendritic cells and T cells is dependent on its ability to stimulate Toll-like receptor 2 (TLR2). Fractionation of PSK further led to the identification of two motifs: a β-glucan recognised by the Dectin-1 receptor and a lipid fraction with agonistic activity towards TLR2.
One of the established recognition sites for the polysaccharides is the toll-like receptors (TLRs), of which effects via TLR4 are well-documented. In mouse peritoneal macrophages, the expression of cytokines and NF-κB activation by PSP was shown to be coupled with TLR4 activation. Furthermore, the induction of TNF-α and IL-6 secretion by PSP via TLR4 has also been well established and correlated with its effect on NF-κB p65 transcription and phosphorylation of c-Jun. The expression of both TLR4 and TLR5 by PSP was shown in PBMCs of human origin, while TLR9 and TLR10 appear to be downregulated.
PSK is a TLR2 agonist that inhibits tumor growth via stimulating CD8 T cells and NK cells; PSK is still considered a mixture, and its full molecular mechanism is not completely elucidated.
C. versicolor polysaccharides, including PSP and PSK, have been shown to demonstrate anti-cancer effects in vivo following oral administration. The well-established mechanism of the anti-cancer effect by C. versicolor is via immunostimulant action, as evidenced by the ability to increase the production of cytokines such as IL-12, which is Th1-related.
Various mechanisms of the antitumor action of PSK have been reported, including immunomodulation — enhancing NK cell, cytotoxic T lymphocyte, and lymphokine-activated killer cell activities — and direct damage to cancer cells. PSK has been reported to be an immune modulator, inducing gene expression of IL-8 in peripheral blood mononuclear cells (PBMC) after oral administration, stimulating T-cell proliferation, and improving the function of CD4+ T cells in gut-associated lymphoid tissue.
The small-molecule polysaccharide peptide musarin, derived from Trametes versicolor, acts as a tyrosine kinase inhibitor to suppress the growth of colorectal cancer stem-like cells, downregulating the EGFR-Ras signaling pathway, including EGFR, p-Akt, and cyclin D1. The EGFR signaling pathway is thereby quenched by musarin-modulated phosphorylation of specific EGFR sites, inhibiting overall EGFR activity and limiting proliferation of the CSC-like CD24+CD44+ HT29 subpopulation.
Polysaccharopeptides (PSPs) are among the main bioactive constituents of Trametes versicolor. Research has found that enzymatic hydrolysates of T. versicolor polysaccharopeptides demonstrated potent antioxidant activity, with half-inhibitory concentrations in metal chelating assay, ABTS and DPPH radical scavenging tests of 0.83 mg/mL, 0.14 mg/mL, and 0.52 mg/mL, respectively.
Fermentation of PSP increased the concentration of organic acids (lactate and short-chain fatty acids), decreased pH, and induced β-galactosidase and β-glucosidase activities. The genera of the human microbiota that are promoted by fructooligosaccharides (FOS) and other prebiotics are also stimulated by the Trametes versicolor extract PSP, indicating that Trametes versicolor contains putative prebiotic agents that alter human gut microbiota and pH.
Additionally, T. versicolor polysaccharides enhanced the growth of butyrate-producing bacteria via the buk and but pathways, accompanied by an increase in short-chain fatty acids (SCFAs), especially butyrate.
The medicinal effects of turkey tail and its extracts have been studied both preclinically and clinically, including studies on the immunomodulatory, antioxidative, prebiotic, and anticancer effects. The bulk of the clinical data on turkey tail mushroom comes from trials in people with cancer.
The application of PSK in gastric cancer — Stage II/III — studied using a large group of 138 patients — further revealed a relapse-free survival rate after post-operation or when compared to oral fluorinated pyrimidine anti-metabolites alone or in combination. When used as an adjuvant agent, PSK enhanced immune response in vivo and improved survival rates in patients with gastric and colorectal cancers.
The Cochrane Collaboration conducted a systematic review to assess the effects of adjunctive Coriolus versicolor (Trametes versicolor) and its extracts on adverse effects and on survival during colorectal cancer treatment (chemotherapy and radiotherapy). The review included randomised controlled trials (RCTs) in adult participants with a confirmed diagnosis of colorectal cancer, in addition to conventional treatment. Interventions included any preparation — raw, decoction, capsule, tablet, tincture, extract, injection — using any part of the fungus in any dose or regimen. The Cochrane Review found low-certainty evidence of a small 5-year survival benefit when PSK is added to standard treatment.
The systematic review and meta-analysis by Eliza et al. assessed the survival outcome in cancer patients from 13 clinical trials on C. versicolor. They reported an impressive result showing a significant survival advantage when compared with standard conventional anti-cancer agents alone; a 9% absolute reduction in 5-year mortality was recorded, with one additional patient alive for every 11 patients treated. A better 5-year survival rate in patients receiving combination treatment was reported in cases of breast cancer, gastric cancer, or colorectal cancer.
