Mushrooms and Cancer: Evidence, Safety, Symptoms and Clinical Trials

Evidence checked October 24, 2026. Mushrooms appear in cancer discussions as foods, concentrated supplements, purified pharmaceutical preparations and psychedelic medicines. These are different interventions, with different evidence and risks.

The practical conclusion: some specific mushroom-derived products deserve serious research. No retail mushroom blend has established evidence that it cures cancer or can replace cancer treatment. The strongest historical cancer-outcome evidence concerns PSK used with older chemotherapy regimens; the clearest symptom-focused leads include reishi for fatigue and supervised psilocybin-assisted therapy for psychological distress. Neither establishes that an over-the-counter product will help an individual patient.

This review expands our concise mushroom evidence record. Read the guide to interpreting evidence and Integrative Care Guide for context. Educational information; discuss supplements and trial participation with your oncology team.

First, identify what is actually being studied

Category	Examples	What the evidence can tell us
Foods	Cooked shiitake, maitake, oyster and white-button mushrooms	Nutrition and dietary-pattern studies do not establish the efficacy of concentrated extracts. Mushrooms are optional foods, not an essential anticancer ingredient.
Nonpsychedelic supplements	Turkey tail, reishi, lion’s mane, chaga, cordyceps; powders, capsules, teas and tinctures	Species, strain, fungal part, substrate, extraction and dose can all differ. A shared name is insufficient to establish equivalence.
Defined mushroom-derived preparations	PSK, PSP, lentinan and proprietary AHCC	These are distinct preparations. PSK is not PSP; AHCC is not lentinan; a product standardized to total beta-glucans is not automatically any of them.
Psychedelic treatment	Measured psilocybin with preparation, monitored sessions and psychological support	This is a separate clinical and regulatory pathway. It does not validate “microdose” gummies or establish anticancer activity.

Fruiting body means the visible mushroom structure; mycelium is its network of filaments; spores are reproductive particles. Each can yield different constituents. “Fruiting body only” is not a universal marker of superior clinical evidence: PSK and AHCC have mycelial origins. The test is whether the final preparation matches the study. NCI overview; AHCC composition.

An evidence map by mushroom

Mushroom or preparation	Most relevant human evidence	Interpretation
Turkey tail — Trametes/Coriolus versicolor; PSK/PSP	Older adjunctive gastric/colorectal studies; small immune-marker studies	Product-specific historical signal; retail products and modern treatment combinations remain unproven.
Reishi — Ganoderma species	Small randomized fatigue study; current randomized breast-cancer symptom trial	Promising but preliminary for symptoms; no established survival benefit.
Shiitake — Lentinula edodes; lentinan	Older adjunctive studies, including a negative phase III gastric trial	Mixed evidence. Oral shiitake is not injectable lentinan.
AHCC — cultured shiitake-mycelial extract	Small HPV-clearance trial; oncology studies underway	HPV clearance is not proof of cancer prevention or treatment.
Maitake — Grifola frondosa	Small dose-escalation immune-marker study	Biological activity, with both stimulation and suppression; patient benefit unproven.
White button — Agaricus bisporus	Early prostate PSA and immune-marker results	Research lead; a PSA change is not proof of longer survival.
Agaricus blazei/subrufescens; AndoSan blends	Small randomized myeloma study	Immune changes without demonstrated clinical-outcome benefit.
Lion’s mane — Hericium erinaceus	Small cognitive studies outside oncology; extensive laboratory interest	No convincing human evidence identified for treating chemo brain, neuropathy or cancer.
Cordyceps species	Early combination studies registered in pancreatic cancer	No demonstrated benefit attributable to cordyceps alone.
Chaga — Inonotus obliquus	Laboratory claims; human kidney-injury reports	No established oncology benefit; concentrated use has meaningful safety concerns.
Psilocybin-containing mushrooms / purified psilocybin	Small randomized trials with psychological support in cancer-related distress	Promising supervised symptom treatment; separate from supplements and cancer control.

