Mushrooms and Cancer: Claims Checked, What Is Known and Why Care Teams Must Know
Claims that mushrooms fight cancer, checked against the National Cancer Institute, Cochrane reviews and other sources, with why your cancer care team needs to know about every product.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
Start here: tell your cancer care team
Mushroom products are not a treatment for cancer and should never replace the care your oncology team recommends. The National Center for Complementary and Integrative Health (NCCIH, US) says no complementary approach has been shown to cure cancer or cause it to go into remission, and that some may interfere with conventional treatment. [1] It advises anyone with cancer to consult their health care provider before adding any complementary health product. [1] It also notes that some herbs may make chemotherapy drugs less effective and that herbal supplements may interact in harmful ways with drugs, including cancer drugs. [1] That is why every mushroom product, tea, powder or capsule belongs on the list you give your oncology team and pharmacist. See what to tell your care team and talking with a health professional.The claims as marketed
You will see statements such as "turkey tail fights cancer", "reishi supports immunity during chemo" or "mushrooms shrink tumors". This page checks what sources say about those ideas. It describes research. It does not tell any reader to use, stop or change a treatment.Traditional use (not evidence)
NCI notes that turkey tail (called Yun Zhi in traditional Chinese medicine) has been used in that tradition for lung diseases, and that reishi has been used as medicine in East Asia for a very long time. [3] That describes tradition. It is not proof that either treats cancer.What research shows
| Question | What the source found | Strength of evidence | Form and group studied |
|---|---|---|---|
| PSK with chemotherapy for stomach cancer | NCI reports a review of 8 randomized trials in 8,009 patients that suggested people given chemotherapy plus PSK lived longer after surgery. [3] | Promising but limited; includes older Japanese trials, reported here through NCI's summary | PSK extract (a medicine in Japan), people who had surgery for gastric cancer |
| PSK for breast cancer | Studies have focused on immune-system measures rather than patient survival or quality of life. [3] | Insufficient evidence for clinical outcomes | PSK |
| Turkey tail extract during colorectal cancer treatment (Cochrane review) | Seven randomized trials, 1,569 people. Low-certainty evidence of a small improvement in five-year survival; very low certainty on side effects, and unclear whether side effects came from chemotherapy or the extract. [6] | Low to very low certainty | Extract in all seven trials (mostly PSK), added to chemotherapy or radiotherapy |
| Reishi for cancer (Cochrane review) | Five randomized trials; the review did not find sufficient evidence to justify reishi as a first-line cancer treatment, rated trial quality "unsatisfying", and said it was uncertain whether reishi prolongs survival. [7] The same review said reishi might be considered an add-on to conventional treatment because of its potential to stimulate immunity, but that its extract should be used judiciously. [7] | Insufficient evidence | Reishi products in the trials; reporting was inadequate |
| Injectable lentinan with chemotherapy for stomach cancer | A review of 31 randomized trials (2,729 patients) reported better treatment response with lentinan plus chemotherapy than chemotherapy alone, and said more trials were needed. [8] | Promising but limited; trials are of an injectable medicine, not a supplement | Lentinan injection (a beta-glucan; see shiitake and lentinan research) |
| All mushroom supplements in cancer care (systematic review) | Of 39 clinical studies from 2010 to 2020, many were small or not randomized; the review judged the evidence inconclusive for routine use. [9] It reported a survival benefit with Huaier granules (a different fungus, Trametes robiniophila) in some studies. [9] | Insufficient evidence | 12 different mushroom preparations across 39 studies |
| Eating mushrooms and breast cancer risk | A pooled analysis of observational studies suggested an inverse association; the authors say it needs confirmation in larger prospective studies. [10] | Observational only; cannot show cause | Mushrooms eaten as food; 8 case-control and 2 cohort studies |
Laboratory and animal work: NCI describes lab and animal studies of PSK on the immune system and of reishi's active ingredients on tumors. [3] Those are preclinical (cells or animals) and do not tell us what happens in a person.
What a reader can safely do
- Tell your oncology team and pharmacist about every product, with the label or a photo of it.
- Ask whether the product could interact with your treatment, and whether to wait until after treatment.
- Do not stop, skip or change a prescribed treatment because of a supplement; ask the prescriber.
- Be wary of anyone selling a mushroom as a cure. NCCIH advises talking to your provider before using any anticancer product you have seen advertised. [1]
For product-specific research, see turkey tail, PSK and cancer care, PSK, PSP and lentinan and, for traditional Chinese medicine in cancer care, TCM and cancer: supportive care.
Frequently asked questions
Do mushrooms cure cancer?
No source we read says so. NCCIH states that no complementary approach has been shown to cure cancer or cause it to go into remission. [1]
Does turkey tail help during chemotherapy?
A Cochrane review found low-certainty evidence of a small survival difference at five years in colorectal cancer trials, and very low certainty about side effects. [6] Talk to your oncology team first.
Is PSK the same as a turkey tail supplement?
No. PSK is a purified extract that is an approved product used for cancer treatment in Japan. [3] NCI says supplement batches and brands may differ. [3]
Is reishi proven against cancer?
A Cochrane review did not find sufficient evidence to justify reishi as a first-line cancer treatment. [7]
Should I tell my doctor if I take mushroom supplements?
Yes. NCCIH advises people with cancer to consult their health care providers before using any complementary health approach. [1]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Two things are often confused: approved mushroom medicines vs supplements
- PSK (also called krestin) is a purified hot-water extract from the cultivated mycelium of turkey tail, Trametes versicolor, used in Japan as an add-on cancer treatment. [2] The National Cancer Institute (NCI, US) says PSK is an approved mushroom product used to treat cancer in Japan, and that medicinal mushrooms have been approved as an addition to standard cancer treatments in Japan and China for more than 30 years. [3]
- In the US, NCI states the FDA has not approved turkey tail or PSK, or reishi, as a treatment for cancer or any other medical condition. [3] NCI adds that the FDA does not regularly review how supplements are made, so batches and brands of mushroom supplements may not be the same. [3]
So a Japanese prescription extract studied in trials is not the same thing as a turkey tail capsule, powder or tea on a shelf. Results for one do not transfer to the other. Scientific names follow GBIF: Trametes versicolor (synonym Coriolus versicolor) [4] and reishi, Ganoderma lucidum. [5]
Risks and what the sources say
- Side effects in studies: in the systematic review, most reported adverse effects were grade 2 or lower, mainly nausea, vomiting, diarrhea and muscle pain. [9] In the reishi Cochrane review, no major toxicity was reported in the trials. [7]
- Not enough to rule out harm: small, short trials cannot find rare problems. The colorectal review could not tell whether side effects came from chemotherapy or the extract. [6]
- Interactions: the sources we read for this page do not list a specific interaction for turkey tail or reishi with a named chemotherapy drug. That is not proof there is none; NCCIH's general warning above applies. For the reishi liver, bleeding and blood-pressure cautions, see reishi side effects and liver injury reports.
- Immune-active products may matter for people with autoimmune conditions or transplants; see mushrooms, autoimmune conditions and transplants.
- Surgery: tell the surgical team about every supplement; see mushrooms, surgery and bleeding.
- Quality: supplement batches may differ, as NCI notes. [3] See quality testing and certifications.