# Effectiveness and Safety of a Supplement Containing a Pharmacologically Active Basidiomycete Mushroom for Chronic Fatigue and Post–COVID-19 Fatigue Syndrome: Protocol for a Randomized Controlled Trial

## TL;DR

This study will test a mushroom supplement's effectiveness in reducing fatigue and its safety in patients with chronic fatigue and post-COVID fatigue.

## Contribution

The study introduces a clinical trial protocol to evaluate a lingzhi-based supplement for fatigue and its potential mechanisms.

## Key findings

- The trial will assess physical and mental fatigue reduction in participants with chronic or post-COVID fatigue.
- Associations between the supplement and inflammatory, immune, and oxidative stress biomarkers will be explored.
- Results will inform future clinical applications of traditional Chinese medicine for fatigue-related disorders.

## Abstract

Chronic fatigue syndrome, or myalgic encephalomyelitis, is characterized by persistent, unexplained exhaustion unalleviated by rest, with a pathophysiology distinct from underlying medical conditions. It is diagnostically complex due to symptoms that overlap with other disorders and the absence of definitive biomarkers, contributing to limited therapeutic options in current medicine. Lingzhi, a pharmacologically active basidiomycete mushroom, has been empirically used in traditional Chinese medicine for two millennia. This study has a dual focus: (1) systematically evaluating the efficacy and safety of lingzhi in managing chronic fatigue and post–COVID-19 fatigue syndrome and (2) elucidating its clinical associations with inflammatory, immune, and oxidative stress biomarkers to uncover potential therapeutic mechanisms.

The primary objective is to investigate whether a 6-week intake of CP003, a lingzhi-containing supplement, can reduce physical and mental fatigue in patients with chronic fatigue syndrome (ie, myalgic encephalomyelitis) or post–COVID-19 fatigue. Secondary objectives include assessing its effects on sleep quality, anxiety, depression, and general health status and exploring associations with inflammatory, immune, and oxidative stress biomarkers.

This randomized, waitlist-controlled trial will enroll 130 participants in Hong Kong, equally allocated (1:1) to either the CP003 intervention group or a waitlist control group. The intervention period spans 6 weeks, followed by a 6-week follow-up phase to assess the sustained effects. The trial data will be managed using REDCap (Research Electronic Data Capture) and analyzed via an intention-to-treat approach with inverse probability weighting for missing data, assessed through generalized linear regression (adjusted for covariates and interaction terms) at 6 and 12 weeks and supplemented by subgroup and sensitivity analyses in R, with results reported as mean differences (with 95% CIs) and P<.05 considered significant.

This study was funded in March 2024 (ITF/PRP/029/24FX). As of December 2025, all participants had been enrolled, but data entry had not yet commenced. Data analysis will commence after the completion of the 12-week follow-up for all participants. Results are expected to be submitted for publication in mid-2026. Safety outcomes will also be assessed and reported.

This trial will evaluate the efficacy and safety of CP003 for chronic fatigue and post–COVID-19 fatigue syndrome and explore potential underlying mechanisms of action. The findings will provide experimental data to inform future clinical applications and research on traditional Chinese medicine–based interventions for fatigue-related disorders.

ClinicalTrials.gov NCT06739720; https://clinicaltrials.gov/study/NCT06739720

PRR1-10.2196/82633