A separate systematic review and meta-analysis of RCTs published in Frontiers in Pharmacology found more nuanced results. In vitro studies suggested that both C. versicolor (Yun Zhi) and Ganoderma lucidum (Ling Zhi) extracts — for instance, polysaccharide krestin (PSK) and polysaccharide peptide (PSP) in C. versicolor — possess selective cytotoxic activity against certain tumor cells. However, at the RCT meta-analysis level, results were associated with lower risk of mortality in gastric cancer (HR: 0.74; 95% CI: 0.62, 0.87; P = 0.001; four trials) and nasopharyngeal carcinoma (HR: 0.68; 95% CI: 0.56, 0.84; P < 0.001; two trials). However, no statistically significant differences were found in breast cancer, colorectal cancer, esophageal cancer, hepatocellular carcinoma, NSCLC, or rectal cancer across the available RCT data.
In a randomized study of 158 esophageal cancer patients, the survival of the radiochemotherapy plus Krestin (PSK) group (3,000 mg/day for 12 weeks) was significantly better than that in the group receiving radiochemotherapy alone.
A double-blind, placebo-controlled randomised trial employed 34 patients who had completed conventional treatment for advanced non-small cell lung cancer. They showed that PSP capsules of 340 mg each, taken 3× daily for 4 weeks, could lead to an improvement in blood leukocyte and neutrophil counts, as well as serum IgG and IgM.
Orally administered preparations from the Trametes versicolor mushroom have been hypothesized to improve immune response in women with breast cancer after standard chemotherapy and radiotherapy. A Phase I, two-center, dose escalation study was conducted to determine the maximum tolerated dose of a Tv preparation when taken daily in divided doses for 6 weeks after recent completion of radiotherapy. Eleven participants were recruited and nine women completed the study; each cohort comprised three participants given one of three doses of Tv (3, 6, or 9 grams). Nine adverse events were reported (7 mild, 1 moderate, and 1 severe), suggesting that Tv was well tolerated. Immunological results indicated trends in increased lymphocyte counts at 6 and 9 grams/day, increased natural killer cell functional activity at 6 grams/day, and dose-related increases in CD8+ T cells and CD19+ B cells, but not CD4+ T cells or CD16+56+ NK cells. These findings show that up to 9 grams/day of a Tv preparation is safe and tolerable in women with breast cancer in the post-primary treatment setting.
PSK is approved for cancer therapy use in Japan as an adjunct but is not approved by the FDA or EMA for cancer treatment. In the U.S., PSK/PSP products are sold as dietary supplements without indication claims for cancer. Most trials predate modern oncology standards, with variable randomization, blinding, and control conditions; extracts and dosages are heterogeneous across studies. Many trials were conducted prior to contemporary chemotherapy regimens. Evidence quality ranges from low to moderate, with limited large, rigorously controlled Phase III data outside Japan.
More than 270 recognized species of mushrooms are known to have specific immunotherapeutic properties. Of these, 50 nontoxic mushroom species have yielded potential immunoceuticals in animal models, and of these, 6 species have been studied in human cancers. Of these six, one medicinal mushroom, Tv, has been studied in Phase I, II, and III randomized clinical trials in stomach, colorectal, esophageal, and breast cancer patients. These Japanese and Korean clinical data provide support for the hypothesis that immunomodulation can influence the clinical course in cancer.
Trametes versicolor contains immunomodulatory polysaccharides such as PSK and PSP, which not only enhance host immune surveillance but also mitigate tumor burden through macrophage and natural killer (NK) cell activation. Combining PSK with docetaxel in a murine model induced significantly higher tumor suppression than either treatment alone, including a reduction in tumor proliferation and enhanced apoptosis; combined PSK and docetaxel treatment led to a lower decrease in the number of white blood cells than docetaxel alone, accompanied by increased numbers of tumor-infiltrating CD4+ and CD8+ T cells.
A randomized clinical trial compared the effects of the prebiotic polysaccharopeptide from Trametes versicolor to those of the antibiotic amoxicillin on the human gut microbiome. Twenty-four healthy volunteers were randomized to receive PSP, amoxicillin, or no treatment (control). Stool specimens were analyzed using bTEFAP microbial ecology methods on seven occasions over 8 weeks. The conclusions were that the microbiomes of healthy individuals show substantial diversity but remain stable over time; the antibiotic amoxicillin alters the microbiome with recovery taking several weeks, while PSP from T. versicolor acts as a prebiotic to modulate human intestinal microbiome composition.
Research has demonstrated preferential support by T. versicolor for beneficial bacteria such as Bifidobacterium and Lactobacillus species. The study revealed that PSP administration led to clear and consistent microbiome changes characteristic of prebiotic activity; despite the natural diversity of human microbiomes, researchers observed strong clustering among subjects receiving PSP, indicating consistent and predictable effects on microbial communities.