These judgments apply to the stated use and preparation. They are editorial summaries, not formal GRADE ratings. Key study details and primary-source links follow.

Turkey tail and PSK: real clinical history, limited transferability

A randomized Japanese study of 262 patients after gastric-cancer surgery compared older chemotherapy with or without PSK. Five-year survival was 73.0% versus 60.0%, and disease-free survival was 70.7% versus 59.4%. This was an adjunctive result with a defined preparation and regimen, not evidence for turkey-tail capsules purchased today. Read the original trial.

A 2022 Cochrane review included seven colorectal-cancer trials with 1,569 participants. It found low-certainty evidence of a small improvement in five-year survival, but very low-certainty evidence about chemotherapy adverse effects. The survival studies used regimens that do not reflect current preferred practice. This prevents a confident claim that PSK improves outcomes alongside today’s FOLFOX, CAPOX, targeted therapies or checkpoint inhibitors. Read the review.

A breast-cancer phase I study enrolled 11 women; nine completed treatment at 3, 6 or 9 g/day of a turkey-tail preparation for six weeks after radiotherapy. It assessed tolerability and immune markers, not recurrence or survival. A small safety study cannot establish universal safety or anticancer efficacy. Read the phase I study.

A current Mayo presurgical study is testing changes in Ki-67, a tumor-proliferation marker, in ER-positive/HER2-negative breast cancer. A change in Ki-67 would be a research signal, not proof that surgery can be omitted or that survival improves. NCT06450873.

Reishi: a symptom-care lead that still needs confirmation

In a randomized pilot involving 48 patients with breast cancer receiving endocrine therapy, four weeks of reishi spore powder improved reported fatigue and some quality-of-life measures compared with control. Its small size, short follow-up and specific formulation limit generalization. The absence of serious toxicity in this sample does not exclude uncommon harms. Read the pilot trial.

The ongoing Mayo randomized phase II study NCT06028022 evaluates reishi extract at 1,000 mg three times daily for four weeks, with a subsequent crossover period. Fatigue is the primary outcome; joint symptoms, quality of life and tolerability are also assessed. No registry results were posted at this review. Spore powder and an extract must not be assumed equivalent.

Claims that reishi broadly “boosts immunity,” prevents recurrence or helps every cancer symptom go beyond these data. Its role with immune-checkpoint inhibitors remains uncertain; immune stimulation is not automatically beneficial.

Shiitake and lentinan: include the negative phase III result

The randomized JFMC36-0701 trial assigned 309 patients with unresectable or recurrent gastric cancer to S-1 alone or S-1 plus lentinan. Median overall survival was 13.8 versus 9.9 months, respectively (P=0.208): no demonstrated survival benefit. Time to treatment failure was significantly shorter with lentinan, 2.6 versus 4.3 months. Quality of life did not improve. The numerically shorter survival should not be described as a statistically proven survival harm, but this trial clearly fails to support routine use in that setting. Read the phase III trial.

Purified lentinan administered within clinical treatment is not interchangeable with cooked shiitake, mushroom tea or an oral “shiitake complex.” Route and preparation matter as much as the species name.

AHCC: separate HPV findings from cancer claims

AHCC is a proprietary cultured-mycelial extract. In a randomized study of 50 women with persistent high-risk HPV, 41 completed the study. Fourteen of 22 evaluable AHCC recipients were HPV negative after six months; nine of those 14 maintained negativity six months after stopping. Two of 19 placebo recipients were negative at 12 months. These are small, completer-based results with different quoted time points, not a head-to-head cancer-prevention estimate. Read the full study.

The study did not establish fewer cervical cancers or treatment of an existing cancer. Vaccination when indicated, screening and management of abnormal cervical findings remain necessary. Current ovarian, head-and-neck and liver-cancer trials are listed below. AHCC also raises potential interaction concerns, particularly with aromatase inhibitors; see the safety section.

