What the studies report, and how much of it there is.

What the literature looks like

Human evidence on lion's mane is small. This library holds 10 human trials, all of them short and small: the largest has 77 participants and the others with a known size have 10 to 41. Durations range from a single dose to 49 weeks, and only two ran longer than 12 weeks. No meta-analysis of lion's mane trials was found, and the two systematic reviews included here report mixed results and call for larger studies. Several trials were run or co-authored by people tied to the product maker, and the tested materials differ (fruiting body, erinacine A mycelium, mixed biomass, extracts), so results cannot be pooled or transferred to a gummy. The mechanism work is mostly cell and rodent research, and one cell study found that hericenones were not the NGF-inducing compounds. Erinacines are reported in mycelium and not detected in fruiting body, so the two materials are not interchangeable. Rat toxicity studies show no toxicity at high doses, while human safety data is limited to short trials and a few case reports.

Safety. Rat studies of lion's mane powder, extract and erinacine A mycelium found no toxicity at high doses. Rare case reports exist: one of acute respiratory distress syndrome with lymphocyte reactivity to an extract, and one of occupational contact dermatitis from handling the fresh mushroom. A systematic review lists stomach discomfort, headache and allergic reactions as possible, commonly unreported effects. People with mushroom allergy should avoid it, and nothing here establishes safety in pregnancy or with medication.

What the literature looks like

The human evidence on Cordyceps is small, short and mixed. Across the verified trials, most enrolled between 12 and 80 people and ran from a single dose to 16 weeks. Several C. militaris trials report higher natural killer cell activity or some immune markers, but those are laboratory markers in healthy adults, not fewer infections. For exercise, results conflict: a 2004 trial of a cultured O. sinensis-type product found no change in cyclists, a 2010 pilot found threshold changes but no VO2 max change, and a 2025 meta-analysis reports borderline pooled benefits (p values 0.03 to 0.05). The 2025 Current Nutrition Reports review and the 2026 Nutrients narrative review both call the findings inconsistent and cite small samples, multi-ingredient products and unstandardized preparations. Many trials used mycelium, fermented or blended products, so results do not transfer cleanly to a C. militaris fruiting body gummy. Cordycepin is rapidly broken down in the body in preclinical work, and doses in trials are not standardized. Safety data are reassuring in short trials and rat studies but sparse for long-term use, and one case report links daily C. sinensis use to prolonged post-surgical bleeding.

Safety. Long-term and interaction data are lacking. One case report links daily C. sinensis use to prolonged bleeding after dental surgery, so a general advice to tell clinicians about supplements before surgery and to consult a doctor if on blood thinners, immunosuppressants or with autoimmune conditions is prudent (this is precaution, not an established interaction). Wild O. sinensis can carry arsenic and heavy metals, and the market has authenticity problems, which argues for batch contaminant and identity testing of any product.

What the literature looks like

Background papers on mushroom beta-glucans, how mushroom products differ by part and growing method, and quality and reaction reports. Most entries are reviews or lab analyses, not trials of finished products.