Efficacy and safety of the herbal formula Naesohwajung-tang for functional dyspepsia: a randomized, double-blind, placebo-controlled, multi-center trial

Background: Current treatment and management options for functional dyspepsia (FD) often fail to alleviate symptoms. Naesohwajung-tang (NHT) is a herbal formula frequently used to treat functional dyspepsia in traditional Korean medicine. However, few animal and case reports on the use of Naesohwajung-tang for functional dyspepsia treatment exist, and the clinical evidence remains deficient.Objectives: This study aimed to evaluate the efficacy of Naesohwajung-tang in patients with functional dyspepsia.Methods: We enrolled 116 patients with functional dyspepsia at two study sites in this 4 weeks, randomized, double-blind, placebo-controlled trial and randomly assigned them to either the Naesohwajung-tang or placebo group. To evaluate the efficacy of Naesohwajung-tang, the primary endpoint was a score on the total dyspepsia symptom (TDS) scale after treatment. The overall treatment effect (OTE), single dyspepsia symptom (SDS) scale, food retention questionnaire (FRQ), Damum questionnaire (DQ), functional dyspepsia-related quality of life (FD-QoL) questionnaire, and gastric myoelectrical activity measured using electrogastrography were evaluated as secondary outcomes. Laboratory tests were performed to confirm the safety of the intervention.Results: The 4 weeks administration of Naesohwajung-tang granules demonstrated a significantly higher reduction in the total dyspepsia symptom (p < 0.05) and a higher degree of improvement in the total dyspepsia symptom (p < 0.01) than the placebo group. Patients who underwent Naesohwajung-tang had a significantly higher overall treatment effect and a greater increase in the degree of improvement in scores such as epigastric burning, postprandial fullness, early satiation, functional dyspepsia-related quality of life, and Damum questionnaire (p < 0.05). Additionally, the Naesohwajung-tang group showed a greater effect in preventing a decrease in the percentage of normal gastric slow waves after meals than the placebo group. As a result of subgroup analyses using the degree of improvement in total dyspepsia symptom, Naesohwajung-tang was found to be more effective than placebo in female, younger patients (