Maitake, Agaricus and white button: biomarkers need clinical follow-through

Maitake: a phase I/II study in 34 disease-free breast-cancer patients measured immune effects over three weeks. Some immune measures increased while others decreased; effects were not simply greater at higher doses. Two participants withdrew with possibly related mild adverse effects. This is a useful corrective to the phrase “immune booster,” not proof of fewer infections or recurrences. Read the study.

Agaricus/AndoSan: a randomized study of 40 patients undergoing myeloma transplantation found immune-marker changes but no statistically significant differences in treatment response, overall survival or time to new treatment. The mixture’s results cannot be assigned to one ingredient. Read the trial.

White button: a phase I study treated 36 men with biochemical prostate-cancer recurrence. Four had protocol-defined PSA responses; 13 had some PSA decline at three months. There was no randomized control group. PSA responses do not establish tumor eradication or survival benefit. Read the phase I study.

Later translational work found changes in suppressive immune cells in patients and antitumor effects in mice. The checkpoint-inhibitor combination findings came from mice; human immune-marker results do not establish that adding mushroom tablets improves immunotherapy. Read the translational paper.

Lion’s mane, cordyceps, chaga and other popular products

Lion’s mane: cognitive findings in people without cancer cannot be transferred to chemotherapy-related cognitive impairment. No convincing clinical oncology evidence was identified for neuropathy, chemo brain, tumor response or survival. A plausible nerve-growth mechanism is a reason to study it, not a reason to promise nerve repair. Evidence overview.

Cordyceps: two pancreatic-cancer studies combine it with reishi and vitamin C. These uncontrolled combination studies cannot isolate a cordyceps effect, and no results were posted in the reviewed records. Their registry phase labels do not turn them into confirmatory randomized trials. NCT06601283; NCT06598033.

Chaga: laboratory anticancer findings have not established clinical cancer benefits. Case reports describe oxalate-associated kidney injury, including irreversible kidney failure. This makes concentrated chaga a poor choice for an oncology supplement, especially with kidney disease or stone risk. Safety review and case references.

Tremella, Phellinus, Antrodia and mixed “functional mushroom” coffees also appear in wellness marketing. This review did not establish a reproducible patient-centered oncology benefit for them. A blend with more species does not have stronger evidence unless that exact blend has been tested.

What about cancer symptoms, topical products and survivorship?

Goal	What the evidence currently supports
Fatigue	Preliminary reishi data; further randomized results needed. Evaluate treatable causes of fatigue and continue established supportive care.
Aromatase-inhibitor joint pain	Reishi is being tested. Efficacy has not yet been established.
Nausea, appetite loss and weight loss	No convincing mushroom-specific clinical benefit identified. These products should not replace antiemetics or nutrition care.
Neuropathy or chemo brain	No established mushroom treatment; lion’s-mane marketing exceeds oncology data.
Anxiety, depression and existential distress	Psilocybin-assisted treatment has promising small trials in screened patients with structured support. Routine unsupervised use is not supported.
Cancer pain	Psilocybin feasibility studies are underway; mushrooms are not established analgesics.
Sleep	No well-established mushroom-specific oncology sleep treatment identified. Improvements in another symptom do not prove a direct insomnia benefit.
Radiation skin reactions / topicals	A small randomized cosmetic-formulation study is registered, but no registry results were posted. No established efficacy for radiation dermatitis, drug rash, alopecia or topical cancer treatment was identified.
Infections, low white counts or treatment tolerance	Immune-marker changes are not proof of fewer infections or preserved chemotherapy dosing. Evidence is insufficient for routine substitution of standard supportive measures.
Recurrence prevention and longer survival	Historical PSK results are setting-specific. No general claim is justified for commercial mushroom supplements.

The topical breast-radiotherapy study NCT07755553 enrolled 50 participants and assessed skin hydration and other skin measures. It was first posted after the study began, which limits confidence in prospective outcome specification. Registration alone does not establish benefit. Any product applied to irradiated or damaged skin should be reviewed by the radiation team.

