The short answer. There isn't much data on Shiitake yet — 9 mentions, 0 with a clear outcome — so treat these numbers as anecdotal. There is a moderate body of research — 4 meta-analyses and 9 trials.
From 9 mentions in total — the rest didn't say how it went and aren't counted.
Of the people who reported each effect, the share who said it got better.
Systematic reviews and meta-analyses from PubMed, with their published conclusions.
At least one meta-analysis, or 5+ randomized controlled trials. The grade measures how much human research exists — read the conclusions below for what it found.
Conclusion: Based on the included case reports, it appears that medical treatment may slightly shorten the course of disease (to 9-11 d, varying by therapy) but should be considered on an individual patient basis. However, the treatment of symptoms, reassurance, and the avoidance of re-exposure are sufficient treatment recommendations for this condition.
PubMed 28054338 ↗Conclusion: Additionally, no differences were found in AEs or QoL. Overall, the evidence does not support clear recommendations, and more high-quality, well-designed randomized trials are needed.
PubMed 42648714 ↗Conclusion: It is possible that daily recommendations for B12 can be met by a varied diet containing non-animal B12 food sources. Future research should consider different methods of storage, preparation, fermented foods and standardization of the production of certain foods.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2022.2053057.
PubMed 35343314 ↗Conclusion: The 9474 reported lentinan-associated cancer treatment cases include lung cancer (3469 cases), gastric cancer (3039 cases), colorectal cancer (1646 cases), ovarian cancer (183 cases), cervical cancer (130 cases), Non-Hodgkin lymphoma (70 cases), pancreatic cancer (15 cases), cardiac cancer (15 cases), nasopharyngeal cancer (14 cases), duodenal cancer (1 case) and 110 cancer cases with no classifying patient information. Overall clinical data show solid effect of lentinan on improving the quality of life and on promoting the efficacy of chemotherapy and radiation therapy during cancer treatment
PubMed 31030752 ↗As stated by users — not a recommendation. Follow the label or your doctor.
How often each side effect came up across all reports.
First-hand experiences, quoted verbatim. We show one positive and one negative where both exist.
“I find eating 100g fried with some onions to give me a mental boost”
User data from public discussions; research from PubMed. Information only, not medical advice — talk to a doctor before starting, stopping or combining anything. Data updated October 3, 2026. How we rate