Medicinal Mushrooms (PDQ®)

NCI PDQ Summaries for Patients

Questions and Answers About Turkey Tail and Polysaccharide-K (PSK)
About This PDQ Summary
General CAM Information
Evaluation of CAM Therapies
Questions to Ask Your Health Care Provider About CAM
To Learn More About CAM



Mushrooms have been used for hundreds of years, mainly in Asian countries, to treat infections. More recently, they have also been used to treat lung diseases and cancer. For more than 30 years, mushrooms used in the practice of medicine have been approved as an addition to standard cancer treatments in Japan and China. In these countries, mushrooms have been used safely for a long time, either alone or combined with chemotherapy.

There are more than 100 types of mushrooms used as medicine in Asia. Some of the more common ones are Ganoderma lucidum (Reishi), Trametes versicolor or Coriolus versicolor (turkey tail), Lentinus edodes (Shiitake), and Grifola frondosa (Maitake).

Mushrooms are being studied to find out if they will stop or slow the growth of tumors. These studies are meant to show how mushrooms affect the immune system and whether they may cause apoptosis (a series of steps in a cell that lead to its death).

The medical action of certain chemical compounds (polysaccharides) in mushrooms is being studied to find out if it has anticancer activity and strengthens the immune system.

This PDQ cancer information summary gives an overview of the use of mushrooms in treating cancer. The following information is for Trametes versicolor, also called Coriolus versicolor (turkey tail):

Sections describing results of clinical trials on other mushrooms will be added over time.

Questions and Answers About Turkey Tail and Polysaccharide-K (PSK)

What is turkey tail?

Turkey tail is a type of mushroom that grows on dead logs worldwide. The name turkey tail refers to its rings of brown and tan which look like the tail feathers of a turkey. Its scientific name is Trametes versicolor or Coriolus versicolor. In traditional Chinese medicine, it is known as Yun Zhi. In Japan it has been known as kawaratake (roof tile fungus). There are many other types of Trametes. Some of them are hard to tell from turkey tail without the use of special testing.

Turkey tail has been used in traditional Chinese medicine for many years for lung diseases. In Japan, turkey tail has been used to strengthen the immune system when given with standard cancer treatment.

The best known active compound in turkey tail is polysaccharide K (PSK). In Japan, PSK is an approved mushroom product used to treat cancer.

How is PSK given or taken?

PSK can be taken as a tea or in capsule form.

Have any preclinical (laboratory or animal) studies been done using PSK?

In laboratory studies, cells are used to find out if a new substance is likely to have any anticancer effects. In animal studies, tests are done to see if a new drug, procedure, or treatment is safe and effective in animals before it is tested in people.

Laboratory and animal studies have tested the effects of PSK on the immune system, including immune cells called natural killer cells and T-cells. See the Laboratory/Animal/Preclinical Studies section of the health professional version of Medicinal Mushrooms for information on laboratory and animal studies done using PSK.

Have any clinical trials (research studies with people) of PSK been done?

PSK (from the mushroom T. versicolor) is an approved mushroom product used to treat cancer in Japan. It has been used as adjuvant therapy in thousands of cancer patients since the mid-1970s. PSK has been safely used for a long time in Japan and few side effects have been reported.

Clinical trials in gastric cancer

Studies show that the use of PSK as adjuvant therapy in patients with gastric (stomach) cancer may help repair immune cell damage caused by chemotherapy and strengthen the immune system. Studies in patients with gastric cancer included the following:

  • A randomized clinical trial in Japan done between 1978 and 1981 included 751 patients who had surgery for gastric cancer and received adjuvant chemotherapy with or without PSK. On average, the patients in the PSK group lived longer than those who received chemotherapy alone. This study found that it might be possible to predict which patients would benefit the most from adjuvant PSK depending on the numbers of granulocytes and lymphocytes in the patient’s blood.
  • In 1994, a study in Japan first suggested that PSK supported the immune system in patients receiving chemotherapy. The study followed patients who had successful surgery for gastric cancer and were given either standard chemotherapy alone or standard chemotherapy with PSK. Patients who received chemotherapy with PSK were found to have improved 5-year disease-free rates and overall survival rates compared with those who did not. Treatment with PSK caused few side effects and the researchers thought the study showed that PSK should be added to chemotherapy in gastric cancer patients who have surgery to remove the cancer.
  • A review published in 2007 combined results from 8 randomized controlled trials in 8,009 patients who had surgery to remove gastric cancers. Patients in the trials were given either standard chemotherapy alone or standard chemotherapy with PSK to strengthen the immune system. The results suggest that PSK and chemotherapy helped patients live longer after surgery.