Mushrooms as food: association is not prevention

Observational studies are mixed. A pooled analysis reported lower cancer risk among higher mushroom consumers, but it cannot separate mushrooms from other dietary and lifestyle differences. In two large US prospective cohorts, higher intake was not associated with lower total cancer risk. These findings do not establish a cancer-prevention dose. Observational meta-analysis; US cohort study.

People who enjoy mushrooms can use ordinary edible varieties as part of their food pattern, following their clinical team’s food-safety advice. People who dislike them do not need to eat them or take a supplement. Food choices should remain compatible with nutritional needs, allergies and personal preferences.

Safety: distinguish observed harms from theoretical interactions

Issue	What is known and how to interpret it
Liver injury	Reports exist with reishi and Agaricus products. Rare case reports cannot establish incidence, and formulations/co-exposures vary; they still warrant caution. Reishi; Agaricus case series.
Kidney injury	Chaga-associated oxalate nephropathy is documented in case reports. Risk is particularly concerning with concentrated powders and renal vulnerability. Source.
Bleeding and perioperative use	Reishi may increase bleeding risk. Anticoagulants, antiplatelets, thrombocytopenia and procedures require individual review. The current reishi trial excludes several of these situations. Source.
Drug metabolism	Reishi enzyme effects are largely laboratory observations; clinical magnitude is uncertain. Review the exact product with an oncology pharmacist, especially with oral anticancer drugs. Source.
AHCC and endocrine/other therapy	Preclinical aromatase and CYP2D6 effects raise possible interactions with aromatase inhibitors and other drugs. Clinical significance is not established; absence of human proof is not reassurance. Source.
Immunotherapy, autoimmune disease and transplantation	Immune modulation can be complex. Neither efficacy nor compatibility with checkpoint inhibitors, immunosuppressants or transplantation can be presumed. Trial supervision matters.
Allergy, GI effects and contaminants	Rashes and gastrointestinal effects occur. Species substitution, residual growing substrate and contamination can complicate interpretation. A product’s identity and testing matter.
Tumor-marker interpretation	Reishi spore powder has been associated with elevated CA72-4. Tell the oncology team about use before interpreting an unexpected marker change. Source.

Provide the care team with the bottle label, brand, batch, ingredient amounts and start date. Stop the product and seek medical advice for jaundice, dark urine, reduced urine, unusual bleeding or a significant rash; urgent assessment is appropriate for breathing difficulty or swelling. Do not independently stop cancer therapy or prescribed psychiatric medicines.

Studied doses are descriptions, not prescriptions

Preparation / context	Dose used in a study	Why it cannot be generalized
PSK in historical gastric studies	3 g/day in specified regimens; schedules varied	This is a defined preparation used alongside chemotherapy, not a turkey-tail retail equivalent. Source.
Turkey-tail phase I after breast radiotherapy	3, 6 or 9 g/day for six weeks	Small tolerability study, not an efficacy dose-finding study. Source.
Reishi in the current Mayo fatigue study	1,000 mg extract three times daily for four weeks before crossover	Investigational dose and formulation; not evidence that any 3-g reishi product is effective. NCT06028022.
AHCC for persistent HPV	3 g once daily for six months in the randomized arm	Applies to a proprietary formulation and a noncancer endpoint. Source.
White-button prostate phase I	Responses reported at 8–14 g/day across responding patients	An uncontrolled early study does not define an effective cancer-treatment dose. Source.
Psilocybin-assisted clinical research	Some current protocols use a measured 25-mg pharmaceutical dose	Given with screening and supervision; never convert this into grams of wild mushrooms or gummies. NCT05398484.

There is no reliable cross-product conversion from an “extract ratio,” total polysaccharide percentage or number of gummies to a clinically validated dose. Tea, tincture, powder, spore product and extract should not be substituted on a milligram-for-milligram basis.

