Zao Ren An Shen capsule for chronic insomnia: Study protocol for a randomized, placebo-controlled trial

BACKGROUND: Zao Ren An Shen (ZRAS), a Chinese Herbal Medicine product, has been proposed as an alternative to recommended treatments for chronic insomnia. There is a lack of strong evidence supporting this proposition. AIMS: To assess the efficacy and safety of ZRAS capsule for chronic insomnia compared to placebo. METHODS: A parallel-group, double-blind, randomized-controlled trial will be performed in Western Sydney University, Australia. After a 1-week placebo run-in, adults with chronic insomnia (n = 90) will be randomized in a 1:1 ratio to receive either ZRAS capsule or placebo for 4 weeks. Insomnia severity (Insomnia Severity Scale score), sleep parameters (measured with the Consensus Sleep Diary and actigraphy), fatigue levels (Fatigue Severity Scale score), psychological status (Depression Anxiety Stress Scale score), quality of life (Assessment of Quality of Life score), and adverse events will be assessed at baseline, mid-treatment, post-treatment and at a 1-month follow-up. EXPECTED OUTCOMES: We hypothesize that ZRAS capsule will improve insomnia severity, sleep parameters, fatigue levels, psychological status, and quality of life better than placebo at mid-treatment, post-treatment, and follow-up. We also hypothesize that the number of adverse events provoked by ZRAS capsule will be similar to placebo at these time-points. TRIAL REGISTRATION: Australia New-Zealand Clinical Trial Registry (Registration number ACTRN12619000140156).