Human Clinical Studies on Medicinal Mushrooms: What Exists, Limits and Conflicts
What human clinical trials of medicinal mushrooms exist, where results conflict, who paid for some of them, and why small, short trials of different products limit what can be concluded.
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.
Short answer. There are human trials of medicinal mushrooms, but few per mushroom, and they are small, short and use different products. Their results often disagree. They cannot tell a reader which product to buy, and they are not a reason to change any treatment.
Safety first. Ingredients in mushroom supplements may vary from lot to lot, and the US National Cancer Institute (NCI) notes there is no guarantee that label ingredients are present. [1] A trial's result belongs to the exact product tested. If you take medicines or have cancer, kidney or liver disease, ask a pharmacist or clinician first. See mushroom supplements and medicines.
What counts as a clinical study
Clinical trials are done with people and give the clearest information about whether a treatment is effective and safe in humans. [2] In a double-blind trial, neither participants nor researchers know who gets the treatment. [3] Small studies are more likely to produce results due to chance. [4]How much exists
In a PubMed search on 2026-10-23, records tagged as randomized controlled trials numbered 5 for lion's mane names, 28 for reishi names, 32 for Cordyceps names, 21 for turkey tail names, 35 for shiitake names and 0 for chaga names. [5] We did not screen each record, so some are formulas with several ingredients. Counts for every mushroom are on research by mushroom. A 2025 systematic review of lion's mane found five randomized trials and three pilot trials, mostly of cognition. [6]Where results conflict
| Topic | One finding | Another finding | What it means |
|---|---|---|---|
| Cordyceps and exercise | 22 trained cyclists, 5 weeks: no change in endurance [7] | 20 healthy older adults, 12 weeks: higher exercise thresholds [8]; a 2025 pooled analysis reported improved endurance, p = 0.05 [9] | Different people and products; pooled result sits at the usual cut-off |
| Reishi, blood sugar and lipids | Cochrane review and an 84-person trial: no benefit [10][11] | A 110-person trial of reishi spore oil reported lower cholesterol and triglycerides [12] | Spore oil is a different product from powder; do not transfer |
| Lion's mane and thinking | Older adults with mild impairment: higher scores, which fell after stopping [13] | Healthy young adults: one faster attention test, with the authors noting null findings too [14] | Result depends on the group studied; the effect did not last |
| Maitake | One strain raised a cognition score [15] | The other strain, same bread format, did not [15] | The strain mattered |
| Cancer add-ons (PSK, lentinan) | NCI summary: PSK studies in colorectal cancer showed less recurrence and better survival [1] | Cochrane 2022: low-certainty small survival effect [16]; lentinan trial: survival did not improve [17] | Strength varies by product, cancer and era of chemotherapy |
| Snow fungus species | Tremella fuciformis (GBIF-accepted name): better memory-complaint scores [18] | Tremella mesenterica for Helicobacter pylori: one patient cleared infection versus 70% on standard therapy [19] | Different species and outcomes cannot be combined |
A trial of reishi spore powder for Alzheimer disease (42 people, 6 weeks) found no better results than placebo on the main scale. [20]
Who paid
Funding does not make a study wrong, but it is worth knowing.| Study | What the paper says |
|---|---|
| Lion's mane, young adults | The supplier provided the product only and had no role in design or analysis [14] |
| Lion's mane and a tea extract | Funded in part by a food-ingredient company; one author reports supplement-company funding [21] |
| Mushroom blend for stress, fatigue and sleep | Funded by the company that also supplied the product [22] |
| Cordyceps militaris drink | Funded by a Thai national innovation agency; no competing interests [23] |
| Reishi spore powder, Alzheimer disease | University project grant; no conflicts declared [20] |
Frequently asked questions
How many human trials of medicinal mushrooms exist?
It varies by mushroom, from none tagged for chaga to dozens for others in one PubMed search. [5]
Why do mushroom studies disagree?
They use different species, parts, forms, amounts, people and outcomes. Strain mattered in one maitake trial. [15]
Does industry funding invalidate a trial?
No, but it matters when judging one. Some papers state who funded them. [22]
Are small trials useless?
No. They can suggest ideas but are more likely to show chance results. [4]
Can a trial of one product apply to another?
Not safely. A reishi spore oil result is not a result for reishi powder. [12][10]
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.
Limits and uncertainty
- Sizes were small: 15 per group in the lion's mane cognition trial [13], 20 in a Cordyceps pilot [8].
- Reishi trials in one meta-analysis ran 1 to 24 weeks; certainty was very low for all outcomes. [24]
- Blood markers are not health outcomes, and results for one species or form do not carry over to another.
- Long-term safety is poorly studied. A lion's mane review lists stomach discomfort, headache and allergic reactions as possible, if commonly unreported. [6]
- Reports exist of shiitake dermatitis, mostly after raw mushrooms. [25]
Related pages: mushroom research limitations and the research overview.
References
- National Cancer Institute. Medicinal Mushrooms (PDQ), health professional version. Updated 2024-11-06. Read 2026-10-23.
- National Center for Complementary and Integrative Health. Know the Science: Types of Research. Read 2026-10-23.