Animal research (high-fat diet mice) found that T. versicolor polysaccharides also restored disorganization of intestinal fungi and enhanced the growth of butyrate-producing bacteria, accompanied by an increase in short-chain fatty acids (SCFAs), especially butyrate. This body of evidence is preliminary; the human clinical prebiotic trials are small, and animal microbiome data cannot be directly extrapolated to humans.
This mushroom contains an abundance of physiologically bioactive compounds, most notably β-glucan polysaccharides, which are responsible for antioxidant, neuroprotection, hypolipidemic effects, immune-modulating effects, and anticancer effects. Aqueous extracts of T. versicolor expressed potent antioxidant scavenging potential, including the highest activity in the DPPH assay (IC50 = 5.6 μg/mL) and hydroxyl radical scavenging (IC50 = 0.6 μg/mL). The mechanistic and clinical evidence for antioxidant benefit in humans specifically remains largely indirect and based on preclinical and in vitro studies.
Trametes versicolor (formerly Coriolus versicolor) has been found to have various biological activities, including hepatoprotective, anti-inflammatory, antioxidant, anti-genotoxic, immunoregulatory, anti-tumor, and anti-viral abilities. A commercial product of Tv intracellular polysaccharopeptides, PSK, is consumed as a functional food to prevent and alleviate hyperglycemia in China and Taiwan. Animal research suggests that T. versicolor polysaccharides have the potential to counteract hyperlipidemia-associated intestinal flora disorders and improve lipid metabolism. Clinical human evidence for antidiabetic or lipid-lowering effects remains limited to preclinical and animal data; no large, well-controlled human clinical trials on these specific endpoints have been reported in the sources reviewed.
Trametes versicolor has also been revealed to have wound healing, antidiabetic, antimicrobial, antifibrotic, neurotrophic, and anti-inflammatory effects among other therapeutic efficacies. Extensive and controlled in vitro research has also reported antiviral and antioxidant activity of polysaccharopeptides isolated from Trametes spp. fruiting body extracts. Across these domains, evidence is largely preclinical (in vitro or animal), and robust human clinical trial data are not yet available.
The following dosages appear in peer-reviewed published research. They are not treatment recommendations but are reported solely as documented in those sources.
Overall tolerability in clinical settings has been documented by several research groups. Compared to most herbal products, safety research on mushroom products tends to be more robust, and many large-scale clinical trials of medicinal mushroom compounds have not revealed significant adverse events or drug-drug interactions. Eleven Phase I, II, and III clinical trials in stomach, colorectal, esophageal, and breast cancer patients found immunomodulatory benefits with Tv treatment without significant adverse effects.
Despite widespread traditional use and popularity, comprehensive toxicological assessments, particularly of whole mushroom powders, remain limited. Toxicity testing of T. versicolor mycelial biomass and primordia (Organic Turkey Tail M2-101-03 powder) was conducted to evaluate whether the material causes acute toxicity, subchronic toxicity, and genotoxicity in rats, following OECD guidelines. A safe profile of Coriolus versicolor biomass for human consumption can be inferred from the absence of any remarkable adverse effects in rats.
A 28-day oral safety evaluation of extracellular polysaccharopeptides in mice found that clinical observations, growth, food consumption, histopathological examination, and clinical biochemical analyses revealed no adverse effects; there were no significant differences in the results of target organ weights, hematological analyses, and urinalysis examination among groups.
In the Phase I breast cancer clinical trial, nine adverse events were reported (7 mild, 1 moderate, and 1 severe), suggesting that Tv was well tolerated. The trial was a small dose-escalation study (n=9 completers) and was not powered to definitively characterize rare adverse events.
Radiolabelled PSK or its metabolites are excreted in the urine and faeces with 86% excreted within 24 hours. Adverse interactions between Coriolus versicolor mushroom and herbs or drugs have not been reported except for a potential interaction with cyclophosphamide.
C. versicolor polysaccharides, including PSP and PSK, have been shown to demonstrate anti-cancer effects in vivo following oral administration. The rapid urinary and fecal excretion of PSK (86% within 24 hours) indicates relatively rapid clearance, though detailed pharmacokinetic data in humans from the available sources is limited.
PSK is approved for cancer therapy use in Japan as an adjunct but is not approved by the FDA or EMA for cancer treatment. The possibility of immunostimulatory effects theoretically warrants attention in individuals with autoimmune conditions or organ transplants who rely on immunosuppression, though published clinical interaction data for these scenarios are not available in the sources reviewed. Composition may vary based on where mushrooms are grown and the conditions of post-harvest preparation, which has implications for the consistency and potency of commercial products.
Health conditions that Trametes may help support.
Body systems that Trametes may help support.
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