Efficacy and safety of Ojeok-san in Korean female patients with cold hypersensitivity in the hands and feet: study protocol for a randomized, double-blinded, placebo-controlled, multicenter pilot study

BACKGROUND: This study aims to evaluate the safety, efficacy, and feasibility of a full randomized clinical trial of Ojeok-san in Korean female patients with cold hypersensitivity in the hands and feet. METHODS: This study is a multicenter, double-blinded, randomized, placebo-controlled, two-arm, parallel-group pilot clinical trial. A total of 60 participants will be enrolled and randomly assigned to the Ojeok-san treatment group or the placebo control group, in a 1:1 ratio using an Internet-based randomization system. Each group will be administered Ojeok-san or placebo three times per day for 8 weeks. The primary outcome will be the mean change in the Visual Analog Scale scores of cold hypersensitivity in the hands from baseline to week 8. Secondary outcomes will include the mean changes in the skin temperature of the extremities, recovery rate of the skin temperature of hands after cold stress test, and the score of Korean version of the WHO Quality of Life Scale abbreviated version. DISCUSSION: The findings of this study should provide meaningful information for a further large-scale, randomized controlled trial to confirm the safety and efficacy of Ojeok-san on cold hypersensitivity in the hands and feet in female patients. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT03083522. Registered on 20 March 2017. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13063-018-3013-9) contains supplementary material, which is available to authorized users.