Psilocybin and cancer: a separate clinical question

Two 2016 randomized crossover studies enrolled 51 and 29 patients with cancer-related psychological distress. Both reported substantial improvements in anxiety and depression with psilocybin in a structured supportive setting. Benefits persisted in follow-up, but small selected samples, difficult blinding, expectancy effects and crossover designs limit conclusions. These were psychological outcomes, not tumor-response or survival studies. Johns Hopkins trial; NYU trial.

Care involves psychiatric and medical screening, preparation, a monitored session and follow-up support. Risks include acute fear, confusion, nausea and cardiovascular changes; vulnerability to mania or psychosis requires careful assessment. Drug interactions and medication changes belong with the treating clinicians. The safety and efficacy of microdosing are not established. NCCIH overview.

Access and legality, checked October 24, 2026: psilocybin remains federally Schedule I in the United States. Oregon and Colorado have state-regulated service pathways, but these do not create nationwide retail legality or establish FDA approval for cancer-related distress. For a patient with cancer, a registered clinical trial offers a defined protocol and medical oversight. Check current local rules and the program’s medical capabilities. Federal status; Oregon services; Colorado framework.

Amanita muscaria and muscimol products are different from psilocybin. FDA determined that Amanita and specified constituents are unapproved additives for conventional foods and do not meet the GRAS safety standard. “Legal mushroom gummy” is not a clinical evidence category. FDA notice.

Clinical trials: a dated directory, not an endorsement

The records below were checked directly through ClinicalTrials.gov on October 24, 2026. Status is sponsor-reported, and an old “recruiting” entry may not mean a site is accepting participants today. Confirm with the listed study team. No summary results were posted in these selected records at the time of review; this does not rule out journal publications or conference reports. Enrollment numbers marked planned are targets, not completed samples.

Study	Design / sample	Registry status	How to interpret it
NCT06028022 Reishi; breast cancer on aromatase inhibitors	Mayo; randomized crossover phase II; planned 80	Recruiting Updated 2026-10-16	Fatigue primary; joint symptoms secondary. Best symptom-focused mushroom trial to follow.
NCT06450873 Turkey tail; presurgical ER+/HER2− breast cancer	Mayo; single-arm phase II; planned 40	Recruiting Updated 2026-10-16	Ki-67 change. Not evidence to delay surgery or substitute for endocrine therapy.
NCT04913064 White button; high breast-cancer risk	City of Hope; single-arm; planned 26	Recruiting Updated 2026-01-05	Immune/inflammation biomarkers, not demonstrated cancer prevention.
NCT06693323 AHCC; HPV-positive head-and-neck cancer	UC Irvine; single-arm phase II; planned 34	Recruiting Updated 2025-03-27	Adjunct to standard care; no randomized efficacy conclusion available.
NCT05763199 AHCC; ovarian adjuvant chemotherapy	UC Davis; randomized feasibility pilot; planned 20	Active not recruiting Updated 2026-03-12	Primary questions include feasibility and adherence.
NCT07118735 AHCC; liver cancer receiving immunotherapy	National Cheng-Kung University Hospital; randomized; planned 94	Not yet recruiting Updated 2025-08-12	Objective response endpoint. Old status requires site confirmation.
NCT06601283 Cordyceps + reishi + vitamin C; pancreatic chemotherapy	Fudan; uncontrolled combination study; planned 50	Recruiting Updated 2024-11-26	Anemia endpoint; no single-ingredient attribution. Last update is old.
NCT06598033 Cordyceps + reishi + vitamin C; advanced pancreatic cancer	Fudan; uncontrolled combination study; planned 50	Recruiting Updated 2024-11-26	Quality-of-life endpoint; no efficacy conclusion. Last update is old.
NCT04519879 White button; prostate cancer	City of Hope; phase II; actual 133	Suspended Updated 2026-08-10	Suspended. Registry cites delinquent PMT reporting; this is not a demonstrated toxicity finding.
NCT06323473 Maitake; integrative cancer care	Canadian College of Naturopathic Medicine; single-arm; actual 20	Completed Updated 2026-10-09	Completed; immune-count endpoint; await results.
NCT07524777 Reishi spores; depression after thyroid-cancer surgery	Randomized placebo-controlled; actual 300	Completed Updated 2026-08-28	Completed; registered sample size is not evidence of a positive result.
NCT07755553 Topical mushroom formulation; breast radiotherapy	Hifas da Terra; randomized cosmetic study; actual 50	Completed Updated 2026-10-13	Skin hydration primary; retrospectively registered relative to study start.
NCT06599710 AndoSan; colorectal-cancer fatigue	Withdrawn; actual enrollment 0	Withdrawn Updated 2026-07-09	Insufficient recruitment. Provides no patient efficacy data.
NCT05398484 Psilocybin-assisted therapy; advanced-cancer distress	NYU; randomized; planned 200	Recruiting Updated 2026-10-14	Anxiety, depression and existential-distress research.
NCT06319378 Psilocybin; cancer-related major depression	Northern Stockholm Psychiatry; randomized; planned 100	Recruiting Updated 2026-04-13	25 mg versus 1 mg under a clinical protocol.
NCT06001749 Psilocybin; advanced-cancer pain	Single-arm pilot; planned 15	Recruiting Updated 2026-08-05	Feasibility and acceptability primary; not established analgesic efficacy.
NCT06827054 Psilocybin + psychotherapy; chronic cancer pain	Single-arm study; planned 20	Not yet recruiting Updated 2026-08-12	Not yet recruiting; investigational pain treatment.