Clinical trials in colorectal cancer

Studies of PSK as adjuvant therapy for colorectal cancer include the following:

  • PSK was studied in a randomized clinical trial for its effect on the immune system in patients with stage II or stage III rectal cancer. Patients received standard treatment of chemotherapy with radiation therapy, with or without PSK. This study found that PSK increased the number of cancer-killing immune cells and caused anticancer effects in tissue that received radiation therapy.
  • A number of prospective randomized clinical trials showed that patients with colorectal cancer who received adjuvant PSK were less likely to have recurrent cancer and lived longer.

Clinical trials in lung cancer

Studies of PSK as adjuvant therapy for patients with lung cancer include the following:

  • Five nonrandomized clinical trials reported that patients treated with PSK combined with radiation therapy and/or chemotherapy lived longer.
  • Six randomized clinical trials in patients with lung cancer studied PSK given with chemotherapy, compared with chemotherapy alone. The studies showed that patients who received PSK improved in one or more ways, including immune function, body weight, well-being, tumor-related symptoms, or longer survival.

Have any side effects or risks been reported from turkey tail or PSK?

There have been few side effects reported in studies of PSK in Japan.

Is turkey tail or PSK approved by the U.S. Food and Drug Administration (FDA) for use as a cancer treatment in the United States?

The U.S. Food and Drug Administration has not approved the use of turkey tail or its active compound PSK as a treatment for cancer or any other medical condition.

About This PDQ Summary

About PDQ

Physician Data Query (PDQ) is the National Cancer Institute's (NCI's) comprehensive cancer information database. The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries come in two versions. The health professional versions have detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions have cancer information that is accurate and up to date and most versions are also available in Spanish.

PDQ is a service of the NCI. The NCI is part of the National Institutes of Health (NIH). NIH is the federal government’s center of biomedical research. The PDQ summaries are based on an independent review of the medical literature. They are not policy statements of the NCI or the NIH.

Purpose of This Summary

This PDQ cancer information summary has current information about the use of medicinal mushrooms in the treatment of people with cancer. It is meant to inform and help patients, families, and caregivers. It does not give formal guidelines or recommendations for making decisions about health care.

Reviewers and Updates

Editorial Boards write the PDQ cancer information summaries and keep them up to date. These Boards are made up of experts in cancer treatment and other specialties related to cancer. The summaries are reviewed regularly and changes are made when there is new information. The date on each summary ("Date Last Modified") is the date of the most recent change.

The information in this patient summary was taken from the health professional version, which is reviewed regularly and updated as needed, by the PDQ Integrative, Alternative, and Complementary Therapies Editorial Board.

Clinical Trial Information

A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.

Clinical trials are listed in PDQ and can be found online at NCI's website. Many cancer doctors who take part in clinical trials are also listed in PDQ. For more information, call the Cancer Information Service 1-800-4-CANCER (1-800-422-6237).

Permission to Use This Summary

PDQ is a registered trademark. The content of PDQ documents can be used freely as text. It cannot be identified as an NCI PDQ cancer information summary unless the whole summary is shown and it is updated regularly. However, a user would be allowed to write a sentence such as “NCI’s PDQ cancer information summary about breast cancer prevention states the risks in the following way: [include excerpt from the summary].”

The best way to cite this PDQ summary is:

PDQ® Integrative, Alternative, and Complementary Therapies Editorial Board. PDQ Medicinal Mushrooms. Bethesda, MD: National Cancer Institute. Updated <MM/DD/YYYY>. Available at: Accessed <MM/DD/YYYY>.

Images in this summary are used with permission of the author(s), artist, and/or publisher for use in the PDQ summaries only. If you want to use an image from a PDQ summary and you are not using the whole summary, you must get permission from the owner. It cannot be given by the National Cancer Institute. Information about using the images in this summary, along with many other images related to cancer can be found in Visuals Online. Visuals Online is a collection of more than 2,000 scientific images.


The information in these summaries should not be used to make decisions about insurance reimbursement. More information on insurance coverage is available on on the Managing Cancer Care page.

Contact Us

More information about contacting us or receiving help with the website can be found on our Contact Us for Help page. Questions can also be submitted to through the website’s E-mail Us.

General CAM Information

Complementary and alternative medicine (CAM)—also called integrative medicine—includes a broad range of healing philosophies, approaches, and therapies. A therapy is generally called complementary when it is used in addition to conventional treatments; it is often called alternative when it is used instead of conventional treatment. (Conventional treatments are those that are widely accepted and practiced by the mainstream medical community.) Depending on how they are used, some therapies can be considered either complementary or alternative. Complementary and alternative therapies are used in an effort to prevent illness, reduce stress, prevent or reduce side effects and symptoms, or control or cure disease.

