Lin C.-C., Chen C.-H., Lin T.-Y., Yang W.-C., Huang Y.-L. Immunomodulatory and anti-fatigue effects of a standardized Ganoderma lucidum water extract in healthy adults: A randomized, double-blind, placebo-controlled trial. Journal of Ethnopharmacology. 2023;315:116287.
Rationale
Reishi's immunity claims needed a modern double-blind test with functional immune assays plus the symptom domains (fatigue, sleep) for which people actually take it.
Methods
A randomized double-blind placebo-controlled parallel-group trial: 84 healthy adults took 3 g/day of standardized reishi water extract or placebo for 12 weeks, measuring NK-cell count and activity, cytokines (IL-2, IFN-γ), the FSS fatigue scale and PSQI sleep quality.
Results
NK-cell count and activity rose significantly — +34% and +42% versus placebo — with IL-2 and IFN-γ elevated. Subjective fatigue fell on FSS and sleep quality improved on PSQI. Excellent tolerability; no serious adverse events.
Conclusions
A standardized reishi water extract produced measurable immune-cell and symptom-domain improvements in healthy adults — the clearest modern human signal for the species' traditional use.
Worth noting
+34%/+42% NK numbers are substantial — the question is what functional meaning they carry in healthy people; immune activation is not automatically health benefit. Still, a clean double-blind design, n=84, a defined water extract, and convergent immune + symptom results make this among the better modern reishi data.