Euiiyin-tang in the treatment of obesity: study protocol for a randomised controlled trial

BACKGROUND: Obesity is a public health concern in many countries due to its increasing prevalence. Euiiyin-tang is an herbal medicine formula often used as a clinical treatment for obesity. It acts to eliminate humidity and purify the blood, the causes of obesity identified by the theoretical framework of Korean medicine. The purpose of this study is to evaluate the efficacy and safety of Euiiyin-tang in treating obesity. METHODS/DESIGN: This study is a randomised, double-blinded and placebo-controlled, multicentre trial. It has two parallel arms: the Euiiyin-tang group and the placebo group. A total of 160 obese adult women will be enrolled in the trial. The participants will be randomly divided at a 1:1 ratio at visit 2 (baseline). The participants will be administered Euiiyin-tang or placebo for 12 weeks. The primary endpoint is the change in weight occurring between baseline and post-treatment. The secondary outcomes include average weight reduction, changes in body fat, waist and hip circumferences, body mass index, and lipid profile, and the results of questionnaires such as the Korean version of Obesity-related Quality of Life, the Korean version of Eating Attitudes Test, the Social Readjustment Rating Scale, and the Stress Reaction Inventory. DISCUSSION: The present study will provide research methodologies for evaluating the efficacy and safety of Euiiyin-tang in patients with obesity. In addition, it will provide evidence of correlation between obesity and Sasang constitutional medicine. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01724099. Registered on 2 November 2012. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13063-017-2039-8) contains supplementary material, which is available to authorized users.