Unlike conventional treatments for cancer, complementary and alternative therapies are often not covered by insurance companies. Patients should check with their insurance provider to find out about coverage for complementary and alternative therapies.

Cancer patients considering complementary and alternative therapies should discuss this decision with their doctor, nurse, or pharmacist as they would any type of treatment. Some complementary and alternative therapies may affect their standard treatment or may be harmful when used with conventional treatment.

Evaluation of CAM Therapies

It is important that the same scientific methods used to test conventional therapies are used to test CAM therapies. The National Cancer Institute and the National Center for Complementary and Integrative Health (NCCIH) are sponsoring a number of clinical trials (research studies) at medical centers to test CAM therapies for use in cancer.

Conventional approaches to cancer treatment have generally been studied for safety and effectiveness through a scientific process that includes clinical trials with large numbers of patients. Less is known about the safety and effectiveness of complementary and alternative methods. Few CAM therapies have been tested using demanding scientific methods. A small number of CAM therapies that were thought to be purely alternative approaches are now being used in cancer treatment—not as cures, but as complementary therapies that may help patients feel better and recover faster. One example is acupuncture. According to a panel of experts at a National Institutes of Health (NIH) meeting in November 1997, acupuncture has been found to help control nausea and vomiting caused by chemotherapy and pain related to surgery. However, some approaches, such as the use of laetrile, have been studied and found not to work and to possibly cause harm.

The NCI Best Case Series Program which was started in 1991, is one way CAM approaches that are being used in practice are being studied. The program is overseen by the NCI’s Office of Cancer Complementary and Alternative Medicine (OCCAM). Health care professionals who offer alternative cancer therapies submit their patients’ medical records and related materials to OCCAM. OCCAM carefully reviews these materials to see if any seem worth further research.

Questions to Ask Your Health Care Provider About CAM

When considering complementary and alternative therapies, patients should ask their health care provider the following questions:

  • What side effects can be expected?
  • What are the risks related to this therapy?
  • What benefits can be expected from this therapy?
  • Do the known benefits outweigh the risks?
  • Will the therapy affect conventional treatment?
  • Is this therapy part of a clinical trial?
  • If so, who is the sponsor of the trial?
  • Will the therapy be covered by health insurance?

To Learn More About CAM

National Center for Complementary and Integrative Health (NCCIH)

The National Center for Complementary and Integrative Health (NCCIH) at the National Institutes of Health (NIH) facilitates research and evaluation of complementary and alternative practices, and provides information about a variety of approaches to health professionals and the public.

  • NCCIH Clearinghouse
  • Post Office Box 7923 Gaithersburg, MD 20898–7923
  • Telephone: 1-888-644-6226 (toll free)
  • TTY (for deaf and hard of hearing callers): 1-866-464-3615
  • E-mail:
  • Website:

CAM on PubMed

NCCIH and the NIH National Library of Medicine (NLM) jointly developed CAM on PubMed, a free and easy-to-use search tool for finding CAM-related journal citations. As a subset of the NLM's PubMed bibliographic database, CAM on PubMed features more than 230,000 references and abstracts for CAM-related articles from scientific journals. This database also provides links to the websites of over 1,800 journals, allowing users to view full-text articles. (A subscription or other fee may be required to access full-text articles.)

Office of Cancer Complementary and Alternative Medicine

The NCI Office of Cancer Complementary and Alternative Medicine (OCCAM) coordinates the activities of the NCI in the area of complementary and alternative medicine (CAM). OCCAM supports CAM cancer research and provides information about cancer-related CAM to health providers and the general public via the NCI website.

National Cancer Institute (NCI) Cancer Information Service

U.S. residents may call the NCI Cancer Information Service toll free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 8:00 am to 8:00 pm. A trained Cancer Information Specialist is available to answer your questions.

Food and Drug Administration

The Food and Drug Administration (FDA) regulates drugs and medical devices to ensure that they are safe and effective.

  • Food and Drug Administration
  • 10903 New Hampshire Avenue
  • Silver Spring, MD 20993
  • Telephone: 1-888-463-6332 (toll free)
  • Website:

Federal Trade Commission

The Federal Trade Commission (FTC) enforces consumer protection laws. Publications available from the FTC include:

  • Who Cares: Sources of Information About Health Care Products and Services
  • Fraudulent Health Claims: Don’t Be Fooled
  • Consumer Response Center
  • Federal Trade Commission
  • 600 Pennsylvania Avenue, NW
  • Washington, DC 20580
  • Telephone: 1-877-FTC-HELP (1-877-382-4357) (toll free)
  • TTY (for deaf and hard of hearing callers): 202-326-2502
  • Website:
Date last modified: 2017-03-02