Effects of herbal medicines (

Background: Methods: A randomized, patient-assessor-blind, placebo-controlled, parallel, and multicenter clinical trial was conducted. Adult participants who had one or more cold within 48 h before screening, were randomly allocated to EKS, SSE, or placebo groups. The recruitment goal was planned to be 375 participants. They took an EKS, SSE, or placebo, thrice daily for up to 8 days. The primary outcome was the change in the total score of the Wisconsin Upper Respiratory Symptom Scale-21-Korean version (WURSS-21-K) on day 6 compared to the baseline. The secondary outcomes included visual analog scale (VAS) scores and the duration of symptoms was assessed throughout the trial. Results: A total of 128 participants were enrolled and 44, 42, and 42 were allocated to the EKS, SSE, and placebo groups, respectively. This study was prematurely terminated due to the COVID-19 pandemic, and we were unable to recruit all the planned participants ( Conclusions: Although EKS and SSE demonstrated statistically significant clinical effectiveness and safety in patients with the common cold, we failed to recruit our pre-planned number of participants. Future definitive full-scale studies are needed to confirm these results. Trial registration: ClinicalTrials. gov, registration number: NCT04073511. Registered on 29 August 2019.