To explore further: mushroom and cancer search or psilocybin and cancer search. Eligibility, geography, treatment timing and the exact preparation determine whether a study is relevant.

Choosing a product: the questions matter more than the brand

What precise goal is being treated, and has that outcome improved in a controlled human study?
Does the label identify the Latin species, fungal part, extraction method and amount per daily serving?
Is this the actual studied preparation? A “PSK-like” or “clinical strength” label does not establish equivalence.
Is there a batch-specific certificate of analysis from a competent independent laboratory for identity, measured constituents, heavy metals and microbial contamination, with relevant pesticide/solvent testing?
Does testing distinguish beta-glucans from alpha-glucans/starch where relevant? “Total polysaccharides” alone is not enough to characterize a product.
What are the potential interactions with the full medication list, and who will monitor adverse effects?
If animal-free sourcing matters, are capsule shells, excipients, growing media and processing aids verified? Some cordyceps production uses insects; do not assume all products are vegan.
What is the total monthly cost at the studied dose, and what patient-important benefit would make that cost worthwhile?

US dietary supplements are regulated, but FDA does not preapprove them for safety and effectiveness as it does drugs. Independent quality testing can improve confidence in identity and purity; it does not prove a cancer benefit. Supplements sold with cancer-treatment claims require particular scrutiny. FDA guidance.

The conclusion for patients

A promising mechanism is the beginning of a research story. For an individual with cancer, the useful questions are narrower: Which preparation? For which symptom or cancer setting? At what dose? Compared with what? With what risk? Defined clinical trials can answer these questions; a broad “immune support” promise cannot.

Mushrooms should not replace cancer therapy, antiemetics, infection management, nutrition support or mental-health care. If you want to explore a product, start with its exact formulation and a pharmacist or oncologist review. If you want to explore psilocybin, begin with a legitimate research or regulated clinical-service pathway and appropriate screening.

Methods and editorial independence

This is a structured narrative review of primary clinical papers, NCI and NCCIH summaries, oncology-center safety resources, current official regulatory sources and selected ClinicalTrials.gov records. It is not an exhaustive systematic review. Laboratory, animal, observational, randomized and registry-only findings are distinguished throughout. Trial registration demonstrates a question being studied, not a positive finding.

Disclosure: the author is developing an oncology supportive-care company. This article evaluates the evidence independently and does not recommend or promote a company product.