This is a pilot, single-site clinical trial that will follow a randomized, double-blinded, parallel-group, placebo-controlled design. A total of 60 participants aged 18-65 will be recruited for a 12-week intervention, followed by a 4-week observational phase and a post-intervention visit at week 16. Participants will attend five scheduled visits at 4-week intervals (baseline, weeks 4, 8, 12, and 16) at the Specialist Clinical Centre for Teaching and Research, School of Chinese Medicine, the University of Hong Kong (HKUSCM). At each visit, assessments will include psychological attributes and sleep quality. Participants will be randomly allocated to one of 2 groups (n=30 per group): the intervention group, which will receive VCMBF and VCDSF, and the control group, which will receive a placebo matched for appearance, smell, and taste. Written informed consent will be obtained from each participant prior to the commencement of the study.
The primary outcome will be overall mental health, accessed by the Depression, Anxiety and Stress Scale - 21 items (DASS-21). Secondary outcomes will include anxiety status, measured by the Chinese version of the Beck Anxiety Inventory (BAI-C); depression status, measured by the Chinese version of the Beck Depression Inventory-II (C-BDI-II); stress levels, measured by the Perceived Stress Scale (PSS); psychological well-being, measured by the General Health Questionnaire-28 (GHQ-28); quality of life, assessed using the WHOQOL-BREF (Hong Kong version); and sleep quality, assessed using the Pittsburgh Sleep Quality Index (PSQI), the Mi wristband as an objective measure, and the Consensus Sleep Diary (CSD) for cross-validation. Tongue and pulse characteristics will also be recorded for qualitative analysis. Safety profiles of VCMBF and VCDSF will be evaluated throughout the study. Assessments will occur every four weeks until week 16, with tongue and pulse characteristics recorded at baseline, week 12, and week 16. A generalized linear mixed-effect model will be applied to compare outcomes over time in the 2 groups.