- National Center for Complementary and Integrative Health. Know the Science: Design of the Study. Read 2026-10-23.
- National Center for Complementary and Integrative Health. Know the Science: Size of the Study. Read 2026-10-23.
- National Library of Medicine. PubMed, searched through NCBI E-utilities (esearch) on 2026-10-23. Each mushroom was searched by scientific and common names in the title or abstract, filtered by publication type (randomized controlled trial; systematic review or meta-analysis) or by the Humans and Animals MeSH tags, for records up to 2026-10-23. The goal snapshot combined a fixed list of medicinal mushroom names with goal words. Counts change as records are added. Read 2026-10-23.
- Benefits, side effects, and uses of Hericium erinaceus as a supplement: a systematic review. Front Nutr. 2025. PubMed 40959699. Read 2026-10-23.
- Cordyceps Sinensis (CordyMax Cs-4) supplementation does not improve endurance exercise performance. Int J Sport Nutr Exerc Metab. 2004. PubMed 15118196. Read 2026-10-23.
- Effect of Cs-4 (Cordyceps sinensis) on exercise performance in healthy older subjects: a double-blind, placebo-controlled trial. J Altern Complement Med. 2010. PubMed 20804368. Read 2026-10-23.
- Effects of fungal supplementation on endurance, immune function, and hematological profiles in adult athletes: a systematic review and meta-analysis. Front Nutr. 2025. PubMed 41280379. Read 2026-10-23.
- Ganoderma lucidum mushroom for the treatment of cardiovascular risk factors. Cochrane Database Syst Rev. 2015. PubMed 25686270. Read 2026-10-23.
- A double-blind, randomised, placebo-controlled trial of Ganoderma lucidum for the treatment of cardiovascular risk factors of metabolic syndrome. Sci Rep. 2016. PubMed 27511742. Read 2026-10-23.
- Clinical Evaluation of Ganoderma lucidum Spore Oil for Triglyceride Reduction: A Randomized, Double-Blind, Crossover Study. Nutrients. 2025. PubMed 40077714. Read 2026-10-23.
- Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial. Phytother Res. 2009. PubMed 18844328. Read 2026-10-23.
- The Acute and Chronic Effects of Lion's Mane Mushroom Supplementation on Cognitive Function, Stress and Mood in Young Adults: A Double-Blind, Parallel Groups, Pilot Study. Nutrients. 2023. PubMed 38004235 (full text via Europe PMC PMC10675414). Read 2026-10-23.
- Maitake Mushroom (Grifola frondosa) Enhances Cognitive Function in Healthy Older Japanese: A Randomized, Double-Blind, Placebo-Controlled Trial. J Nutr Sci Vitaminol. 2026. PubMed 42055721. Read 2026-10-23.
- Coriolus (Trametes) versicolor mushroom to reduce adverse effects from chemotherapy or radiotherapy in people with colorectal cancer. Cochrane Database Syst Rev. 2022. PubMed 36445793. Read 2026-10-23.
- Randomised phase III study of S-1 alone versus S-1 plus lentinan for unresectable or recurrent gastric cancer (JFMC36-0701). Eur J Cancer. 2016. PubMed 27501505. Read 2026-10-23.
- Efficacy and Safety of Tremella fuciformis in Individuals with Subjective Cognitive Impairment: A Randomized Controlled Trial. J Med Food. 2018. PubMed 29319408. Read 2026-10-23.
- Yellow brain culinary-medicinal mushroom, Tremella mesenterica Ritz.:Fr. (higher Basidiomycetes), is subjectively but not objectively effective for eradication of Helicobacter pylori: a prospective controlled trial. Int J Med Mushrooms. 2012. PubMed 22339708. Read 2026-10-23.
- Spore powder of Ganoderma lucidum for the treatment of Alzheimer disease: A pilot study. Medicine (Baltimore). 2018. PubMed 29742702 (full text via Europe PMC). Read 2026-10-23.
- Acute Effects of Naturally Occurring Guayusa Tea and Nordic Lion's Mane Extracts on Cognitive Performance. Nutrients. 2023. PubMed 38140277 (full text via Europe PMC PMC10745489). Read 2026-10-23.
- Adaptogenic Effects of Mushroom Blend Supplementation on Stress, Fatigue, and Sleep: A Randomised, Double-Blind, and Placebo-Controlled Trial. Brain Behav. 2026. PubMed 41540766 (full text via Europe PMC PMC12808922). Read 2026-10-23.
- A randomized controlled clinical trial examining the effects of Cordyceps militaris beverage on the immune response in healthy adults. Sci Rep. 2024. PubMed 38580687 (full text via Europe PMC PMC10997757). Read 2026-10-23.
- The Nutritional Significance of Ganoderma lucidum on Human Health: A GRADE-Assessed Systematic Review and Meta-Analysis of Clinical Trials. Food Sci Nutr. 2025. PubMed 40510787. Read 2026-10-23.
- Clinical features of shiitake dermatitis: a systematic review. Int J Dermatol. 2017. PubMed 28054338. Read 2026-10-23.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.