Turkey Tail, PSK & Immune Defense: Clinical Evidence in Oncology
A research-backed look at Turkey Tail (Trametes versicolor) — one of the most clinically studied medicinal mushrooms. Covers PSK (Krestin) and PSP mechanism of action via TLR2/TLR4, macrophage M1/M2 repolarization, Phase I breast cancer trial outcomes, HPV regression data, and why it's the only mushroom extract approved as an adjunct cancer therapy in Japan.
Source Research Papers
Citations in APA 7 format. All studies were sourced from peer-reviewed journals via Google Scholar. Unfamiliar terms? See the plain-language glossary →
Torkelson, C. J., Sweet, E., Martzen, M. R., Sasagawa, M., Wenner, C. A., Gay, J., Putiri, A., & Standish, L. J. (2012). Phase 1 clinical trial of Trametes versicolor in women with breast cancer. International Scholarly Research Notices Oncology, 2012, 251632. https://doi.org/10.5402/2012/251632
In the first human trial of Turkey Tail in breast-cancer survivors, daily doses were safe and boosted the immune cells that chemo and radiation often weaken.
Lu, H., Yang, Y., Gad, E., Inatsuka, C., Wenner, C. A., Disis, M. L., & Standish, L. J. (2011). Polysaccharide Krestin is a novel TLR2 agonist that mediates inhibition of tumor growth via stimulation of CD8 T cells and NK cells. Clinical Cancer Research, 17(1), 67–76. https://doi.org/10.1158/1078-0432.CCR-10-1763
Lab and mouse work pinned down how Turkey Tail's approved cancer drug PSK switches on the immune system — answering a long-standing 'how does it work' question.
Saleh, M. H., Rashedi, I., & Keating, A. (2017). Immunomodulatory properties of Coriolus versicolor: The role of polysaccharopeptide. Frontiers in Immunology, 8, 1087. https://doi.org/10.3389/fimmu.2017.01087
A deep review of PSP, a Turkey Tail immune compound, and the several ways it appears to rev up the body's defenses against tumors.
Couto, J. S., & Silva, D. P. (2008). Coriolus versicolor supplementation in HPV patients. Proceedings of the 20th European Congress of Obstetrics and Gynaecology.
An early conference report suggested Turkey Tail supplements helped clear HPV infections — interesting, but unproven since it wasn't a controlled trial.
Michalska, A., Szymanowska, U., Kapusta, I., Żurek, N., Nawrocka, A., Różyło, R., Jarocki, P., & Świeca, M. (2025). Antioxidant, anti-inflammatory, and antiproliferative properties of extracted Turkey tail (Trametes versicolor Lloyd) mushroom components microencapsulated with inulin. Food Chemistry, 495, 146348. https://doi.org/10.1016/j.foodchem.2025.146348
Lab work found a way to package Turkey Tail's active compounds so they survive food processing and digestion — a step toward real products, tested only in cells so far.
Shop Related Spores
Laboratory-grade Psilocybe cubensis spore syringes for microscopy research.